<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2024 Workiva-->
<!--r:6edb08b2-28be-4fe2-96a1-5228f16440ba,g:0b7981d4-3364-432a-a869-7a65f1514fac-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://www.cumberlandpharma.com/role/ConsolidatedStatementsofOperations" xlink:type="simple" xlink:href="cpix-20231231.xsd#ConsolidatedStatementsofOperations"/>
  <link:definitionLink xlink:role="http://www.cumberlandpharma.com/role/ConsolidatedStatementsofOperations" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_c91c6650-64bb-47f9-ba31-4ab7358debfe" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_07b916b2-05e0-4226-b0db-eed2669c4d0e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_c91c6650-64bb-47f9-ba31-4ab7358debfe" xlink:to="loc_us-gaap_StatementTable_07b916b2-05e0-4226-b0db-eed2669c4d0e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_fd71491b-20f9-4b25-bef7-5163743d16ab" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_07b916b2-05e0-4226-b0db-eed2669c4d0e" xlink:to="loc_srt_ProductOrServiceAxis_fd71491b-20f9-4b25-bef7-5163743d16ab" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_fd71491b-20f9-4b25-bef7-5163743d16ab_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_fd71491b-20f9-4b25-bef7-5163743d16ab" xlink:to="loc_srt_ProductsAndServicesDomain_fd71491b-20f9-4b25-bef7-5163743d16ab_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_d91bfb9d-1984-4aa1-b795-4de0af3cad00" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_fd71491b-20f9-4b25-bef7-5163743d16ab" xlink:to="loc_srt_ProductsAndServicesDomain_d91bfb9d-1984-4aa1-b795-4de0af3cad00" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductMember_36967a74-c403-4b3e-aca3-6d5ba8455cbf" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProductMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_d91bfb9d-1984-4aa1-b795-4de0af3cad00" xlink:to="loc_us-gaap_ProductMember_36967a74-c403-4b3e-aca3-6d5ba8455cbf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ManufacturedProductOtherMember_0e49d894-3378-449b-bc70-28c971d84ad2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ManufacturedProductOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_d91bfb9d-1984-4aa1-b795-4de0af3cad00" xlink:to="loc_us-gaap_ManufacturedProductOtherMember_0e49d894-3378-449b-bc70-28c971d84ad2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_68b32b7f-9a84-4746-abeb-6ac094881691" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_c91c6650-64bb-47f9-ba31-4ab7358debfe" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_68b32b7f-9a84-4746-abeb-6ac094881691" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostsAndExpensesAbstract_7a4d1a4f-9569-4e36-b9d0-c11418516f0d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CostsAndExpensesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_c91c6650-64bb-47f9-ba31-4ab7358debfe" xlink:to="loc_us-gaap_CostsAndExpensesAbstract_7a4d1a4f-9569-4e36-b9d0-c11418516f0d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_5b833643-7f69-4825-8cab-cd41fb215463" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CostOfGoodsAndServicesSold"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostsAndExpensesAbstract_7a4d1a4f-9569-4e36-b9d0-c11418516f0d" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_5b833643-7f69-4825-8cab-cd41fb215463" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingAndMarketingExpense_dd77bdad-06cd-4d34-9fad-dc1755e9afc1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SellingAndMarketingExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostsAndExpensesAbstract_7a4d1a4f-9569-4e36-b9d0-c11418516f0d" xlink:to="loc_us-gaap_SellingAndMarketingExpense_dd77bdad-06cd-4d34-9fad-dc1755e9afc1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpense_0e5b77eb-551b-49aa-aee3-d30c35008e95" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ResearchAndDevelopmentExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostsAndExpensesAbstract_7a4d1a4f-9569-4e36-b9d0-c11418516f0d" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpense_0e5b77eb-551b-49aa-aee3-d30c35008e95" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpense_5d7b7ad8-2dc1-4c66-9676-4395ab3ddbbe" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GeneralAndAdministrativeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostsAndExpensesAbstract_7a4d1a4f-9569-4e36-b9d0-c11418516f0d" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpense_5d7b7ad8-2dc1-4c66-9676-4395ab3ddbbe" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_b926249e-81d5-4d80-91f7-8f1e8590c093" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AmortizationOfIntangibleAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostsAndExpensesAbstract_7a4d1a4f-9569-4e36-b9d0-c11418516f0d" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_b926249e-81d5-4d80-91f7-8f1e8590c093" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostsAndExpenses_b1946114-0cba-4f17-8f7f-4b91dc80abf5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CostsAndExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostsAndExpensesAbstract_7a4d1a4f-9569-4e36-b9d0-c11418516f0d" xlink:to="loc_us-gaap_CostsAndExpenses_b1946114-0cba-4f17-8f7f-4b91dc80abf5" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_bd765521-9cce-4da7-b275-e6ce3721092f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostsAndExpensesAbstract_7a4d1a4f-9569-4e36-b9d0-c11418516f0d" xlink:to="loc_us-gaap_OperatingIncomeLoss_bd765521-9cce-4da7-b275-e6ce3721092f" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIncomeInterest_23ee84e6-8e0b-4da4-8b75-c075524a07a8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InvestmentIncomeInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_c91c6650-64bb-47f9-ba31-4ab7358debfe" xlink:to="loc_us-gaap_InvestmentIncomeInterest_23ee84e6-8e0b-4da4-8b75-c075524a07a8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherIncome_5bb71215-5da2-4dd1-b04d-4e3f31682fe8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherIncome"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_c91c6650-64bb-47f9-ba31-4ab7358debfe" xlink:to="loc_us-gaap_OtherIncome_5bb71215-5da2-4dd1-b04d-4e3f31682fe8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossRelatedToLitigationSettlement_1c612fa3-0147-4ce0-b2eb-45531bf46db3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GainLossRelatedToLitigationSettlement"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_c91c6650-64bb-47f9-ba31-4ab7358debfe" xlink:to="loc_us-gaap_GainLossRelatedToLitigationSettlement_1c612fa3-0147-4ce0-b2eb-45531bf46db3" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InsuredEventGainLoss_6bf19adb-20e3-4f09-b796-954c7ac13a4b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InsuredEventGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_c91c6650-64bb-47f9-ba31-4ab7358debfe" xlink:to="loc_us-gaap_InsuredEventGainLoss_6bf19adb-20e3-4f09-b796-954c7ac13a4b" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpense_f8e4ec3f-4644-4bf0-a5c6-5da9c4015837" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_c91c6650-64bb-47f9-ba31-4ab7358debfe" xlink:to="loc_us-gaap_InterestExpense_f8e4ec3f-4644-4bf0-a5c6-5da9c4015837" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_9ac941f0-03fd-4958-8b15-94b3ff4bc711" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_c91c6650-64bb-47f9-ba31-4ab7358debfe" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_9ac941f0-03fd-4958-8b15-94b3ff4bc711" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_0857d8b6-3932-416d-ad8d-5fb3760075ca" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_c91c6650-64bb-47f9-ba31-4ab7358debfe" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_0857d8b6-3932-416d-ad8d-5fb3760075ca" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_3a103792-f59f-46c3-bccc-de77769e2968" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_c91c6650-64bb-47f9-ba31-4ab7358debfe" xlink:to="loc_us-gaap_ProfitLoss_3a103792-f59f-46c3-bccc-de77769e2968" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_486618b2-b17e-464b-885e-f2cebe914035" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_c91c6650-64bb-47f9-ba31-4ab7358debfe" xlink:to="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_486618b2-b17e-464b-885e-f2cebe914035" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_6f2547fc-d380-474a-a90e-2f4af8343e94" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_c91c6650-64bb-47f9-ba31-4ab7358debfe" xlink:to="loc_us-gaap_NetIncomeLoss_6f2547fc-d380-474a-a90e-2f4af8343e94" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareAbstract_97318d54-cba7-4d34-9917-1e260c93844a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EarningsPerShareAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_c91c6650-64bb-47f9-ba31-4ab7358debfe" xlink:to="loc_us-gaap_EarningsPerShareAbstract_97318d54-cba7-4d34-9917-1e260c93844a" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasic_03c6bf04-3b6d-44b9-8c97-9052468bd0db" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EarningsPerShareBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareAbstract_97318d54-cba7-4d34-9917-1e260c93844a" xlink:to="loc_us-gaap_EarningsPerShareBasic_03c6bf04-3b6d-44b9-8c97-9052468bd0db" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDiluted_8d6244b8-9d95-4a1c-ad71-285ca87426e5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EarningsPerShareDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareAbstract_97318d54-cba7-4d34-9917-1e260c93844a" xlink:to="loc_us-gaap_EarningsPerShareDiluted_8d6244b8-9d95-4a1c-ad71-285ca87426e5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_f03d2a1d-d0fb-4a7f-987b-39c319e2590a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_c91c6650-64bb-47f9-ba31-4ab7358debfe" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_f03d2a1d-d0fb-4a7f-987b-39c319e2590a" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_20d8c464-a09f-4a62-9337-b25edea21efc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_f03d2a1d-d0fb-4a7f-987b-39c319e2590a" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_20d8c464-a09f-4a62-9337-b25edea21efc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_955e861d-8110-4690-b121-db60828e54ed" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_f03d2a1d-d0fb-4a7f-987b-39c319e2590a" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_955e861d-8110-4690-b121-db60828e54ed" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cumberlandpharma.com/role/ConsolidatedStatementsofEquity" xlink:type="simple" xlink:href="cpix-20231231.xsd#ConsolidatedStatementsofEquity"/>
  <link:definitionLink xlink:role="http://www.cumberlandpharma.com/role/ConsolidatedStatementsofEquity" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_f34816a2-ea84-49ff-8e8b-889fc1c17fab" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_eaea31e4-692d-4821-9c4e-30e5f4864c2a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_f34816a2-ea84-49ff-8e8b-889fc1c17fab" xlink:to="loc_us-gaap_StatementTable_eaea31e4-692d-4821-9c4e-30e5f4864c2a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_37bcc066-676b-46fb-9b33-5bc5c1d723fa" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_eaea31e4-692d-4821-9c4e-30e5f4864c2a" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_37bcc066-676b-46fb-9b33-5bc5c1d723fa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_37bcc066-676b-46fb-9b33-5bc5c1d723fa_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_37bcc066-676b-46fb-9b33-5bc5c1d723fa" xlink:to="loc_us-gaap_EquityComponentDomain_37bcc066-676b-46fb-9b33-5bc5c1d723fa_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_8a08b8ac-8120-464a-b2b7-7225a6c9ada2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_37bcc066-676b-46fb-9b33-5bc5c1d723fa" xlink:to="loc_us-gaap_EquityComponentDomain_8a08b8ac-8120-464a-b2b7-7225a6c9ada2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_a7f23e7b-ec3c-46d3-81f6-2426e2db5bbf" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_8a08b8ac-8120-464a-b2b7-7225a6c9ada2" xlink:to="loc_us-gaap_CommonStockMember_a7f23e7b-ec3c-46d3-81f6-2426e2db5bbf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_ba4ede33-0696-4598-8884-8cc5e8e760b1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_8a08b8ac-8120-464a-b2b7-7225a6c9ada2" xlink:to="loc_us-gaap_RetainedEarningsMember_ba4ede33-0696-4598-8884-8cc5e8e760b1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestMember_0490ff12-8806-45b7-9054-9328b00b55fd" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NoncontrollingInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_8a08b8ac-8120-464a-b2b7-7225a6c9ada2" xlink:to="loc_us-gaap_NoncontrollingInterestMember_0490ff12-8806-45b7-9054-9328b00b55fd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_31e74e44-f185-4e7e-8162-49655371bab2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_f34816a2-ea84-49ff-8e8b-889fc1c17fab" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_31e74e44-f185-4e7e-8162-49655371bab2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_681335d2-ac3e-4c22-bf8a-68594e548a1d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_31e74e44-f185-4e7e-8162-49655371bab2" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_681335d2-ac3e-4c22-bf8a-68594e548a1d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_43d4f0ce-cd59-4e85-971b-3fbf8a390684" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_31e74e44-f185-4e7e-8162-49655371bab2" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_43d4f0ce-cd59-4e85-971b-3fbf8a390684" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_3798e89e-f2a1-4842-b0f4-9813e4f025a2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_31e74e44-f185-4e7e-8162-49655371bab2" xlink:to="loc_us-gaap_ProfitLoss_3798e89e-f2a1-4842-b0f4-9813e4f025a2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRedeemedOrCalledDuringPeriodShares_106eaf0e-3776-461d-a39b-478e3781d217" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockRedeemedOrCalledDuringPeriodShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_31e74e44-f185-4e7e-8162-49655371bab2" xlink:to="loc_us-gaap_StockRedeemedOrCalledDuringPeriodShares_106eaf0e-3776-461d-a39b-478e3781d217" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRedeemedOrCalledDuringPeriodValue_6ddc53b4-becf-4925-a662-21f6341e557b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockRedeemedOrCalledDuringPeriodValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_31e74e44-f185-4e7e-8162-49655371bab2" xlink:to="loc_us-gaap_StockRedeemedOrCalledDuringPeriodValue_6ddc53b4-becf-4925-a662-21f6341e557b" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_436d86e9-7d94-4542-859c-975cadd68aba" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_31e74e44-f185-4e7e-8162-49655371bab2" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_436d86e9-7d94-4542-859c-975cadd68aba" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_c039445a-e0b6-4dac-86f3-bec9f4d9a033" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_31e74e44-f185-4e7e-8162-49655371bab2" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_c039445a-e0b6-4dac-86f3-bec9f4d9a033" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodShares_6b5be975-ccc6-44b3-b66b-828beb70521f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockRepurchasedDuringPeriodShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_31e74e44-f185-4e7e-8162-49655371bab2" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodShares_6b5be975-ccc6-44b3-b66b-828beb70521f" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodValue_32cd3d8c-e139-4ff8-904e-4ca156ad9b0c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockRepurchasedDuringPeriodValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_31e74e44-f185-4e7e-8162-49655371bab2" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodValue_32cd3d8c-e139-4ff8-904e-4ca156ad9b0c" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_75b28116-026c-420e-8918-2a987d4f10df" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_32d71ffe-fcc7-47b7-b08f-cfcaccc29ea9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cumberlandpharma.com/role/OrganizationNarrativeDetails" xlink:type="simple" xlink:href="cpix-20231231.xsd#OrganizationNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.cumberlandpharma.com/role/OrganizationNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityInformationLineItems_282d56a7-e802-4a70-9d44-3f512528da57" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntitiesTable_e843a44c-8eb1-4669-a0e4-1e8eb9e2542e" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntitiesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dei_EntityInformationLineItems_282d56a7-e802-4a70-9d44-3f512528da57" xlink:to="loc_dei_EntitiesTable_e843a44c-8eb1-4669-a0e4-1e8eb9e2542e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_bf6ca88b-993a-4380-83dd-2849791f5629" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_EntitiesTable_e843a44c-8eb1-4669-a0e4-1e8eb9e2542e" xlink:to="loc_dei_LegalEntityAxis_bf6ca88b-993a-4380-83dd-2849791f5629" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_bf6ca88b-993a-4380-83dd-2849791f5629_default" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_bf6ca88b-993a-4380-83dd-2849791f5629" xlink:to="loc_dei_EntityDomain_bf6ca88b-993a-4380-83dd-2849791f5629_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_52610ad2-9ebf-45be-81f4-4ebd671d5111" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_bf6ca88b-993a-4380-83dd-2849791f5629" xlink:to="loc_dei_EntityDomain_52610ad2-9ebf-45be-81f4-4ebd671d5111" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_CumberlandEmergingTechnologiesIncMember_031c75d2-d766-46eb-b0e5-40657cce4c79" xlink:href="cpix-20231231.xsd#cpix_CumberlandEmergingTechnologiesIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_52610ad2-9ebf-45be-81f4-4ebd671d5111" xlink:to="loc_cpix_CumberlandEmergingTechnologiesIncMember_031c75d2-d766-46eb-b0e5-40657cce4c79" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_1afcc298-67c1-47b7-bf60-9de954f377db" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_CounterpartyNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_EntitiesTable_e843a44c-8eb1-4669-a0e4-1e8eb9e2542e" xlink:to="loc_srt_CounterpartyNameAxis_1afcc298-67c1-47b7-bf60-9de954f377db" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_1afcc298-67c1-47b7-bf60-9de954f377db_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_1afcc298-67c1-47b7-bf60-9de954f377db" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_1afcc298-67c1-47b7-bf60-9de954f377db_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_beccb878-685a-42c0-878c-86e2d3f2a68a" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_1afcc298-67c1-47b7-bf60-9de954f377db" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_beccb878-685a-42c0-878c-86e2d3f2a68a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_HongKongWinHealthPharmaGroupCoLimitedMember_9199eab0-55a5-48cc-b67e-ffac91c07820" xlink:href="cpix-20231231.xsd#cpix_HongKongWinHealthPharmaGroupCoLimitedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_beccb878-685a-42c0-878c-86e2d3f2a68a" xlink:to="loc_cpix_HongKongWinHealthPharmaGroupCoLimitedMember_9199eab0-55a5-48cc-b67e-ffac91c07820" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipAxis_b016a6a9-f95c-467c-8d95-c5b0b553390c" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_OwnershipAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_EntitiesTable_e843a44c-8eb1-4669-a0e4-1e8eb9e2542e" xlink:to="loc_srt_OwnershipAxis_b016a6a9-f95c-467c-8d95-c5b0b553390c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_b016a6a9-f95c-467c-8d95-c5b0b553390c_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_OwnershipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_OwnershipAxis_b016a6a9-f95c-467c-8d95-c5b0b553390c" xlink:to="loc_srt_OwnershipDomain_b016a6a9-f95c-467c-8d95-c5b0b553390c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_49742183-96e0-4d8a-8f9b-0b1dd721069e" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_OwnershipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_OwnershipAxis_b016a6a9-f95c-467c-8d95-c5b0b553390c" xlink:to="loc_srt_OwnershipDomain_49742183-96e0-4d8a-8f9b-0b1dd721069e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_CumberlandEmergingTechnologiesIncMember_f68f1ea7-7a69-4f8f-820a-6a898853e199" xlink:href="cpix-20231231.xsd#cpix_CumberlandEmergingTechnologiesIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_OwnershipDomain_49742183-96e0-4d8a-8f9b-0b1dd721069e" xlink:to="loc_cpix_CumberlandEmergingTechnologiesIncMember_f68f1ea7-7a69-4f8f-820a-6a898853e199" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestAbstract_48fe95cc-bae3-40b9-8490-2dd26cee8f7c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NoncontrollingInterestAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_282d56a7-e802-4a70-9d44-3f512528da57" xlink:to="loc_us-gaap_NoncontrollingInterestAbstract_48fe95cc-bae3-40b9-8490-2dd26cee8f7c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_SubsidiaryInvestmentPurchaseOfShares_c7bec69e-2b7a-4d8b-9b82-8f49c35fcf49" xlink:href="cpix-20231231.xsd#cpix_SubsidiaryInvestmentPurchaseOfShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoncontrollingInterestAbstract_48fe95cc-bae3-40b9-8490-2dd26cee8f7c" xlink:to="loc_cpix_SubsidiaryInvestmentPurchaseOfShares_c7bec69e-2b7a-4d8b-9b82-8f49c35fcf49" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestOwnershipPercentageByParent_290b207d-cb77-44c4-ade8-af3ff288966a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MinorityInterestOwnershipPercentageByParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoncontrollingInterestAbstract_48fe95cc-bae3-40b9-8490-2dd26cee8f7c" xlink:to="loc_us-gaap_MinorityInterestOwnershipPercentageByParent_290b207d-cb77-44c4-ade8-af3ff288966a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_236f1fdb-3fb8-4e17-b64c-3c41c5bd0fc6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoncontrollingInterestAbstract_48fe95cc-bae3-40b9-8490-2dd26cee8f7c" xlink:to="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_236f1fdb-3fb8-4e17-b64c-3c41c5bd0fc6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_SharebasedCompensationCharitableContributionofSharesShares_2c7647ff-3a7f-4b2c-bfdd-12340dce75af" xlink:href="cpix-20231231.xsd#cpix_SharebasedCompensationCharitableContributionofSharesShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoncontrollingInterestAbstract_48fe95cc-bae3-40b9-8490-2dd26cee8f7c" xlink:to="loc_cpix_SharebasedCompensationCharitableContributionofSharesShares_2c7647ff-3a7f-4b2c-bfdd-12340dce75af" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ShareBasedCompensationCharitableContributionOfSharesCashContributions_2d035f6d-09e0-4aa9-9e02-c1223132cbf0" xlink:href="cpix-20231231.xsd#cpix_ShareBasedCompensationCharitableContributionOfSharesCashContributions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoncontrollingInterestAbstract_48fe95cc-bae3-40b9-8490-2dd26cee8f7c" xlink:to="loc_cpix_ShareBasedCompensationCharitableContributionOfSharesCashContributions_2d035f6d-09e0-4aa9-9e02-c1223132cbf0" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cumberlandpharma.com/role/SignificantAccountingPoliciesNarrativeDetails" xlink:type="simple" xlink:href="cpix-20231231.xsd#SignificantAccountingPoliciesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.cumberlandpharma.com/role/SignificantAccountingPoliciesNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeasedAssetsLineItems_a30007fb-b6a3-4d2e-a207-e0ccbf5d38ff" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeasedAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfOperatingLeasedAssetsTable_bc888736-f015-4c54-bb70-6474b99b3ebb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfOperatingLeasedAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_OperatingLeasedAssetsLineItems_a30007fb-b6a3-4d2e-a207-e0ccbf5d38ff" xlink:to="loc_us-gaap_ScheduleOfOperatingLeasedAssetsTable_bc888736-f015-4c54-bb70-6474b99b3ebb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_8b86baf9-5a50-493a-819e-a709fc8d40cd" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_CounterpartyNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfOperatingLeasedAssetsTable_bc888736-f015-4c54-bb70-6474b99b3ebb" xlink:to="loc_srt_CounterpartyNameAxis_8b86baf9-5a50-493a-819e-a709fc8d40cd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_8b86baf9-5a50-493a-819e-a709fc8d40cd_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_8b86baf9-5a50-493a-819e-a709fc8d40cd" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_8b86baf9-5a50-493a-819e-a709fc8d40cd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_67268de5-9ff4-40f0-9847-5e4fa0f848f1" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_8b86baf9-5a50-493a-819e-a709fc8d40cd" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_67268de5-9ff4-40f0-9847-5e4fa0f848f1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_WinHealthInvestmentSingaporeLtdMember_eed8d81b-67f6-46ea-b5a1-8095ed3b2b7d" xlink:href="cpix-20231231.xsd#cpix_WinHealthInvestmentSingaporeLtdMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_67268de5-9ff4-40f0-9847-5e4fa0f848f1" xlink:to="loc_cpix_WinHealthInvestmentSingaporeLtdMember_eed8d81b-67f6-46ea-b5a1-8095ed3b2b7d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_MartinS.BrownJr.sLawFirmMember_2ad0a75f-a5a0-4e55-8946-250509f30434" xlink:href="cpix-20231231.xsd#cpix_MartinS.BrownJr.sLawFirmMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_67268de5-9ff4-40f0-9847-5e4fa0f848f1" xlink:to="loc_cpix_MartinS.BrownJr.sLawFirmMember_2ad0a75f-a5a0-4e55-8946-250509f30434" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_bdba99a7-95b1-477e-9f3d-ab4904a57ed5" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfOperatingLeasedAssetsTable_bc888736-f015-4c54-bb70-6474b99b3ebb" xlink:to="loc_srt_StatementGeographicalAxis_bdba99a7-95b1-477e-9f3d-ab4904a57ed5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_bdba99a7-95b1-477e-9f3d-ab4904a57ed5_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_bdba99a7-95b1-477e-9f3d-ab4904a57ed5" xlink:to="loc_srt_SegmentGeographicalDomain_bdba99a7-95b1-477e-9f3d-ab4904a57ed5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_b6808417-6cdd-453c-ac32-e0e44ef40679" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_bdba99a7-95b1-477e-9f3d-ab4904a57ed5" xlink:to="loc_srt_SegmentGeographicalDomain_b6808417-6cdd-453c-ac32-e0e44ef40679" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonUsMember_ce9b4e95-4179-4aa1-b1ba-df97b57b9376" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NonUsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_b6808417-6cdd-453c-ac32-e0e44ef40679" xlink:to="loc_us-gaap_NonUsMember_ce9b4e95-4179-4aa1-b1ba-df97b57b9376" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_AccountsReceivableAllowancesByComponentAxis_b1f9e666-d008-4184-8e4c-3f11e0318650" xlink:href="cpix-20231231.xsd#cpix_AccountsReceivableAllowancesByComponentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfOperatingLeasedAssetsTable_bc888736-f015-4c54-bb70-6474b99b3ebb" xlink:to="loc_cpix_AccountsReceivableAllowancesByComponentAxis_b1f9e666-d008-4184-8e4c-3f11e0318650" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_AccountsReceivableAllowancesByComponentDomain_b1f9e666-d008-4184-8e4c-3f11e0318650_default" xlink:href="cpix-20231231.xsd#cpix_AccountsReceivableAllowancesByComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_cpix_AccountsReceivableAllowancesByComponentAxis_b1f9e666-d008-4184-8e4c-3f11e0318650" xlink:to="loc_cpix_AccountsReceivableAllowancesByComponentDomain_b1f9e666-d008-4184-8e4c-3f11e0318650_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_AccountsReceivableAllowancesByComponentDomain_6e2f7d7b-86c6-41be-b0cf-965d3b2b6061" xlink:href="cpix-20231231.xsd#cpix_AccountsReceivableAllowancesByComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_cpix_AccountsReceivableAllowancesByComponentAxis_b1f9e666-d008-4184-8e4c-3f11e0318650" xlink:to="loc_cpix_AccountsReceivableAllowancesByComponentDomain_6e2f7d7b-86c6-41be-b0cf-965d3b2b6061" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ChargebacksCashDiscountsAndDamagedGoodsMember_91c96e6a-dad1-4ca4-aa0f-d3c24becfea8" xlink:href="cpix-20231231.xsd#cpix_ChargebacksCashDiscountsAndDamagedGoodsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cpix_AccountsReceivableAllowancesByComponentDomain_6e2f7d7b-86c6-41be-b0cf-965d3b2b6061" xlink:to="loc_cpix_ChargebacksCashDiscountsAndDamagedGoodsMember_91c96e6a-dad1-4ca4-aa0f-d3c24becfea8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionAxis_267ec083-ad78-4d27-a203-21d753d9fd6d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyTransactionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfOperatingLeasedAssetsTable_bc888736-f015-4c54-bb70-6474b99b3ebb" xlink:to="loc_us-gaap_RelatedPartyTransactionAxis_267ec083-ad78-4d27-a203-21d753d9fd6d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionDomain_267ec083-ad78-4d27-a203-21d753d9fd6d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionAxis_267ec083-ad78-4d27-a203-21d753d9fd6d" xlink:to="loc_us-gaap_RelatedPartyTransactionDomain_267ec083-ad78-4d27-a203-21d753d9fd6d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionDomain_28b0a147-4b0d-4ef6-b72b-22d536cbc56a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionAxis_267ec083-ad78-4d27-a203-21d753d9fd6d" xlink:to="loc_us-gaap_RelatedPartyTransactionDomain_28b0a147-4b0d-4ef6-b72b-22d536cbc56a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember_a9bf4acb-9cdd-403b-b5a0-9a78e10dfeef" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionDomain_28b0a147-4b0d-4ef6-b72b-22d536cbc56a" xlink:to="loc_us-gaap_RelatedPartyMember_a9bf4acb-9cdd-403b-b5a0-9a78e10dfeef" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingAbstract_c410eaed-4191-40c9-8cf2-d13291442cea" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SegmentReportingAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLeasedAssetsLineItems_a30007fb-b6a3-4d2e-a207-e0ccbf5d38ff" xlink:to="loc_us-gaap_SegmentReportingAbstract_c410eaed-4191-40c9-8cf2-d13291442cea" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfOperatingSegments_7293519c-5a91-4214-a418-b4ef55215da9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NumberOfOperatingSegments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingAbstract_c410eaed-4191-40c9-8cf2-d13291442cea" xlink:to="loc_us-gaap_NumberOfOperatingSegments_7293519c-5a91-4214-a418-b4ef55215da9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_a45a2099-107d-4038-926c-a89e77e6d364" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingAbstract_c410eaed-4191-40c9-8cf2-d13291442cea" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_a45a2099-107d-4038-926c-a89e77e6d364" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_16c00f7f-661a-44c4-8ebe-4f08b195534b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingAbstract_c410eaed-4191-40c9-8cf2-d13291442cea" xlink:to="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_16c00f7f-661a-44c4-8ebe-4f08b195534b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_StockIssuedDuringPeriodShelfRegistrationProceedsFromSaleofCorporateSecurities_f6a9a3f3-c9f4-48cd-a6a2-43831081bd8a" xlink:href="cpix-20231231.xsd#cpix_StockIssuedDuringPeriodShelfRegistrationProceedsFromSaleofCorporateSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingAbstract_c410eaed-4191-40c9-8cf2-d13291442cea" xlink:to="loc_cpix_StockIssuedDuringPeriodShelfRegistrationProceedsFromSaleofCorporateSecurities_f6a9a3f3-c9f4-48cd-a6a2-43831081bd8a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairmentOfIntangibleAssetsFinitelived_9f26cd75-a93b-4ff7-93b4-2457b3234268" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ImpairmentOfIntangibleAssetsFinitelived"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingAbstract_c410eaed-4191-40c9-8cf2-d13291442cea" xlink:to="loc_us-gaap_ImpairmentOfIntangibleAssetsFinitelived_9f26cd75-a93b-4ff7-93b4-2457b3234268" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillImpairmentLoss_5662c924-565c-4992-8fcd-5aaf633f1359" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GoodwillImpairmentLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingAbstract_c410eaed-4191-40c9-8cf2-d13291442cea" xlink:to="loc_us-gaap_GoodwillImpairmentLoss_5662c924-565c-4992-8fcd-5aaf633f1359" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures_4a50aa3c-fdea-4605-99e2-71e8adb206f5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingAbstract_c410eaed-4191-40c9-8cf2-d13291442cea" xlink:to="loc_us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures_4a50aa3c-fdea-4605-99e2-71e8adb206f5" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostsAndExpenses_959043c0-a728-4b4b-97ba-b09c9318547f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CostsAndExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingAbstract_c410eaed-4191-40c9-8cf2-d13291442cea" xlink:to="loc_us-gaap_CostsAndExpenses_959043c0-a728-4b4b-97ba-b09c9318547f" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cumberlandpharma.com/role/VibativSancusoandRediTrexProductsNarrativeDetails" xlink:type="simple" xlink:href="cpix-20231231.xsd#VibativSancusoandRediTrexProductsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.cumberlandpharma.com/role/VibativSancusoandRediTrexProductsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_34003409-3447-4d8c-aa92-4cc67de5cef3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_38d2875e-825b-42a6-b7f0-d0952a604ca9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_34003409-3447-4d8c-aa92-4cc67de5cef3" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_38d2875e-825b-42a6-b7f0-d0952a604ca9" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_0ab6c7f0-8f81-4f80-a4a0-b830c7fa5b5b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_38d2875e-825b-42a6-b7f0-d0952a604ca9" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_0ab6c7f0-8f81-4f80-a4a0-b830c7fa5b5b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_0ab6c7f0-8f81-4f80-a4a0-b830c7fa5b5b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_0ab6c7f0-8f81-4f80-a4a0-b830c7fa5b5b" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_0ab6c7f0-8f81-4f80-a4a0-b830c7fa5b5b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_45f01dcd-495e-42c0-a994-906e2228915b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_0ab6c7f0-8f81-4f80-a4a0-b830c7fa5b5b" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_45f01dcd-495e-42c0-a994-906e2228915b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ProductAssetsAndGlobalRightsVibativMember_b056391e-e951-4ac1-a275-cabf1a96164d" xlink:href="cpix-20231231.xsd#cpix_ProductAssetsAndGlobalRightsVibativMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_45f01dcd-495e-42c0-a994-906e2228915b" xlink:to="loc_cpix_ProductAssetsAndGlobalRightsVibativMember_b056391e-e951-4ac1-a275-cabf1a96164d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_U.S.ProductAssetRightsSancusoMember_ad682603-f2f3-4093-aeae-b18315e67d46" xlink:href="cpix-20231231.xsd#cpix_U.S.ProductAssetRightsSancusoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_45f01dcd-495e-42c0-a994-906e2228915b" xlink:to="loc_cpix_U.S.ProductAssetRightsSancusoMember_ad682603-f2f3-4093-aeae-b18315e67d46" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_741106c1-75cd-4711-8de8-406f63079c58" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_38d2875e-825b-42a6-b7f0-d0952a604ca9" xlink:to="loc_srt_RangeAxis_741106c1-75cd-4711-8de8-406f63079c58" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_741106c1-75cd-4711-8de8-406f63079c58_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_741106c1-75cd-4711-8de8-406f63079c58" xlink:to="loc_srt_RangeMember_741106c1-75cd-4711-8de8-406f63079c58_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_fc9cc1a2-2386-49c4-808d-3a3b066c4ea7" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_741106c1-75cd-4711-8de8-406f63079c58" xlink:to="loc_srt_RangeMember_fc9cc1a2-2386-49c4-808d-3a3b066c4ea7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_c6ffbf54-a172-4ad4-9e72-9cd3b0ad298e" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_fc9cc1a2-2386-49c4-808d-3a3b066c4ea7" xlink:to="loc_srt_MaximumMember_c6ffbf54-a172-4ad4-9e72-9cd3b0ad298e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesGross_9b3df18c-1859-43fd-a2c2-a446306d533b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsToAcquireBusinessesGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_34003409-3447-4d8c-aa92-4cc67de5cef3" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesGross_9b3df18c-1859-43fd-a2c2-a446306d533b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_PaymentsToAcquireBusinessMilestonePayment_5b2611d7-cf5f-413c-badb-ed3098ebb018" xlink:href="cpix-20231231.xsd#cpix_PaymentsToAcquireBusinessMilestonePayment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_34003409-3447-4d8c-aa92-4cc67de5cef3" xlink:to="loc_cpix_PaymentsToAcquireBusinessMilestonePayment_5b2611d7-cf5f-413c-badb-ed3098ebb018" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_PaymentsToAcquireBusinessTieredRoyaltyPaymentsPercentage_d263eb13-ad3d-465f-94b6-001819c6cad8" xlink:href="cpix-20231231.xsd#cpix_PaymentsToAcquireBusinessTieredRoyaltyPaymentsPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_34003409-3447-4d8c-aa92-4cc67de5cef3" xlink:to="loc_cpix_PaymentsToAcquireBusinessTieredRoyaltyPaymentsPercentage_d263eb13-ad3d-465f-94b6-001819c6cad8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_PaymentsToAcquireBusinessTieredRoyaltyPaymentsThreshold_cb0883d9-06ad-4551-bc48-b4944d849405" xlink:href="cpix-20231231.xsd#cpix_PaymentsToAcquireBusinessTieredRoyaltyPaymentsThreshold"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_34003409-3447-4d8c-aa92-4cc67de5cef3" xlink:to="loc_cpix_PaymentsToAcquireBusinessTieredRoyaltyPaymentsThreshold_cb0883d9-06ad-4551-bc48-b4944d849405" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiabilityCurrent_4fb0f0aa-3b7e-4743-80ed-bf3ea8fff291" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationContingentConsiderationLiabilityCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_34003409-3447-4d8c-aa92-4cc67de5cef3" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiabilityCurrent_4fb0f0aa-3b7e-4743-80ed-bf3ea8fff291" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiabilityNoncurrent_0538d905-e536-4585-a1fe-0ae501f20309" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationContingentConsiderationLiabilityNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_34003409-3447-4d8c-aa92-4cc67de5cef3" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiabilityNoncurrent_0538d905-e536-4585-a1fe-0ae501f20309" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_PaymentsToAcquireBusinessMilestonePaymentRemaining_5b93ba17-0f9c-4ba4-8caf-0eaa8ba3eaef" xlink:href="cpix-20231231.xsd#cpix_PaymentsToAcquireBusinessMilestonePaymentRemaining"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_34003409-3447-4d8c-aa92-4cc67de5cef3" xlink:to="loc_cpix_PaymentsToAcquireBusinessMilestonePaymentRemaining_5b93ba17-0f9c-4ba4-8caf-0eaa8ba3eaef" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedContingentLiability_baae6b22-358a-4cb9-861b-9102d958cbd9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedContingentLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_34003409-3447-4d8c-aa92-4cc67de5cef3" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedContingentLiability_baae6b22-358a-4cb9-861b-9102d958cbd9" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets_8e6ecb17-97b6-4f16-bc1a-fe1982fe6c4d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_34003409-3447-4d8c-aa92-4cc67de5cef3" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets_8e6ecb17-97b6-4f16-bc1a-fe1982fe6c4d" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory_86646bd2-2240-4d5f-952f-5d3968044932" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_34003409-3447-4d8c-aa92-4cc67de5cef3" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory_86646bd2-2240-4d5f-952f-5d3968044932" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_a8403eaa-0317-41a9-94ed-6b27551a9124" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_34003409-3447-4d8c-aa92-4cc67de5cef3" xlink:to="loc_us-gaap_Goodwill_a8403eaa-0317-41a9-94ed-6b27551a9124" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_b1040a2d-5cf9-466c-ab65-cbd3643ff253" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_34003409-3447-4d8c-aa92-4cc67de5cef3" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_b1040a2d-5cf9-466c-ab65-cbd3643ff253" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedMilestonePayable_f19dd984-d6c9-4131-bb24-baa317404f29" xlink:href="cpix-20231231.xsd#cpix_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedMilestonePayable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_34003409-3447-4d8c-aa92-4cc67de5cef3" xlink:to="loc_cpix_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedMilestonePayable_f19dd984-d6c9-4131-bb24-baa317404f29" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_25c8459b-8849-4a50-82fa-67560b7a4f00" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable_141985df-4a72-461a-9043-ae4024a2a87f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_25c8459b-8849-4a50-82fa-67560b7a4f00" xlink:to="loc_us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable_141985df-4a72-461a-9043-ae4024a2a87f" xlink:type="arc" order="2" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_b4f357e9-cffc-4cd2-ab60-7bc28477d5c0" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_CounterpartyNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable_141985df-4a72-461a-9043-ae4024a2a87f" xlink:to="loc_srt_CounterpartyNameAxis_b4f357e9-cffc-4cd2-ab60-7bc28477d5c0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_b4f357e9-cffc-4cd2-ab60-7bc28477d5c0_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_b4f357e9-cffc-4cd2-ab60-7bc28477d5c0" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_b4f357e9-cffc-4cd2-ab60-7bc28477d5c0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_59ad923f-6af4-4b68-9f11-5add72c91955" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_b4f357e9-cffc-4cd2-ab60-7bc28477d5c0" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_59ad923f-6af4-4b68-9f11-5add72c91955" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_NordicGroupBVMember_1a497356-1b7b-44be-8de0-98727b63b04b" xlink:href="cpix-20231231.xsd#cpix_NordicGroupBVMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_59ad923f-6af4-4b68-9f11-5add72c91955" xlink:to="loc_cpix_NordicGroupBVMember_1a497356-1b7b-44be-8de0-98727b63b04b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_9032ac38-5fae-4047-afff-2005392b2a4b" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable_141985df-4a72-461a-9043-ae4024a2a87f" xlink:to="loc_srt_ProductOrServiceAxis_9032ac38-5fae-4047-afff-2005392b2a4b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_9032ac38-5fae-4047-afff-2005392b2a4b_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_9032ac38-5fae-4047-afff-2005392b2a4b" xlink:to="loc_srt_ProductsAndServicesDomain_9032ac38-5fae-4047-afff-2005392b2a4b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_29a527e9-5a50-4e5a-9ba9-e7f4e6ff1966" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_9032ac38-5fae-4047-afff-2005392b2a4b" xlink:to="loc_srt_ProductsAndServicesDomain_29a527e9-5a50-4e5a-9ba9-e7f4e6ff1966" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_MethotrexateMember_09c7c8fc-389f-463a-9421-fa9b7eaaea31" xlink:href="cpix-20231231.xsd#cpix_MethotrexateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_29a527e9-5a50-4e5a-9ba9-e7f4e6ff1966" xlink:to="loc_cpix_MethotrexateMember_09c7c8fc-389f-463a-9421-fa9b7eaaea31" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TypeOfArrangementAxis_6d0409e6-f7f4-47de-9efe-3b5fcbc86ca7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TypeOfArrangementAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable_141985df-4a72-461a-9043-ae4024a2a87f" xlink:to="loc_us-gaap_TypeOfArrangementAxis_6d0409e6-f7f4-47de-9efe-3b5fcbc86ca7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_6d0409e6-f7f4-47de-9efe-3b5fcbc86ca7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TypeOfArrangementAxis_6d0409e6-f7f4-47de-9efe-3b5fcbc86ca7" xlink:to="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_6d0409e6-f7f4-47de-9efe-3b5fcbc86ca7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_e96e9544-5c05-4575-9a67-bcc646371f14" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TypeOfArrangementAxis_6d0409e6-f7f4-47de-9efe-3b5fcbc86ca7" xlink:to="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_e96e9544-5c05-4575-9a67-bcc646371f14" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollaborativeArrangementTransactionWithPartyToCollaborativeArrangementMember_a54b40a6-dd71-474c-b52a-2952b2546a48" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CollaborativeArrangementTransactionWithPartyToCollaborativeArrangementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_e96e9544-5c05-4575-9a67-bcc646371f14" xlink:to="loc_us-gaap_CollaborativeArrangementTransactionWithPartyToCollaborativeArrangementMember_a54b40a6-dd71-474c-b52a-2952b2546a48" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_cc3b1ebd-0471-4865-a425-677934d8e213" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable_141985df-4a72-461a-9043-ae4024a2a87f" xlink:to="loc_us-gaap_AwardTypeAxis_cc3b1ebd-0471-4865-a425-677934d8e213" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_cc3b1ebd-0471-4865-a425-677934d8e213_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_cc3b1ebd-0471-4865-a425-677934d8e213" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_cc3b1ebd-0471-4865-a425-677934d8e213_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1b883030-41d8-4785-a9bc-27492fd05516" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_cc3b1ebd-0471-4865-a425-677934d8e213" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1b883030-41d8-4785-a9bc-27492fd05516" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_104a7051-01aa-4872-ac8d-c62fea5334d7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1b883030-41d8-4785-a9bc-27492fd05516" xlink:to="loc_us-gaap_RestrictedStockMember_104a7051-01aa-4872-ac8d-c62fea5334d7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_CollaborativeArrangementRightsAndObligationsDepositPayment_5b21beab-6987-4d2e-bf30-803cbc25a01b" xlink:href="cpix-20231231.xsd#cpix_CollaborativeArrangementRightsAndObligationsDepositPayment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_25c8459b-8849-4a50-82fa-67560b7a4f00" xlink:to="loc_cpix_CollaborativeArrangementRightsAndObligationsDepositPayment_5b21beab-6987-4d2e-bf30-803cbc25a01b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_CollaborativeArrangementRightsAndObligationsStockConsiderationValue_9722466a-9875-4ccc-aa19-63d8255d7df0" xlink:href="cpix-20231231.xsd#cpix_CollaborativeArrangementRightsAndObligationsStockConsiderationValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_25c8459b-8849-4a50-82fa-67560b7a4f00" xlink:to="loc_cpix_CollaborativeArrangementRightsAndObligationsStockConsiderationValue_9722466a-9875-4ccc-aa19-63d8255d7df0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_CollaborativeArrangementRightsAndObligationsStockConsiderationShares_8ddf4418-67a7-42bd-9008-572f17a6077e" xlink:href="cpix-20231231.xsd#cpix_CollaborativeArrangementRightsAndObligationsStockConsiderationShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_25c8459b-8849-4a50-82fa-67560b7a4f00" xlink:to="loc_cpix_CollaborativeArrangementRightsAndObligationsStockConsiderationShares_8ddf4418-67a7-42bd-9008-572f17a6077e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_CollaborativeArrangementRightsAndObligationsStockConsiderationVestedValue_30ac0a46-218d-45e9-9102-f87fa2ce288d" xlink:href="cpix-20231231.xsd#cpix_CollaborativeArrangementRightsAndObligationsStockConsiderationVestedValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_25c8459b-8849-4a50-82fa-67560b7a4f00" xlink:to="loc_cpix_CollaborativeArrangementRightsAndObligationsStockConsiderationVestedValue_30ac0a46-218d-45e9-9102-f87fa2ce288d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_CollaborativeArrangementRightsAndObligationsMilestonePayment_f0bbdf47-170a-432e-ac7e-7cf7a32be3c7" xlink:href="cpix-20231231.xsd#cpix_CollaborativeArrangementRightsAndObligationsMilestonePayment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_25c8459b-8849-4a50-82fa-67560b7a4f00" xlink:to="loc_cpix_CollaborativeArrangementRightsAndObligationsMilestonePayment_f0bbdf47-170a-432e-ac7e-7cf7a32be3c7" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_CollaborativeArrangementRightsAndObligationsStockConsiderationCancelledAndRefunded_f2635e2c-70fb-4124-bf70-f92e705d732b" xlink:href="cpix-20231231.xsd#cpix_CollaborativeArrangementRightsAndObligationsStockConsiderationCancelledAndRefunded"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_25c8459b-8849-4a50-82fa-67560b7a4f00" xlink:to="loc_cpix_CollaborativeArrangementRightsAndObligationsStockConsiderationCancelledAndRefunded_f2635e2c-70fb-4124-bf70-f92e705d732b" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_CollaborativeArrangementRightsAndObligationsMilestonePaymentCreditDue_7db24ef1-5d4c-468c-9d27-12dcb83d67f1" xlink:href="cpix-20231231.xsd#cpix_CollaborativeArrangementRightsAndObligationsMilestonePaymentCreditDue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_25c8459b-8849-4a50-82fa-67560b7a4f00" xlink:to="loc_cpix_CollaborativeArrangementRightsAndObligationsMilestonePaymentCreditDue_7db24ef1-5d4c-468c-9d27-12dcb83d67f1" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cumberlandpharma.com/role/VibativSancusoandRediTrexProductsChangesInFairValueOfContingentConsiderationLiabilityDetails" xlink:type="simple" xlink:href="cpix-20231231.xsd#VibativSancusoandRediTrexProductsChangesInFairValueOfContingentConsiderationLiabilityDetails"/>
  <link:definitionLink xlink:role="http://www.cumberlandpharma.com/role/VibativSancusoandRediTrexProductsChangesInFairValueOfContingentConsiderationLiabilityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionContingentConsiderationLineItems_407d2519-a11f-4c5e-a604-9e3b5314187f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionContingentConsiderationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionContingentConsiderationTable_f1b9201d-e238-4750-8f89-8a10b55551b3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionContingentConsiderationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionContingentConsiderationLineItems_407d2519-a11f-4c5e-a604-9e3b5314187f" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionContingentConsiderationTable_f1b9201d-e238-4750-8f89-8a10b55551b3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_1f38dcd6-bcd4-4e10-a8bb-9a635dcbeef9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionContingentConsiderationTable_f1b9201d-e238-4750-8f89-8a10b55551b3" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_1f38dcd6-bcd4-4e10-a8bb-9a635dcbeef9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1f38dcd6-bcd4-4e10-a8bb-9a635dcbeef9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_1f38dcd6-bcd4-4e10-a8bb-9a635dcbeef9" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1f38dcd6-bcd4-4e10-a8bb-9a635dcbeef9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_7fa35802-31c7-4191-a0eb-2d7fc1985523" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_1f38dcd6-bcd4-4e10-a8bb-9a635dcbeef9" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_7fa35802-31c7-4191-a0eb-2d7fc1985523" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ProductAssetsAndGlobalRightsVibativMember_5651fdb4-028c-470d-9cf8-4eccd84731e5" xlink:href="cpix-20231231.xsd#cpix_ProductAssetsAndGlobalRightsVibativMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_7fa35802-31c7-4191-a0eb-2d7fc1985523" xlink:to="loc_cpix_ProductAssetsAndGlobalRightsVibativMember_5651fdb4-028c-470d-9cf8-4eccd84731e5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_U.S.ProductAssetRightsSancusoMember_b5a1396c-505a-4363-a974-9bac3696db93" xlink:href="cpix-20231231.xsd#cpix_U.S.ProductAssetRightsSancusoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_7fa35802-31c7-4191-a0eb-2d7fc1985523" xlink:to="loc_cpix_U.S.ProductAssetRightsSancusoMember_b5a1396c-505a-4363-a974-9bac3696db93" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_BusinessCombinationContingentConsiderationLiabilityRollForward_ab99cf3b-d4ee-4f7a-b92f-dd0e6d31554a" xlink:href="cpix-20231231.xsd#cpix_BusinessCombinationContingentConsiderationLiabilityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionContingentConsiderationLineItems_407d2519-a11f-4c5e-a604-9e3b5314187f" xlink:to="loc_cpix_BusinessCombinationContingentConsiderationLiabilityRollForward_ab99cf3b-d4ee-4f7a-b92f-dd0e6d31554a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_39b2ef9c-63e4-4093-b83a-f50bb108dc1c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cpix_BusinessCombinationContingentConsiderationLiabilityRollForward_ab99cf3b-d4ee-4f7a-b92f-dd0e6d31554a" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_39b2ef9c-63e4-4093-b83a-f50bb108dc1c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForRoyalties_84916e31-4a5a-4ce6-916c-6dd62df6cf1a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsForRoyalties"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cpix_BusinessCombinationContingentConsiderationLiabilityRollForward_ab99cf3b-d4ee-4f7a-b92f-dd0e6d31554a" xlink:to="loc_us-gaap_PaymentsForRoyalties_84916e31-4a5a-4ce6-916c-6dd62df6cf1a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_772f70c3-b5dc-444c-a369-f3cb6b947749" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cpix_BusinessCombinationContingentConsiderationLiabilityRollForward_ab99cf3b-d4ee-4f7a-b92f-dd0e6d31554a" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_772f70c3-b5dc-444c-a369-f3cb6b947749" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_BusinessCombinationContingentConsiderationEarnedAndAccruedInOperatingExpenses_b0a30a11-5c41-4e37-8a3e-fc96dd241cb0" xlink:href="cpix-20231231.xsd#cpix_BusinessCombinationContingentConsiderationEarnedAndAccruedInOperatingExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cpix_BusinessCombinationContingentConsiderationLiabilityRollForward_ab99cf3b-d4ee-4f7a-b92f-dd0e6d31554a" xlink:to="loc_cpix_BusinessCombinationContingentConsiderationEarnedAndAccruedInOperatingExpenses_b0a30a11-5c41-4e37-8a3e-fc96dd241cb0" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_c1cee686-4169-4911-aac7-98af55f48362" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cumberlandpharma.com/role/RevenuesScheduleofNetProductRevenuesbyProductDetails" xlink:type="simple" xlink:href="cpix-20231231.xsd#RevenuesScheduleofNetProductRevenuesbyProductDetails"/>
  <link:definitionLink xlink:role="http://www.cumberlandpharma.com/role/RevenuesScheduleofNetProductRevenuesbyProductDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EntityWideInformationRevenueFromExternalCustomerLineItems_16646c11-c8de-4b1a-b6db-2c14a56742e4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EntityWideInformationRevenueFromExternalCustomerLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTable_c0f581a6-641d-4a9e-82b0-d32cb5e9fa14" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EntityWideInformationRevenueFromExternalCustomerLineItems_16646c11-c8de-4b1a-b6db-2c14a56742e4" xlink:to="loc_us-gaap_ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTable_c0f581a6-641d-4a9e-82b0-d32cb5e9fa14" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_5a7cfdfb-2f58-446e-b5b3-896d5025a03b" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTable_c0f581a6-641d-4a9e-82b0-d32cb5e9fa14" xlink:to="loc_srt_ProductOrServiceAxis_5a7cfdfb-2f58-446e-b5b3-896d5025a03b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_5a7cfdfb-2f58-446e-b5b3-896d5025a03b_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_5a7cfdfb-2f58-446e-b5b3-896d5025a03b" xlink:to="loc_srt_ProductsAndServicesDomain_5a7cfdfb-2f58-446e-b5b3-896d5025a03b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_eeeb478b-2e3a-4da2-b7d2-dfd073096ccd" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_5a7cfdfb-2f58-446e-b5b3-896d5025a03b" xlink:to="loc_srt_ProductsAndServicesDomain_eeeb478b-2e3a-4da2-b7d2-dfd073096ccd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductMember_cec093e2-627b-4b8a-9db9-90751d1cb36c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProductMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_eeeb478b-2e3a-4da2-b7d2-dfd073096ccd" xlink:to="loc_us-gaap_ProductMember_cec093e2-627b-4b8a-9db9-90751d1cb36c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ProductKristaloseMember_f8b199c9-ccee-4380-8135-2997c8d8f76d" xlink:href="cpix-20231231.xsd#cpix_ProductKristaloseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductMember_cec093e2-627b-4b8a-9db9-90751d1cb36c" xlink:to="loc_cpix_ProductKristaloseMember_f8b199c9-ccee-4380-8135-2997c8d8f76d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ProductVibativMember_86c2c2c6-dc50-4e9c-90cb-53fa81161e8e" xlink:href="cpix-20231231.xsd#cpix_ProductVibativMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductMember_cec093e2-627b-4b8a-9db9-90751d1cb36c" xlink:to="loc_cpix_ProductVibativMember_86c2c2c6-dc50-4e9c-90cb-53fa81161e8e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ProductSancusoMember_bb4699a4-4475-4f8c-af46-cbd2b16aae57" xlink:href="cpix-20231231.xsd#cpix_ProductSancusoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductMember_cec093e2-627b-4b8a-9db9-90751d1cb36c" xlink:to="loc_cpix_ProductSancusoMember_bb4699a4-4475-4f8c-af46-cbd2b16aae57" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ProductCaldolorMember_d2c2f647-c9bc-4eb6-a350-f400dce4f889" xlink:href="cpix-20231231.xsd#cpix_ProductCaldolorMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductMember_cec093e2-627b-4b8a-9db9-90751d1cb36c" xlink:to="loc_cpix_ProductCaldolorMember_d2c2f647-c9bc-4eb6-a350-f400dce4f889" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ProductAcetadoteMember_0af63aa1-b28a-45eb-ae2b-d6727468bfad" xlink:href="cpix-20231231.xsd#cpix_ProductAcetadoteMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductMember_cec093e2-627b-4b8a-9db9-90751d1cb36c" xlink:to="loc_cpix_ProductAcetadoteMember_0af63aa1-b28a-45eb-ae2b-d6727468bfad" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ProductOmeclamoxPakMember_bc94cd62-4989-4b09-b955-699c78aa04c3" xlink:href="cpix-20231231.xsd#cpix_ProductOmeclamoxPakMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductMember_cec093e2-627b-4b8a-9db9-90751d1cb36c" xlink:to="loc_cpix_ProductOmeclamoxPakMember_bc94cd62-4989-4b09-b955-699c78aa04c3" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ProductVaprisolMember_09acf473-fbe1-4960-9377-a69451b4a98f" xlink:href="cpix-20231231.xsd#cpix_ProductVaprisolMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductMember_cec093e2-627b-4b8a-9db9-90751d1cb36c" xlink:to="loc_cpix_ProductVaprisolMember_09acf473-fbe1-4960-9377-a69451b4a98f" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ProductRediTrexMember_fa3ff71f-84a8-400e-b73b-c0ea0b767db3" xlink:href="cpix-20231231.xsd#cpix_ProductRediTrexMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductMember_cec093e2-627b-4b8a-9db9-90751d1cb36c" xlink:to="loc_cpix_ProductRediTrexMember_fa3ff71f-84a8-400e-b73b-c0ea0b767db3" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_5a70fde5-e0fa-463a-b2b7-864ff883352d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EntityWideInformationRevenueFromExternalCustomerLineItems_16646c11-c8de-4b1a-b6db-2c14a56742e4" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_5a70fde5-e0fa-463a-b2b7-864ff883352d" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cumberlandpharma.com/role/RevenuesNarrativeDetails" xlink:type="simple" xlink:href="cpix-20231231.xsd#RevenuesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.cumberlandpharma.com/role/RevenuesNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_ef17a2f3-5db4-42e2-a717-c4997f6bd2aa" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_a73e9571-2596-4136-9411-1d0f0d1dda5c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_ef17a2f3-5db4-42e2-a717-c4997f6bd2aa" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_a73e9571-2596-4136-9411-1d0f0d1dda5c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_7a9c19b9-7917-4803-a918-a30f8a6f7eda" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_a73e9571-2596-4136-9411-1d0f0d1dda5c" xlink:to="loc_srt_ProductOrServiceAxis_7a9c19b9-7917-4803-a918-a30f8a6f7eda" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_7a9c19b9-7917-4803-a918-a30f8a6f7eda_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_7a9c19b9-7917-4803-a918-a30f8a6f7eda" xlink:to="loc_srt_ProductsAndServicesDomain_7a9c19b9-7917-4803-a918-a30f8a6f7eda_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_890ff90b-1a76-4419-8c9f-082e096a8685" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_7a9c19b9-7917-4803-a918-a30f8a6f7eda" xlink:to="loc_srt_ProductsAndServicesDomain_890ff90b-1a76-4419-8c9f-082e096a8685" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_VibativMember_0f6a3334-4bb8-4e91-aa24-33199904ae83" xlink:href="cpix-20231231.xsd#cpix_VibativMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_890ff90b-1a76-4419-8c9f-082e096a8685" xlink:to="loc_cpix_VibativMember_0f6a3334-4bb8-4e91-aa24-33199904ae83" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrantMember_de588f96-4e7c-4f07-bcd6-f0dbb5a37e2a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GrantMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_890ff90b-1a76-4419-8c9f-082e096a8685" xlink:to="loc_us-gaap_GrantMember_de588f96-4e7c-4f07-bcd6-f0dbb5a37e2a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_e38ac15b-b484-4643-ac62-83b5effcab1c" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_CounterpartyNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_a73e9571-2596-4136-9411-1d0f0d1dda5c" xlink:to="loc_srt_CounterpartyNameAxis_e38ac15b-b484-4643-ac62-83b5effcab1c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_e38ac15b-b484-4643-ac62-83b5effcab1c_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_e38ac15b-b484-4643-ac62-83b5effcab1c" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_e38ac15b-b484-4643-ac62-83b5effcab1c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_9d258138-d5c1-452e-9103-ab45b0274ee6" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_e38ac15b-b484-4643-ac62-83b5effcab1c" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_9d258138-d5c1-452e-9103-ab45b0274ee6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_FederalGrantProgramsMember_c9da1c43-9717-4c64-90bb-c0ff5fda2b96" xlink:href="cpix-20231231.xsd#cpix_FederalGrantProgramsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_9d258138-d5c1-452e-9103-ab45b0274ee6" xlink:to="loc_cpix_FederalGrantProgramsMember_c9da1c43-9717-4c64-90bb-c0ff5fda2b96" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromLegalSettlements_d51758d7-2af2-4707-95f3-b72cb4e916f2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromLegalSettlements"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_ef17a2f3-5db4-42e2-a717-c4997f6bd2aa" xlink:to="loc_us-gaap_ProceedsFromLegalSettlements_d51758d7-2af2-4707-95f3-b72cb4e916f2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ProceedsFromLegalSettlementsMilestonePaymentsReceivableNumberOfPayments_48205fcd-4c62-4457-8803-c280e009d369" xlink:href="cpix-20231231.xsd#cpix_ProceedsFromLegalSettlementsMilestonePaymentsReceivableNumberOfPayments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_ef17a2f3-5db4-42e2-a717-c4997f6bd2aa" xlink:to="loc_cpix_ProceedsFromLegalSettlementsMilestonePaymentsReceivableNumberOfPayments_48205fcd-4c62-4457-8803-c280e009d369" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ProceedsFromLegalSettlementsMilestonePaymentsReceivablePaymentOne_78ab20a2-4e04-4958-aee1-1b4fa4502171" xlink:href="cpix-20231231.xsd#cpix_ProceedsFromLegalSettlementsMilestonePaymentsReceivablePaymentOne"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_ef17a2f3-5db4-42e2-a717-c4997f6bd2aa" xlink:to="loc_cpix_ProceedsFromLegalSettlementsMilestonePaymentsReceivablePaymentOne_78ab20a2-4e04-4958-aee1-1b4fa4502171" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ProceedsFromLegalSettlementsMilestonePaymentsReceivablePaymentTwo_0b3f27b8-7b11-4f1c-a832-6e73a1f15ce3" xlink:href="cpix-20231231.xsd#cpix_ProceedsFromLegalSettlementsMilestonePaymentsReceivablePaymentTwo"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_ef17a2f3-5db4-42e2-a717-c4997f6bd2aa" xlink:to="loc_cpix_ProceedsFromLegalSettlementsMilestonePaymentsReceivablePaymentTwo_0b3f27b8-7b11-4f1c-a832-6e73a1f15ce3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_6770b1d2-7caa-43d4-87fb-d5712b69533c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_ef17a2f3-5db4-42e2-a717-c4997f6bd2aa" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_6770b1d2-7caa-43d4-87fb-d5712b69533c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubleaseIncome_237292da-e822-4469-aade-609a1fb53a01" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SubleaseIncome"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_ef17a2f3-5db4-42e2-a717-c4997f6bd2aa" xlink:to="loc_us-gaap_SubleaseIncome_237292da-e822-4469-aade-609a1fb53a01" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cumberlandpharma.com/role/InventoriesNetScheduleofNonCurrentInventoriesDetails" xlink:type="simple" xlink:href="cpix-20231231.xsd#InventoriesNetScheduleofNonCurrentInventoriesDetails"/>
  <link:definitionLink xlink:role="http://www.cumberlandpharma.com/role/InventoriesNetScheduleofNonCurrentInventoriesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_cpix_InventoryNoncurrentLineItems_97a0165c-f07e-4148-a92b-b575620cff7c" xlink:href="cpix-20231231.xsd#cpix_InventoryNoncurrentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_InventoryNoncurrentTable_e064ab12-01e9-4706-b25f-9ac1970df428" xlink:href="cpix-20231231.xsd#cpix_InventoryNoncurrentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_cpix_InventoryNoncurrentLineItems_97a0165c-f07e-4148-a92b-b575620cff7c" xlink:to="loc_cpix_InventoryNoncurrentTable_e064ab12-01e9-4706-b25f-9ac1970df428" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_085888f7-4b93-4494-8ef6-0ae6d2d7d619" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_cpix_InventoryNoncurrentTable_e064ab12-01e9-4706-b25f-9ac1970df428" xlink:to="loc_srt_ProductOrServiceAxis_085888f7-4b93-4494-8ef6-0ae6d2d7d619" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_085888f7-4b93-4494-8ef6-0ae6d2d7d619_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_085888f7-4b93-4494-8ef6-0ae6d2d7d619" xlink:to="loc_srt_ProductsAndServicesDomain_085888f7-4b93-4494-8ef6-0ae6d2d7d619_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_b81d00e9-4474-4f8c-aaef-242fd24cfb8b" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_085888f7-4b93-4494-8ef6-0ae6d2d7d619" xlink:to="loc_srt_ProductsAndServicesDomain_b81d00e9-4474-4f8c-aaef-242fd24cfb8b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_VibativMember_14f23feb-5f6d-4d87-8ee3-6b303cb260fc" xlink:href="cpix-20231231.xsd#cpix_VibativMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_b81d00e9-4474-4f8c-aaef-242fd24cfb8b" xlink:to="loc_cpix_VibativMember_14f23feb-5f6d-4d87-8ee3-6b303cb260fc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_KristaloseMember_a1943006-2a2f-4f96-a4ea-83cef08d4699" xlink:href="cpix-20231231.xsd#cpix_KristaloseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_b81d00e9-4474-4f8c-aaef-242fd24cfb8b" xlink:to="loc_cpix_KristaloseMember_a1943006-2a2f-4f96-a4ea-83cef08d4699" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_VaprisolMember_f4f1b485-84b8-4d7d-8c25-6dba9f1b6e35" xlink:href="cpix-20231231.xsd#cpix_VaprisolMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_b81d00e9-4474-4f8c-aaef-242fd24cfb8b" xlink:to="loc_cpix_VaprisolMember_f4f1b485-84b8-4d7d-8c25-6dba9f1b6e35" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_CaldolorMember_61894e85-8993-4c16-a8b8-8d4ee7c5a5af" xlink:href="cpix-20231231.xsd#cpix_CaldolorMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_b81d00e9-4474-4f8c-aaef-242fd24cfb8b" xlink:to="loc_cpix_CaldolorMember_61894e85-8993-4c16-a8b8-8d4ee7c5a5af" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_SancusoMember_c065ccf4-9afe-4d73-88b7-dcbf3aab6f8b" xlink:href="cpix-20231231.xsd#cpix_SancusoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_b81d00e9-4474-4f8c-aaef-242fd24cfb8b" xlink:to="loc_cpix_SancusoMember_c065ccf4-9afe-4d73-88b7-dcbf3aab6f8b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_StudyDrugMember_c40cfb63-e28e-4ead-b92e-5e40fc4f5787" xlink:href="cpix-20231231.xsd#cpix_StudyDrugMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_b81d00e9-4474-4f8c-aaef-242fd24cfb8b" xlink:to="loc_cpix_StudyDrugMember_c40cfb63-e28e-4ead-b92e-5e40fc4f5787" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesInventoryAxis_00d05ff2-4f2c-44dd-8df2-0fcd369c6256" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PublicUtilitiesInventoryAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_cpix_InventoryNoncurrentTable_e064ab12-01e9-4706-b25f-9ac1970df428" xlink:to="loc_us-gaap_PublicUtilitiesInventoryAxis_00d05ff2-4f2c-44dd-8df2-0fcd369c6256" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_00d05ff2-4f2c-44dd-8df2-0fcd369c6256_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PublicUtilitiesInventoryTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PublicUtilitiesInventoryAxis_00d05ff2-4f2c-44dd-8df2-0fcd369c6256" xlink:to="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_00d05ff2-4f2c-44dd-8df2-0fcd369c6256_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_dbb45cf9-99a8-4b1d-b658-ba91a8ae43a2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PublicUtilitiesInventoryTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PublicUtilitiesInventoryAxis_00d05ff2-4f2c-44dd-8df2-0fcd369c6256" xlink:to="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_dbb45cf9-99a8-4b1d-b658-ba91a8ae43a2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesInventoryRawMaterialsMember_add9a1aa-0df5-48c4-84ea-f8bc3ce64452" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PublicUtilitiesInventoryRawMaterialsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_dbb45cf9-99a8-4b1d-b658-ba91a8ae43a2" xlink:to="loc_us-gaap_PublicUtilitiesInventoryRawMaterialsMember_add9a1aa-0df5-48c4-84ea-f8bc3ce64452" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_FinishedGoodsMember_037e41fb-cf5f-4bf7-9ed7-d2ba8aef841d" xlink:href="cpix-20231231.xsd#cpix_FinishedGoodsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_dbb45cf9-99a8-4b1d-b658-ba91a8ae43a2" xlink:to="loc_cpix_FinishedGoodsMember_037e41fb-cf5f-4bf7-9ed7-d2ba8aef841d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_OtherProductsMember_a69674b1-1c4c-4d03-9a35-fc0f2b697876" xlink:href="cpix-20231231.xsd#cpix_OtherProductsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_dbb45cf9-99a8-4b1d-b658-ba91a8ae43a2" xlink:to="loc_cpix_OtherProductsMember_a69674b1-1c4c-4d03-9a35-fc0f2b697876" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryNoncurrent_af58bacc-164a-4232-bba4-46c5ca65766f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InventoryNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cpix_InventoryNoncurrentLineItems_97a0165c-f07e-4148-a92b-b575620cff7c" xlink:to="loc_us-gaap_InventoryNoncurrent_af58bacc-164a-4232-bba4-46c5ca65766f" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cumberlandpharma.com/role/InventoriesNetNarrativeDetails" xlink:type="simple" xlink:href="cpix-20231231.xsd#InventoriesNetNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.cumberlandpharma.com/role/InventoriesNetNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryLineItems_6975fbc1-0e0f-4a83-bfe2-ecf05673d01f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InventoryLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryCurrentTable_327ebcb8-c050-40d6-8a48-3e12da76d6b7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InventoryCurrentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_InventoryLineItems_6975fbc1-0e0f-4a83-bfe2-ecf05673d01f" xlink:to="loc_us-gaap_InventoryCurrentTable_327ebcb8-c050-40d6-8a48-3e12da76d6b7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_0fdb7d49-2c0d-4a7f-be75-a1e532c8e7d3" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_InventoryCurrentTable_327ebcb8-c050-40d6-8a48-3e12da76d6b7" xlink:to="loc_srt_ProductOrServiceAxis_0fdb7d49-2c0d-4a7f-be75-a1e532c8e7d3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_0fdb7d49-2c0d-4a7f-be75-a1e532c8e7d3_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_0fdb7d49-2c0d-4a7f-be75-a1e532c8e7d3" xlink:to="loc_srt_ProductsAndServicesDomain_0fdb7d49-2c0d-4a7f-be75-a1e532c8e7d3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_9edd3696-f21e-44b3-b574-b39c0d1e2939" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_0fdb7d49-2c0d-4a7f-be75-a1e532c8e7d3" xlink:to="loc_srt_ProductsAndServicesDomain_9edd3696-f21e-44b3-b574-b39c0d1e2939" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_VibativMember_85c7e71e-46f1-4ddd-9322-038fc509d0c6" xlink:href="cpix-20231231.xsd#cpix_VibativMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_9edd3696-f21e-44b3-b574-b39c0d1e2939" xlink:to="loc_cpix_VibativMember_85c7e71e-46f1-4ddd-9322-038fc509d0c6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesInventoryAxis_4552a7b3-b9f3-425d-be51-09e324458577" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PublicUtilitiesInventoryAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_InventoryCurrentTable_327ebcb8-c050-40d6-8a48-3e12da76d6b7" xlink:to="loc_us-gaap_PublicUtilitiesInventoryAxis_4552a7b3-b9f3-425d-be51-09e324458577" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_4552a7b3-b9f3-425d-be51-09e324458577_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PublicUtilitiesInventoryTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PublicUtilitiesInventoryAxis_4552a7b3-b9f3-425d-be51-09e324458577" xlink:to="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_4552a7b3-b9f3-425d-be51-09e324458577_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_23578f4b-d7e4-46a4-aede-775d8f34d660" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PublicUtilitiesInventoryTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PublicUtilitiesInventoryAxis_4552a7b3-b9f3-425d-be51-09e324458577" xlink:to="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_23578f4b-d7e4-46a4-aede-775d8f34d660" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ActivePharmaceuticalIngredientAPIAndWorkInProgressMember_13dfdd1a-ea0e-4795-a575-215eb73c6604" xlink:href="cpix-20231231.xsd#cpix_ActivePharmaceuticalIngredientAPIAndWorkInProgressMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_23578f4b-d7e4-46a4-aede-775d8f34d660" xlink:to="loc_cpix_ActivePharmaceuticalIngredientAPIAndWorkInProgressMember_13dfdd1a-ea0e-4795-a575-215eb73c6604" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryNoncurrent_67d17ed1-ddf7-4ce7-b959-034c497ec7a1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InventoryNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InventoryLineItems_6975fbc1-0e0f-4a83-bfe2-ecf05673d01f" xlink:to="loc_us-gaap_InventoryNoncurrent_67d17ed1-ddf7-4ce7-b959-034c497ec7a1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryValuationReserves_4fef41a3-1fe1-4407-b91e-503a7c59519d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InventoryValuationReserves"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InventoryLineItems_6975fbc1-0e0f-4a83-bfe2-ecf05673d01f" xlink:to="loc_us-gaap_InventoryValuationReserves_4fef41a3-1fe1-4407-b91e-503a7c59519d" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cumberlandpharma.com/role/PropertyandEquipmentScheduleofPropertyandEquipmentDetails" xlink:type="simple" xlink:href="cpix-20231231.xsd#PropertyandEquipmentScheduleofPropertyandEquipmentDetails"/>
  <link:definitionLink xlink:role="http://www.cumberlandpharma.com/role/PropertyandEquipmentScheduleofPropertyandEquipmentDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_243df088-cd11-4d42-9306-d82d269e0cc2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_d198aa0e-c1be-4385-bfd4-25af7875e620" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_243df088-cd11-4d42-9306-d82d269e0cc2" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_d198aa0e-c1be-4385-bfd4-25af7875e620" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_0a430da3-ac38-428d-bd20-2574231f3d62" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_d198aa0e-c1be-4385-bfd4-25af7875e620" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_0a430da3-ac38-428d-bd20-2574231f3d62" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_0a430da3-ac38-428d-bd20-2574231f3d62_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_0a430da3-ac38-428d-bd20-2574231f3d62" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_0a430da3-ac38-428d-bd20-2574231f3d62_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_4cae1cdc-31c3-4f27-8c6b-6e2f65ff936e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_0a430da3-ac38-428d-bd20-2574231f3d62" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_4cae1cdc-31c3-4f27-8c6b-6e2f65ff936e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComputerEquipmentMember_3edcba75-fd63-44ad-8cf6-7413ec50bee8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ComputerEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_4cae1cdc-31c3-4f27-8c6b-6e2f65ff936e" xlink:to="loc_us-gaap_ComputerEquipmentMember_3edcba75-fd63-44ad-8cf6-7413ec50bee8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OfficeEquipmentMember_5d6a7cee-ee01-4cbe-a532-fdb56ecc178d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OfficeEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_4cae1cdc-31c3-4f27-8c6b-6e2f65ff936e" xlink:to="loc_us-gaap_OfficeEquipmentMember_5d6a7cee-ee01-4cbe-a532-fdb56ecc178d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FurnitureAndFixturesMember_b278793f-2571-43ce-81db-7387cb148438" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FurnitureAndFixturesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_4cae1cdc-31c3-4f27-8c6b-6e2f65ff936e" xlink:to="loc_us-gaap_FurnitureAndFixturesMember_b278793f-2571-43ce-81db-7387cb148438" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseholdImprovementsMember_3160fd8c-5897-484d-95fd-f92cd0367315" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LeaseholdImprovementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_4cae1cdc-31c3-4f27-8c6b-6e2f65ff936e" xlink:to="loc_us-gaap_LeaseholdImprovementsMember_3160fd8c-5897-484d-95fd-f92cd0367315" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_ddb4e70d-a120-4bdb-955c-4f660378c1f1" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_d198aa0e-c1be-4385-bfd4-25af7875e620" xlink:to="loc_srt_RangeAxis_ddb4e70d-a120-4bdb-955c-4f660378c1f1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_ddb4e70d-a120-4bdb-955c-4f660378c1f1_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_ddb4e70d-a120-4bdb-955c-4f660378c1f1" xlink:to="loc_srt_RangeMember_ddb4e70d-a120-4bdb-955c-4f660378c1f1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_e3745dcf-e878-4951-9bfa-bf5173dc6448" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_ddb4e70d-a120-4bdb-955c-4f660378c1f1" xlink:to="loc_srt_RangeMember_e3745dcf-e878-4951-9bfa-bf5173dc6448" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_f3a311c0-cbf3-4933-b271-b2c2b416276a" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_e3745dcf-e878-4951-9bfa-bf5173dc6448" xlink:to="loc_srt_MinimumMember_f3a311c0-cbf3-4933-b271-b2c2b416276a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_e6386b33-0177-4668-89f6-09060b3b1094" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_e3745dcf-e878-4951-9bfa-bf5173dc6448" xlink:to="loc_srt_MaximumMember_e6386b33-0177-4668-89f6-09060b3b1094" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_be666f68-170f-42b4-88a0-d26dfdc6bbf4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_243df088-cd11-4d42-9306-d82d269e0cc2" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_be666f68-170f-42b4-88a0-d26dfdc6bbf4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_c6a4432f-39ab-49ea-a040-c76231b04c1c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_243df088-cd11-4d42-9306-d82d269e0cc2" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_c6a4432f-39ab-49ea-a040-c76231b04c1c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_95366a51-acfb-487c-80d5-1b430ebf3c35" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_243df088-cd11-4d42-9306-d82d269e0cc2" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_95366a51-acfb-487c-80d5-1b430ebf3c35" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_7b6c268c-f8e8-43a0-878a-95dee201a3b0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_243df088-cd11-4d42-9306-d82d269e0cc2" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_7b6c268c-f8e8-43a0-878a-95dee201a3b0" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cumberlandpharma.com/role/IntangibleAssetsandGoodwillScheduleofIntangibleAssetsDetails" xlink:type="simple" xlink:href="cpix-20231231.xsd#IntangibleAssetsandGoodwillScheduleofIntangibleAssetsDetails"/>
  <link:definitionLink xlink:role="http://www.cumberlandpharma.com/role/IntangibleAssetsandGoodwillScheduleofIntangibleAssetsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_cffed7f3-44f4-44e2-9225-9e426007b213" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_6d69f634-8857-4ecb-9729-ea2b69df2d6f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_cffed7f3-44f4-44e2-9225-9e426007b213" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_6d69f634-8857-4ecb-9729-ea2b69df2d6f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_964162c9-fccd-48a8-ab49-b154446ea7f2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_6d69f634-8857-4ecb-9729-ea2b69df2d6f" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_964162c9-fccd-48a8-ab49-b154446ea7f2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_964162c9-fccd-48a8-ab49-b154446ea7f2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_964162c9-fccd-48a8-ab49-b154446ea7f2" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_964162c9-fccd-48a8-ab49-b154446ea7f2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_908bea33-3623-4ad6-8387-f5a2201cfe31" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_964162c9-fccd-48a8-ab49-b154446ea7f2" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_908bea33-3623-4ad6-8387-f5a2201cfe31" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ProductAndLicenseRightsMember_1361a826-055e-462a-9f1c-c3a22b708c77" xlink:href="cpix-20231231.xsd#cpix_ProductAndLicenseRightsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_908bea33-3623-4ad6-8387-f5a2201cfe31" xlink:to="loc_cpix_ProductAndLicenseRightsMember_1361a826-055e-462a-9f1c-c3a22b708c77" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PatentsMember_5a8d7031-883c-4710-af85-ccfe50ac3f0d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PatentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_908bea33-3623-4ad6-8387-f5a2201cfe31" xlink:to="loc_us-gaap_PatentsMember_5a8d7031-883c-4710-af85-ccfe50ac3f0d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TrademarksMember_e47717d8-1c37-4362-b102-a0a4747023fc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TrademarksMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_908bea33-3623-4ad6-8387-f5a2201cfe31" xlink:to="loc_us-gaap_TrademarksMember_e47717d8-1c37-4362-b102-a0a4747023fc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_5ed00638-f98c-4da6-97f1-dfe7443b0ecc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiniteLivedIntangibleAssetsGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_cffed7f3-44f4-44e2-9225-9e426007b213" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_5ed00638-f98c-4da6-97f1-dfe7443b0ecc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_e5361ddb-b6e8-4328-b1d6-4995b7f86eea" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_cffed7f3-44f4-44e2-9225-9e426007b213" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_e5361ddb-b6e8-4328-b1d6-4995b7f86eea" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_f868e6b3-ef55-4c47-8e0c-eb1066624ac3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_cffed7f3-44f4-44e2-9225-9e426007b213" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_f868e6b3-ef55-4c47-8e0c-eb1066624ac3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_ecd86ea9-da67-4ea3-92bd-4a94bfcc5fce" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_cffed7f3-44f4-44e2-9225-9e426007b213" xlink:to="loc_us-gaap_Goodwill_ecd86ea9-da67-4ea3-92bd-4a94bfcc5fce" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cumberlandpharma.com/role/IntangibleAssetsandGoodwillNarrativeDetails" xlink:type="simple" xlink:href="cpix-20231231.xsd#IntangibleAssetsandGoodwillNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.cumberlandpharma.com/role/IntangibleAssetsandGoodwillNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_9ed88d9c-3756-46af-9b4a-418a25b325d5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_24cda440-9c7c-4155-b615-63eafd5cea4b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_9ed88d9c-3756-46af-9b4a-418a25b325d5" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_24cda440-9c7c-4155-b615-63eafd5cea4b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_171d3b88-05bc-4728-983c-c343997e51d0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_24cda440-9c7c-4155-b615-63eafd5cea4b" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_171d3b88-05bc-4728-983c-c343997e51d0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_171d3b88-05bc-4728-983c-c343997e51d0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_171d3b88-05bc-4728-983c-c343997e51d0" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_171d3b88-05bc-4728-983c-c343997e51d0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_71cce40d-5425-47bd-acac-f07374ebf8e5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_171d3b88-05bc-4728-983c-c343997e51d0" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_71cce40d-5425-47bd-acac-f07374ebf8e5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PatentsMember_1e04cb14-05e7-4612-9a14-b834db1810ac" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PatentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_71cce40d-5425-47bd-acac-f07374ebf8e5" xlink:to="loc_us-gaap_PatentsMember_1e04cb14-05e7-4612-9a14-b834db1810ac" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireIntangibleAssets_dd812d5b-278b-4218-9272-605231191c36" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsToAcquireIntangibleAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_9ed88d9c-3756-46af-9b4a-418a25b325d5" xlink:to="loc_us-gaap_PaymentsToAcquireIntangibleAssets_dd812d5b-278b-4218-9272-605231191c36" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cumberlandpharma.com/role/DebtDetails" xlink:type="simple" xlink:href="cpix-20231231.xsd#DebtDetails"/>
  <link:definitionLink xlink:role="http://www.cumberlandpharma.com/role/DebtDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityLineItems_4eb69cfb-bafb-4870-83f3-7b4e7cd498a8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityTable_1de68344-e696-4e00-afcc-035d7486e576" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_4eb69cfb-bafb-4870-83f3-7b4e7cd498a8" xlink:to="loc_us-gaap_LineOfCreditFacilityTable_1de68344-e696-4e00-afcc-035d7486e576" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_7c5e1a66-3357-4829-aa2f-2cb1d76cf195" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_1de68344-e696-4e00-afcc-035d7486e576" xlink:to="loc_us-gaap_CreditFacilityAxis_7c5e1a66-3357-4829-aa2f-2cb1d76cf195" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_7c5e1a66-3357-4829-aa2f-2cb1d76cf195_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_7c5e1a66-3357-4829-aa2f-2cb1d76cf195" xlink:to="loc_us-gaap_CreditFacilityDomain_7c5e1a66-3357-4829-aa2f-2cb1d76cf195_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_0a7028e4-819b-4847-b11b-106d044b1e3f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_7c5e1a66-3357-4829-aa2f-2cb1d76cf195" xlink:to="loc_us-gaap_CreditFacilityDomain_0a7028e4-819b-4847-b11b-106d044b1e3f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_032045f9-d069-4cf5-8a09-9a81ff4f77e4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_0a7028e4-819b-4847-b11b-106d044b1e3f" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_032045f9-d069-4cf5-8a09-9a81ff4f77e4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_b1bf2cf0-092a-4b17-b41f-1fb7d75ac5e5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_1de68344-e696-4e00-afcc-035d7486e576" xlink:to="loc_us-gaap_DebtInstrumentAxis_b1bf2cf0-092a-4b17-b41f-1fb7d75ac5e5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_b1bf2cf0-092a-4b17-b41f-1fb7d75ac5e5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_b1bf2cf0-092a-4b17-b41f-1fb7d75ac5e5" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_b1bf2cf0-092a-4b17-b41f-1fb7d75ac5e5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_cd9151b2-9da0-45f7-816f-9a36e9726636" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_b1bf2cf0-092a-4b17-b41f-1fb7d75ac5e5" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_cd9151b2-9da0-45f7-816f-9a36e9726636" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_59a3bbe3-d924-4d56-89b4-3146308c6d2a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_cd9151b2-9da0-45f7-816f-9a36e9726636" xlink:to="loc_us-gaap_LineOfCreditMember_59a3bbe3-d924-4d56-89b4-3146308c6d2a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityAxis_7df9ddc4-7d96-4f11-9192-570b6fe2d01d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_1de68344-e696-4e00-afcc-035d7486e576" xlink:to="loc_us-gaap_LineOfCreditFacilityAxis_7df9ddc4-7d96-4f11-9192-570b6fe2d01d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityLenderDomain_7df9ddc4-7d96-4f11-9192-570b6fe2d01d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityLenderDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LineOfCreditFacilityAxis_7df9ddc4-7d96-4f11-9192-570b6fe2d01d" xlink:to="loc_us-gaap_LineOfCreditFacilityLenderDomain_7df9ddc4-7d96-4f11-9192-570b6fe2d01d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityLenderDomain_ed49afd9-3580-4fcf-94e7-b1a3bce483d1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityLenderDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LineOfCreditFacilityAxis_7df9ddc4-7d96-4f11-9192-570b6fe2d01d" xlink:to="loc_us-gaap_LineOfCreditFacilityLenderDomain_ed49afd9-3580-4fcf-94e7-b1a3bce483d1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_PinnacleBankMember_d1f0a75c-b5be-422d-a715-cf3cf64fda76" xlink:href="cpix-20231231.xsd#cpix_PinnacleBankMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLenderDomain_ed49afd9-3580-4fcf-94e7-b1a3bce483d1" xlink:to="loc_cpix_PinnacleBankMember_d1f0a75c-b5be-422d-a715-cf3cf64fda76" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_2d7fa6f3-4727-4364-8659-3edd1e67ae44" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_1de68344-e696-4e00-afcc-035d7486e576" xlink:to="loc_srt_RangeAxis_2d7fa6f3-4727-4364-8659-3edd1e67ae44" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_2d7fa6f3-4727-4364-8659-3edd1e67ae44_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_2d7fa6f3-4727-4364-8659-3edd1e67ae44" xlink:to="loc_srt_RangeMember_2d7fa6f3-4727-4364-8659-3edd1e67ae44_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_65b87a4e-0a23-44a5-a99e-675b04dbf9d8" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_2d7fa6f3-4727-4364-8659-3edd1e67ae44" xlink:to="loc_srt_RangeMember_65b87a4e-0a23-44a5-a99e-675b04dbf9d8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_c48a2079-7fe0-46ec-b63f-5cb004c7763f" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_65b87a4e-0a23-44a5-a99e-675b04dbf9d8" xlink:to="loc_srt_MaximumMember_c48a2079-7fe0-46ec-b63f-5cb004c7763f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateAxis_55194cb0-d52f-4514-986f-8bfd86223ba8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_VariableRateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_1de68344-e696-4e00-afcc-035d7486e576" xlink:to="loc_us-gaap_VariableRateAxis_55194cb0-d52f-4514-986f-8bfd86223ba8" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_55194cb0-d52f-4514-986f-8bfd86223ba8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_55194cb0-d52f-4514-986f-8bfd86223ba8" xlink:to="loc_us-gaap_VariableRateDomain_55194cb0-d52f-4514-986f-8bfd86223ba8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_703a7cd1-70df-4b74-9d0b-87bfce24a76a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_55194cb0-d52f-4514-986f-8bfd86223ba8" xlink:to="loc_us-gaap_VariableRateDomain_703a7cd1-70df-4b74-9d0b-87bfce24a76a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember_710d7dc2-6499-4bc2-8257-79f4f98411ec" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_703a7cd1-70df-4b74-9d0b-87bfce24a76a" xlink:to="loc_us-gaap_SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember_710d7dc2-6499-4bc2-8257-79f4f98411ec" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_7a8369d5-4237-49a8-805f-314b710a92bb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_4eb69cfb-bafb-4870-83f3-7b4e7cd498a8" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_7a8369d5-4237-49a8-805f-314b710a92bb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_LineOfCreditFacilityAdditionalBorrowingCapacity_04d4e97b-bca0-467c-8bfe-61f527646b15" xlink:href="cpix-20231231.xsd#cpix_LineOfCreditFacilityAdditionalBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_4eb69cfb-bafb-4870-83f3-7b4e7cd498a8" xlink:to="loc_cpix_LineOfCreditFacilityAdditionalBorrowingCapacity_04d4e97b-bca0-467c-8bfe-61f527646b15" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityExpirationPeriod_4bc41295-b3ac-4f5a-b842-3aff6ed1f870" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityExpirationPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_4eb69cfb-bafb-4870-83f3-7b4e7cd498a8" xlink:to="loc_us-gaap_LineOfCreditFacilityExpirationPeriod_4bc41295-b3ac-4f5a-b842-3aff6ed1f870" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_a2cef141-b411-4685-87a5-ca14aa51e286" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_4eb69cfb-bafb-4870-83f3-7b4e7cd498a8" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_a2cef141-b411-4685-87a5-ca14aa51e286" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermLineOfCredit_006ef66b-9d58-4c17-96df-f7b66486c85b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermLineOfCredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_4eb69cfb-bafb-4870-83f3-7b4e7cd498a8" xlink:to="loc_us-gaap_LongTermLineOfCredit_006ef66b-9d58-4c17-96df-f7b66486c85b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_96aa9683-6c94-4f82-9b1e-c0890dd2a497" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_4eb69cfb-bafb-4870-83f3-7b4e7cd498a8" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_96aa9683-6c94-4f82-9b1e-c0890dd2a497" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cumberlandpharma.com/role/ShareholdersEquityDetails" xlink:type="simple" xlink:href="cpix-20231231.xsd#ShareholdersEquityDetails"/>
  <link:definitionLink xlink:role="http://www.cumberlandpharma.com/role/ShareholdersEquityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems_14ad4998-0e9c-4287-a220-1fa7c30e2eac" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_9719192b-f9c7-440a-94c6-ff4e98ff7d6b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfStockByClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_14ad4998-0e9c-4287-a220-1fa7c30e2eac" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_9719192b-f9c7-440a-94c6-ff4e98ff7d6b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_e764330d-1b82-405c-8cbd-2bb21b972c83" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_9719192b-f9c7-440a-94c6-ff4e98ff7d6b" xlink:to="loc_us-gaap_StatementClassOfStockAxis_e764330d-1b82-405c-8cbd-2bb21b972c83" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_e764330d-1b82-405c-8cbd-2bb21b972c83_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_e764330d-1b82-405c-8cbd-2bb21b972c83" xlink:to="loc_us-gaap_ClassOfStockDomain_e764330d-1b82-405c-8cbd-2bb21b972c83_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_da914f78-dc43-4b6f-b0f3-ecca2954c413" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_e764330d-1b82-405c-8cbd-2bb21b972c83" xlink:to="loc_us-gaap_ClassOfStockDomain_da914f78-dc43-4b6f-b0f3-ecca2954c413" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_9177634d-ae0f-46bd-9ea0-4129766757f4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_da914f78-dc43-4b6f-b0f3-ecca2954c413" xlink:to="loc_us-gaap_CommonStockMember_9177634d-ae0f-46bd-9ea0-4129766757f4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_74401797-0e4f-4493-aa1f-602a74c20126" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_9719192b-f9c7-440a-94c6-ff4e98ff7d6b" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_74401797-0e4f-4493-aa1f-602a74c20126" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_74401797-0e4f-4493-aa1f-602a74c20126_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_74401797-0e4f-4493-aa1f-602a74c20126" xlink:to="loc_us-gaap_EquityComponentDomain_74401797-0e4f-4493-aa1f-602a74c20126_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_9ea832a8-1842-4731-9099-82f945559c98" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_74401797-0e4f-4493-aa1f-602a74c20126" xlink:to="loc_us-gaap_EquityComponentDomain_9ea832a8-1842-4731-9099-82f945559c98" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_00841bab-78f7-4650-a6b7-8481730024ea" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_9ea832a8-1842-4731-9099-82f945559c98" xlink:to="loc_us-gaap_CommonStockMember_00841bab-78f7-4650-a6b7-8481730024ea" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockTransactionDate_45b0dfd8-d053-49b4-b307-b60d54301600" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SaleOfStockTransactionDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_14ad4998-0e9c-4287-a220-1fa7c30e2eac" xlink:to="loc_us-gaap_SaleOfStockTransactionDate_45b0dfd8-d053-49b4-b307-b60d54301600" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_a23f3925-3bb7-49c2-8487-268f64cf32ca" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_14ad4998-0e9c-4287-a220-1fa7c30e2eac" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_a23f3925-3bb7-49c2-8487-268f64cf32ca" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_StockIssuedDuringPeriodPricePerShareNewIssues_c00b78ba-fa3c-4d15-93aa-9a3e04d0c861" xlink:href="cpix-20231231.xsd#cpix_StockIssuedDuringPeriodPricePerShareNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_14ad4998-0e9c-4287-a220-1fa7c30e2eac" xlink:to="loc_cpix_StockIssuedDuringPeriodPricePerShareNewIssues_c00b78ba-fa3c-4d15-93aa-9a3e04d0c861" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_StockIssuedDuringPeriodGrossProceedsFromInitialPublicOffering_7c57f8ac-a821-4c6b-8bb4-9073a2f667ce" xlink:href="cpix-20231231.xsd#cpix_StockIssuedDuringPeriodGrossProceedsFromInitialPublicOffering"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_14ad4998-0e9c-4287-a220-1fa7c30e2eac" xlink:to="loc_cpix_StockIssuedDuringPeriodGrossProceedsFromInitialPublicOffering_7c57f8ac-a821-4c6b-8bb4-9073a2f667ce" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_StockIssuedDuringPeriodNewSharesUnderwritingDiscounts_a5cd235d-9c5c-479d-8730-0f094fb591f7" xlink:href="cpix-20231231.xsd#cpix_StockIssuedDuringPeriodNewSharesUnderwritingDiscounts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_14ad4998-0e9c-4287-a220-1fa7c30e2eac" xlink:to="loc_cpix_StockIssuedDuringPeriodNewSharesUnderwritingDiscounts_a5cd235d-9c5c-479d-8730-0f094fb591f7" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfStockIssuanceCosts_39985b50-36be-41ae-bab4-28217dc5492c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsOfStockIssuanceCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_14ad4998-0e9c-4287-a220-1fa7c30e2eac" xlink:to="loc_us-gaap_PaymentsOfStockIssuanceCosts_39985b50-36be-41ae-bab4-28217dc5492c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceInitialPublicOffering_f0bc3d75-4e33-4b26-95a0-bde04ffab3bf" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromIssuanceInitialPublicOffering"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_14ad4998-0e9c-4287-a220-1fa7c30e2eac" xlink:to="loc_us-gaap_ProceedsFromIssuanceInitialPublicOffering_f0bc3d75-4e33-4b26-95a0-bde04ffab3bf" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesAuthorized_ee656809-ca76-4ce2-89b7-e8088292e309" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_14ad4998-0e9c-4287-a220-1fa7c30e2eac" xlink:to="loc_us-gaap_PreferredStockSharesAuthorized_ee656809-ca76-4ce2-89b7-e8088292e309" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesOutstanding_7e530bd2-b32a-425e-9be2-83525d75d37b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_14ad4998-0e9c-4287-a220-1fa7c30e2eac" xlink:to="loc_us-gaap_PreferredStockSharesOutstanding_7e530bd2-b32a-425e-9be2-83525d75d37b" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_39e7d8cd-9450-40a5-b465-fbab667a6570" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_14ad4998-0e9c-4287-a220-1fa7c30e2eac" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_39e7d8cd-9450-40a5-b465-fbab667a6570" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchaseProgramAuthorizedAmount1_bf7e530d-eabc-4a8d-948f-7005b29f8ed4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockRepurchaseProgramAuthorizedAmount1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_14ad4998-0e9c-4287-a220-1fa7c30e2eac" xlink:to="loc_us-gaap_StockRepurchaseProgramAuthorizedAmount1_bf7e530d-eabc-4a8d-948f-7005b29f8ed4" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodShares_5001fb0c-c4e2-4d6b-811e-20dc5da3d56a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockRepurchasedDuringPeriodShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_14ad4998-0e9c-4287-a220-1fa7c30e2eac" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodShares_5001fb0c-c4e2-4d6b-811e-20dc5da3d56a" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodValue_41b2fcd8-0305-47af-be92-a56ddf86d540" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockRepurchasedDuringPeriodValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_14ad4998-0e9c-4287-a220-1fa7c30e2eac" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodValue_41b2fcd8-0305-47af-be92-a56ddf86d540" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_b0fe270e-cb99-4831-8b39-2f21223b1ff7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_14ad4998-0e9c-4287-a220-1fa7c30e2eac" xlink:to="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_b0fe270e-cb99-4831-8b39-2f21223b1ff7" xlink:type="arc" order="13"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cumberlandpharma.com/role/IncomeTaxesScheduleofNetOperatingLossCarryforwardsDetails" xlink:type="simple" xlink:href="cpix-20231231.xsd#IncomeTaxesScheduleofNetOperatingLossCarryforwardsDetails"/>
  <link:definitionLink xlink:role="http://www.cumberlandpharma.com/role/IncomeTaxesScheduleofNetOperatingLossCarryforwardsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLossCarryforwardsLineItems_4bc0f6a2-4878-4708-80fa-c519e32d2e24" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLossCarryforwardsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLossCarryforwardsTable_cc9a9969-1bf9-4c20-9a87-6c91266b4134" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLossCarryforwardsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_4bc0f6a2-4878-4708-80fa-c519e32d2e24" xlink:to="loc_us-gaap_OperatingLossCarryforwardsTable_cc9a9969-1bf9-4c20-9a87-6c91266b4134" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ExpirationTimePeriodAxis_ea8db3f5-63b7-49c4-b4b0-9579f26ffef3" xlink:href="cpix-20231231.xsd#cpix_ExpirationTimePeriodAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_OperatingLossCarryforwardsTable_cc9a9969-1bf9-4c20-9a87-6c91266b4134" xlink:to="loc_cpix_ExpirationTimePeriodAxis_ea8db3f5-63b7-49c4-b4b0-9579f26ffef3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ExpirationTimePeriodDomain_ea8db3f5-63b7-49c4-b4b0-9579f26ffef3_default" xlink:href="cpix-20231231.xsd#cpix_ExpirationTimePeriodDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_cpix_ExpirationTimePeriodAxis_ea8db3f5-63b7-49c4-b4b0-9579f26ffef3" xlink:to="loc_cpix_ExpirationTimePeriodDomain_ea8db3f5-63b7-49c4-b4b0-9579f26ffef3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ExpirationTimePeriodDomain_45784715-3a54-42cf-bc97-27da1698f0dc" xlink:href="cpix-20231231.xsd#cpix_ExpirationTimePeriodDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_cpix_ExpirationTimePeriodAxis_ea8db3f5-63b7-49c4-b4b0-9579f26ffef3" xlink:to="loc_cpix_ExpirationTimePeriodDomain_45784715-3a54-42cf-bc97-27da1698f0dc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ExpirationTermOneMember_59c9a518-72c2-414c-baa9-ce48633ff12b" xlink:href="cpix-20231231.xsd#cpix_ExpirationTermOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cpix_ExpirationTimePeriodDomain_45784715-3a54-42cf-bc97-27da1698f0dc" xlink:to="loc_cpix_ExpirationTermOneMember_59c9a518-72c2-414c-baa9-ce48633ff12b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ExpirationTermTwoMember_a1931c70-490a-41fe-9f6a-d17f9d539ef8" xlink:href="cpix-20231231.xsd#cpix_ExpirationTermTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cpix_ExpirationTimePeriodDomain_45784715-3a54-42cf-bc97-27da1698f0dc" xlink:to="loc_cpix_ExpirationTermTwoMember_a1931c70-490a-41fe-9f6a-d17f9d539ef8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_IndefiniteMember_319b71b9-e97c-42bb-a2fb-0afdc9aca126" xlink:href="cpix-20231231.xsd#cpix_IndefiniteMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cpix_ExpirationTimePeriodDomain_45784715-3a54-42cf-bc97-27da1698f0dc" xlink:to="loc_cpix_IndefiniteMember_319b71b9-e97c-42bb-a2fb-0afdc9aca126" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityAxis_237d6d29-9bb7-47a2-85e9-7d8e16d58643" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeTaxAuthorityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_OperatingLossCarryforwardsTable_cc9a9969-1bf9-4c20-9a87-6c91266b4134" xlink:to="loc_us-gaap_IncomeTaxAuthorityAxis_237d6d29-9bb7-47a2-85e9-7d8e16d58643" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_237d6d29-9bb7-47a2-85e9-7d8e16d58643_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_237d6d29-9bb7-47a2-85e9-7d8e16d58643" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_237d6d29-9bb7-47a2-85e9-7d8e16d58643_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_34f18908-8df6-42e5-bbae-1b1c82338a9c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_237d6d29-9bb7-47a2-85e9-7d8e16d58643" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_34f18908-8df6-42e5-bbae-1b1c82338a9c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InternalRevenueServiceIRSMember_88129cd5-6524-4a6f-8efa-52b95f9390b9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InternalRevenueServiceIRSMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_34f18908-8df6-42e5-bbae-1b1c82338a9c" xlink:to="loc_us-gaap_InternalRevenueServiceIRSMember_88129cd5-6524-4a6f-8efa-52b95f9390b9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StateAndLocalJurisdictionMember_486ddc27-a4df-4bfc-89b6-8c60a6fcf2e4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StateAndLocalJurisdictionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_34f18908-8df6-42e5-bbae-1b1c82338a9c" xlink:to="loc_us-gaap_StateAndLocalJurisdictionMember_486ddc27-a4df-4bfc-89b6-8c60a6fcf2e4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLossCarryforwards_061eab7e-f44b-4f55-ac1d-2297b298c739" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLossCarryforwards"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_4bc0f6a2-4878-4708-80fa-c519e32d2e24" xlink:to="loc_us-gaap_OperatingLossCarryforwards_061eab7e-f44b-4f55-ac1d-2297b298c739" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cumberlandpharma.com/role/IncomeTaxesScheduleOfTaxCreditCarryforwardsDetails" xlink:type="simple" xlink:href="cpix-20231231.xsd#IncomeTaxesScheduleOfTaxCreditCarryforwardsDetails"/>
  <link:definitionLink xlink:role="http://www.cumberlandpharma.com/role/IncomeTaxesScheduleOfTaxCreditCarryforwardsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxCreditCarryforwardLineItems_f3f02b9f-91c1-41a6-8b91-12c37e91564b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TaxCreditCarryforwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxCreditCarryforwardTable_619533b6-8838-48b2-9c2b-0f23cb3f49da" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TaxCreditCarryforwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_TaxCreditCarryforwardLineItems_f3f02b9f-91c1-41a6-8b91-12c37e91564b" xlink:to="loc_us-gaap_TaxCreditCarryforwardTable_619533b6-8838-48b2-9c2b-0f23cb3f49da" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ExpirationTimePeriodAxis_46cbccde-7bc3-4eef-bdc9-25db163ee0cd" xlink:href="cpix-20231231.xsd#cpix_ExpirationTimePeriodAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_TaxCreditCarryforwardTable_619533b6-8838-48b2-9c2b-0f23cb3f49da" xlink:to="loc_cpix_ExpirationTimePeriodAxis_46cbccde-7bc3-4eef-bdc9-25db163ee0cd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ExpirationTimePeriodDomain_46cbccde-7bc3-4eef-bdc9-25db163ee0cd_default" xlink:href="cpix-20231231.xsd#cpix_ExpirationTimePeriodDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_cpix_ExpirationTimePeriodAxis_46cbccde-7bc3-4eef-bdc9-25db163ee0cd" xlink:to="loc_cpix_ExpirationTimePeriodDomain_46cbccde-7bc3-4eef-bdc9-25db163ee0cd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ExpirationTimePeriodDomain_10bbd2dc-b2fa-4f0d-88ff-2f6809af3cd4" xlink:href="cpix-20231231.xsd#cpix_ExpirationTimePeriodDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_cpix_ExpirationTimePeriodAxis_46cbccde-7bc3-4eef-bdc9-25db163ee0cd" xlink:to="loc_cpix_ExpirationTimePeriodDomain_10bbd2dc-b2fa-4f0d-88ff-2f6809af3cd4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ExpirationTermOneMember_b6b2a491-241a-4971-abe4-d3aa10681802" xlink:href="cpix-20231231.xsd#cpix_ExpirationTermOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cpix_ExpirationTimePeriodDomain_10bbd2dc-b2fa-4f0d-88ff-2f6809af3cd4" xlink:to="loc_cpix_ExpirationTermOneMember_b6b2a491-241a-4971-abe4-d3aa10681802" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ExpirationTermTwoMember_b93d4faf-2747-4c61-8bca-47a28b6359a6" xlink:href="cpix-20231231.xsd#cpix_ExpirationTermTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cpix_ExpirationTimePeriodDomain_10bbd2dc-b2fa-4f0d-88ff-2f6809af3cd4" xlink:to="loc_cpix_ExpirationTermTwoMember_b93d4faf-2747-4c61-8bca-47a28b6359a6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityAxis_6c48e3cd-ba22-4eb3-b749-93938cf4bde6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeTaxAuthorityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_TaxCreditCarryforwardTable_619533b6-8838-48b2-9c2b-0f23cb3f49da" xlink:to="loc_us-gaap_IncomeTaxAuthorityAxis_6c48e3cd-ba22-4eb3-b749-93938cf4bde6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_6c48e3cd-ba22-4eb3-b749-93938cf4bde6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_6c48e3cd-ba22-4eb3-b749-93938cf4bde6" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_6c48e3cd-ba22-4eb3-b749-93938cf4bde6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_6cf9642b-f330-49ca-be38-5699a7ad03cc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_6c48e3cd-ba22-4eb3-b749-93938cf4bde6" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_6cf9642b-f330-49ca-be38-5699a7ad03cc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_FederalAndStateMember_ba667943-a5d4-43a7-9b70-d2b670766217" xlink:href="cpix-20231231.xsd#cpix_FederalAndStateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_6cf9642b-f330-49ca-be38-5699a7ad03cc" xlink:to="loc_cpix_FederalAndStateMember_ba667943-a5d4-43a7-9b70-d2b670766217" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxCreditCarryforwardAmount_094d9475-47b8-42cc-a0ed-28a1db4619d3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TaxCreditCarryforwardAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxCreditCarryforwardLineItems_f3f02b9f-91c1-41a6-8b91-12c37e91564b" xlink:to="loc_us-gaap_TaxCreditCarryforwardAmount_094d9475-47b8-42cc-a0ed-28a1db4619d3" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cumberlandpharma.com/role/StockBasedCompensationPlansNarrativeDetails" xlink:type="simple" xlink:href="cpix-20231231.xsd#StockBasedCompensationPlansNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.cumberlandpharma.com/role/StockBasedCompensationPlansNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3b882f42-843d-434f-ace0-fc17c99a22df" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_93b8e394-7cb9-4f0f-a92d-ab179744f0bb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3b882f42-843d-434f-ace0-fc17c99a22df" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_93b8e394-7cb9-4f0f-a92d-ab179744f0bb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_936d7580-e922-4e8f-bf66-0967b46a0916" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_93b8e394-7cb9-4f0f-a92d-ab179744f0bb" xlink:to="loc_us-gaap_PlanNameAxis_936d7580-e922-4e8f-bf66-0967b46a0916" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_936d7580-e922-4e8f-bf66-0967b46a0916_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_936d7580-e922-4e8f-bf66-0967b46a0916" xlink:to="loc_us-gaap_PlanNameDomain_936d7580-e922-4e8f-bf66-0967b46a0916_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_ac4a2255-9f65-47be-96a3-2ffcc0900dee" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_936d7580-e922-4e8f-bf66-0967b46a0916" xlink:to="loc_us-gaap_PlanNameDomain_ac4a2255-9f65-47be-96a3-2ffcc0900dee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_LongTermIncentiveCompensationPlan2007Member_2bfa43e2-dab6-44b4-af42-ece081086d83" xlink:href="cpix-20231231.xsd#cpix_LongTermIncentiveCompensationPlan2007Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_ac4a2255-9f65-47be-96a3-2ffcc0900dee" xlink:to="loc_cpix_LongTermIncentiveCompensationPlan2007Member_2bfa43e2-dab6-44b4-af42-ece081086d83" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_DirectorsIncentivePlan2007Member_b90b6e63-3f72-4430-bdcb-3f153dfc12e0" xlink:href="cpix-20231231.xsd#cpix_DirectorsIncentivePlan2007Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_ac4a2255-9f65-47be-96a3-2ffcc0900dee" xlink:to="loc_cpix_DirectorsIncentivePlan2007Member_b90b6e63-3f72-4430-bdcb-3f153dfc12e0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_TitleOfIndividualAxis_db0b81a5-ad9e-475a-8121-0df676aedb2b" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_TitleOfIndividualAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_93b8e394-7cb9-4f0f-a92d-ab179744f0bb" xlink:to="loc_srt_TitleOfIndividualAxis_db0b81a5-ad9e-475a-8121-0df676aedb2b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_db0b81a5-ad9e-475a-8121-0df676aedb2b_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_TitleOfIndividualAxis_db0b81a5-ad9e-475a-8121-0df676aedb2b" xlink:to="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_db0b81a5-ad9e-475a-8121-0df676aedb2b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_f5a2b2db-9d0d-4076-b6bd-52bfd0f5019b" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_TitleOfIndividualAxis_db0b81a5-ad9e-475a-8121-0df676aedb2b" xlink:to="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_f5a2b2db-9d0d-4076-b6bd-52bfd0f5019b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_NonprincipalOwnerMember_90f5ae73-57c6-4b55-84b9-dc571a4408aa" xlink:href="cpix-20231231.xsd#cpix_NonprincipalOwnerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_f5a2b2db-9d0d-4076-b6bd-52bfd0f5019b" xlink:to="loc_cpix_NonprincipalOwnerMember_90f5ae73-57c6-4b55-84b9-dc571a4408aa" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrincipalOwnerMember_6c2e8a7c-c2ec-4b25-93f4-be80cd125240" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PrincipalOwnerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_f5a2b2db-9d0d-4076-b6bd-52bfd0f5019b" xlink:to="loc_us-gaap_PrincipalOwnerMember_6c2e8a7c-c2ec-4b25-93f4-be80cd125240" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_DirectorMember_99895dc3-476a-4db9-b059-e1e5602de254" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_DirectorMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_f5a2b2db-9d0d-4076-b6bd-52bfd0f5019b" xlink:to="loc_srt_DirectorMember_99895dc3-476a-4db9-b059-e1e5602de254" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_e3134829-e3a0-4e00-9cec-42b04ad3d3f6" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_93b8e394-7cb9-4f0f-a92d-ab179744f0bb" xlink:to="loc_srt_RangeAxis_e3134829-e3a0-4e00-9cec-42b04ad3d3f6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_e3134829-e3a0-4e00-9cec-42b04ad3d3f6_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_e3134829-e3a0-4e00-9cec-42b04ad3d3f6" xlink:to="loc_srt_RangeMember_e3134829-e3a0-4e00-9cec-42b04ad3d3f6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_f70f29ca-6029-4d8d-8f65-059eac249350" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_e3134829-e3a0-4e00-9cec-42b04ad3d3f6" xlink:to="loc_srt_RangeMember_f70f29ca-6029-4d8d-8f65-059eac249350" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_c1e4dd4e-c5f8-4706-91f8-b9121a792ed9" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_f70f29ca-6029-4d8d-8f65-059eac249350" xlink:to="loc_srt_MaximumMember_c1e4dd4e-c5f8-4706-91f8-b9121a792ed9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_0608811f-178b-4037-8407-d2d0424bb5d8" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_f70f29ca-6029-4d8d-8f65-059eac249350" xlink:to="loc_srt_MinimumMember_0608811f-178b-4037-8407-d2d0424bb5d8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_ad7d73eb-352e-4368-9745-c7359e9b5179" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_93b8e394-7cb9-4f0f-a92d-ab179744f0bb" xlink:to="loc_us-gaap_AwardTypeAxis_ad7d73eb-352e-4368-9745-c7359e9b5179" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_ad7d73eb-352e-4368-9745-c7359e9b5179_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_ad7d73eb-352e-4368-9745-c7359e9b5179" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_ad7d73eb-352e-4368-9745-c7359e9b5179_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_79dff463-f21b-4cf8-928d-6729fa5db2fb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_ad7d73eb-352e-4368-9745-c7359e9b5179" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_79dff463-f21b-4cf8-928d-6729fa5db2fb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_a8a8bf41-a58d-4a3e-809b-61f51b15df37" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_79dff463-f21b-4cf8-928d-6729fa5db2fb" xlink:to="loc_us-gaap_EmployeeStockOptionMember_a8a8bf41-a58d-4a3e-809b-61f51b15df37" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_02b69354-f460-4dc7-b072-8ecb3d364d18" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_79dff463-f21b-4cf8-928d-6729fa5db2fb" xlink:to="loc_us-gaap_RestrictedStockMember_02b69354-f460-4dc7-b072-8ecb3d364d18" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPlansAvailableForFutureGrants_84400b2b-6bdd-4885-8b9d-9f6485c7a42a" xlink:href="cpix-20231231.xsd#cpix_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPlansAvailableForFutureGrants"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3b882f42-843d-434f-ace0-fc17c99a22df" xlink:to="loc_cpix_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPlansAvailableForFutureGrants_84400b2b-6bdd-4885-8b9d-9f6485c7a42a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_740442dd-84d3-4312-8efa-4b3dc1512223" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3b882f42-843d-434f-ace0-fc17c99a22df" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_740442dd-84d3-4312-8efa-4b3dc1512223" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_fceb6d89-a883-4c61-b83f-b825a49abfcd" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockCapitalSharesReservedForFutureIssuance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3b882f42-843d-434f-ace0-fc17c99a22df" xlink:to="loc_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_fceb6d89-a883-4c61-b83f-b825a49abfcd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisePriceAsPercentOfWeightedAverageGrantDateFairValue_dae171dd-dcfe-4f2a-9f6e-973b6248c962" xlink:href="cpix-20231231.xsd#cpix_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisePriceAsPercentOfWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3b882f42-843d-434f-ace0-fc17c99a22df" xlink:to="loc_cpix_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisePriceAsPercentOfWeightedAverageGrantDateFairValue_dae171dd-dcfe-4f2a-9f6e-973b6248c962" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ShareBasedCompensationArrangementByShareBasedPaymentAwardShareholderPercent_cf3246f4-9601-4937-b58a-06a47724d50d" xlink:href="cpix-20231231.xsd#cpix_ShareBasedCompensationArrangementByShareBasedPaymentAwardShareholderPercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3b882f42-843d-434f-ace0-fc17c99a22df" xlink:to="loc_cpix_ShareBasedCompensationArrangementByShareBasedPaymentAwardShareholderPercent_cf3246f4-9601-4937-b58a-06a47724d50d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_7375359c-ac18-4eba-bc45-cb3ba6cc18bb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3b882f42-843d-434f-ace0-fc17c99a22df" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_7375359c-ac18-4eba-bc45-cb3ba6cc18bb" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_e14ec98c-7da6-4245-9ebd-c4f6c5b84189" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3b882f42-843d-434f-ace0-fc17c99a22df" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_e14ec98c-7da6-4245-9ebd-c4f6c5b84189" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_79ae1659-d100-41fc-afea-00f695cbb0c0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3b882f42-843d-434f-ace0-fc17c99a22df" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_79ae1659-d100-41fc-afea-00f695cbb0c0" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_80446f48-d664-48f1-8f72-d09b73351945" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3b882f42-843d-434f-ace0-fc17c99a22df" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_80446f48-d664-48f1-8f72-d09b73351945" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_670ed5a1-2ab9-41a5-aa30-0082d65e18ce" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3b882f42-843d-434f-ace0-fc17c99a22df" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_670ed5a1-2ab9-41a5-aa30-0082d65e18ce" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_73d719b1-82eb-4492-bf5a-e2d413c11609" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3b882f42-843d-434f-ace0-fc17c99a22df" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_73d719b1-82eb-4492-bf5a-e2d413c11609" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares_b088c026-8f6f-4cbd-989f-065014dd9a66" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3b882f42-843d-434f-ace0-fc17c99a22df" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares_b088c026-8f6f-4cbd-989f-065014dd9a66" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsWeightedAverageExpectedDividend_55e65324-ce0c-4d92-b0a3-c28eda7037a6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsWeightedAverageExpectedDividend"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3b882f42-843d-434f-ace0-fc17c99a22df" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsWeightedAverageExpectedDividend_55e65324-ce0c-4d92-b0a3-c28eda7037a6" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_b8a31c9e-cc46-412c-b5ea-4f759551cee7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3b882f42-843d-434f-ace0-fc17c99a22df" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_b8a31c9e-cc46-412c-b5ea-4f759551cee7" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue_9f932a1c-f217-44ff-bf91-87898fc6ca8f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3b882f42-843d-434f-ace0-fc17c99a22df" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue_9f932a1c-f217-44ff-bf91-87898fc6ca8f" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_3a2372d6-a014-4642-9d1a-8babe5a2e459" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3b882f42-843d-434f-ace0-fc17c99a22df" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_3a2372d6-a014-4642-9d1a-8babe5a2e459" xlink:type="arc" order="15"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cumberlandpharma.com/role/StockBasedCompensationPlansValuationAssumptionsDetails" xlink:type="simple" xlink:href="cpix-20231231.xsd#StockBasedCompensationPlansValuationAssumptionsDetails"/>
  <link:definitionLink xlink:role="http://www.cumberlandpharma.com/role/StockBasedCompensationPlansValuationAssumptionsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_49cc5629-c582-4269-8864-e43fb2e94b22" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_4a079d2d-616c-4814-9ce5-61b84571cfd2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_49cc5629-c582-4269-8864-e43fb2e94b22" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_4a079d2d-616c-4814-9ce5-61b84571cfd2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_9f2126d7-4f6a-4015-ad0a-67f997f11777" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_4a079d2d-616c-4814-9ce5-61b84571cfd2" xlink:to="loc_us-gaap_AwardTypeAxis_9f2126d7-4f6a-4015-ad0a-67f997f11777" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_9f2126d7-4f6a-4015-ad0a-67f997f11777_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_9f2126d7-4f6a-4015-ad0a-67f997f11777" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_9f2126d7-4f6a-4015-ad0a-67f997f11777_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_c4f054c6-cd4c-44bb-9b44-d94815ef88ba" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_9f2126d7-4f6a-4015-ad0a-67f997f11777" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_c4f054c6-cd4c-44bb-9b44-d94815ef88ba" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_950716c0-4837-4ca6-9c56-4cbc8789d008" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_c4f054c6-cd4c-44bb-9b44-d94815ef88ba" xlink:to="loc_us-gaap_EmployeeStockOptionMember_950716c0-4837-4ca6-9c56-4cbc8789d008" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_55ccf454-b07e-4c89-b974-581811df9307" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_49cc5629-c582-4269-8864-e43fb2e94b22" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_55ccf454-b07e-4c89-b974-581811df9307" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsWeightedAverageVolatilityRate_85831f30-568f-4e60-8823-50a8e1baf2e3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsWeightedAverageVolatilityRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_49cc5629-c582-4269-8864-e43fb2e94b22" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsWeightedAverageVolatilityRate_85831f30-568f-4e60-8823-50a8e1baf2e3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_e63eb401-c43d-4661-968c-fe620b4da01b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_49cc5629-c582-4269-8864-e43fb2e94b22" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_e63eb401-c43d-4661-968c-fe620b4da01b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsWeightedAverageExpectedDividend_dd8c0501-31ed-440c-b9e6-064b8194f0a5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsWeightedAverageExpectedDividend"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_49cc5629-c582-4269-8864-e43fb2e94b22" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsWeightedAverageExpectedDividend_dd8c0501-31ed-440c-b9e6-064b8194f0a5" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cumberlandpharma.com/role/StockBasedCompensationPlansRestrictedStockActivityDetails" xlink:type="simple" xlink:href="cpix-20231231.xsd#StockBasedCompensationPlansRestrictedStockActivityDetails"/>
  <link:definitionLink xlink:role="http://www.cumberlandpharma.com/role/StockBasedCompensationPlansRestrictedStockActivityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_7bc0c164-8c1c-422b-b5c4-5a1903ee5060" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_b2ff4e30-2018-42f2-9881-69039b29755e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_7bc0c164-8c1c-422b-b5c4-5a1903ee5060" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_b2ff4e30-2018-42f2-9881-69039b29755e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_6a794dbd-5ec4-480d-a18d-410f77012a87" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_b2ff4e30-2018-42f2-9881-69039b29755e" xlink:to="loc_us-gaap_AwardTypeAxis_6a794dbd-5ec4-480d-a18d-410f77012a87" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_6a794dbd-5ec4-480d-a18d-410f77012a87_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_6a794dbd-5ec4-480d-a18d-410f77012a87" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_6a794dbd-5ec4-480d-a18d-410f77012a87_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_99eb772f-d724-41b9-a781-91c01275c096" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_6a794dbd-5ec4-480d-a18d-410f77012a87" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_99eb772f-d724-41b9-a781-91c01275c096" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_75041e58-f747-4913-bf35-e414fedf9180" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_99eb772f-d724-41b9-a781-91c01275c096" xlink:to="loc_us-gaap_RestrictedStockMember_75041e58-f747-4913-bf35-e414fedf9180" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_76a6e497-92f0-45fc-9a24-1be1189f821f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_7bc0c164-8c1c-422b-b5c4-5a1903ee5060" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_76a6e497-92f0-45fc-9a24-1be1189f821f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_f1d8c976-7397-4dee-a272-f725e2e2d848" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_76a6e497-92f0-45fc-9a24-1be1189f821f" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_f1d8c976-7397-4dee-a272-f725e2e2d848" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_670418b2-81b1-4846-a76b-7dd212f0bd17" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_76a6e497-92f0-45fc-9a24-1be1189f821f" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_670418b2-81b1-4846-a76b-7dd212f0bd17" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_14b9f658-6e39-4dc6-961f-5c1f4a4bbdf7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_76a6e497-92f0-45fc-9a24-1be1189f821f" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_14b9f658-6e39-4dc6-961f-5c1f4a4bbdf7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_29c97060-e357-4519-967f-c7f8037c2c50" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_76a6e497-92f0-45fc-9a24-1be1189f821f" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_29c97060-e357-4519-967f-c7f8037c2c50" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_05fe627d-31d4-4d0b-9c56-cfeb488d85b1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_7c3ff650-a3ca-481e-82b0-2088a6a6e04a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_7bc0c164-8c1c-422b-b5c4-5a1903ee5060" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_7c3ff650-a3ca-481e-82b0-2088a6a6e04a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_1d2fa527-49be-4c7e-911e-60d248e12f00" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_7c3ff650-a3ca-481e-82b0-2088a6a6e04a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_1d2fa527-49be-4c7e-911e-60d248e12f00" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_ddae03da-f73c-4630-bba7-bf02f45eabd3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_7c3ff650-a3ca-481e-82b0-2088a6a6e04a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_ddae03da-f73c-4630-bba7-bf02f45eabd3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_fcf6d04e-f78b-4d22-a2cc-d930b48f0538" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_7c3ff650-a3ca-481e-82b0-2088a6a6e04a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_fcf6d04e-f78b-4d22-a2cc-d930b48f0538" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_e3af2d19-6889-4ab0-8622-b31ccf2bec03" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_7c3ff650-a3ca-481e-82b0-2088a6a6e04a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_e3af2d19-6889-4ab0-8622-b31ccf2bec03" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_befd23dc-d027-424a-b1c7-a59293504247" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cumberlandpharma.com/role/LeasesNarrativeDetails" xlink:type="simple" xlink:href="cpix-20231231.xsd#LeasesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.cumberlandpharma.com/role/LeasesNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeLeaseDescriptionLineItems_db08a750-0b63-4914-a501-59c2ce9f9448" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LesseeLeaseDescriptionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeLeaseDescriptionTable_a3b56b6b-6e75-4ba0-9ce6-81cc83c24378" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LesseeLeaseDescriptionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_db08a750-0b63-4914-a501-59c2ce9f9448" xlink:to="loc_us-gaap_LesseeLeaseDescriptionTable_a3b56b6b-6e75-4ba0-9ce6-81cc83c24378" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_b3a7b8f7-8276-4227-8a38-2dc2abd014ea" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LesseeLeaseDescriptionTable_a3b56b6b-6e75-4ba0-9ce6-81cc83c24378" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_b3a7b8f7-8276-4227-8a38-2dc2abd014ea" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_b3a7b8f7-8276-4227-8a38-2dc2abd014ea_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_b3a7b8f7-8276-4227-8a38-2dc2abd014ea" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_b3a7b8f7-8276-4227-8a38-2dc2abd014ea_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_4f0248e6-6de7-4c0d-a32e-9f98ad5c546c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_b3a7b8f7-8276-4227-8a38-2dc2abd014ea" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_4f0248e6-6de7-4c0d-a32e-9f98ad5c546c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OfficeBuildingMember_3cfff126-5bf5-4155-89f2-a6d5f02e085d" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_OfficeBuildingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_4f0248e6-6de7-4c0d-a32e-9f98ad5c546c" xlink:to="loc_srt_OfficeBuildingMember_3cfff126-5bf5-4155-89f2-a6d5f02e085d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseContractualTermAxis_0f45376c-8eae-439b-9fda-6791e54b33ee" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LeaseContractualTermAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LesseeLeaseDescriptionTable_a3b56b6b-6e75-4ba0-9ce6-81cc83c24378" xlink:to="loc_us-gaap_LeaseContractualTermAxis_0f45376c-8eae-439b-9fda-6791e54b33ee" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseContractualTermDomain_0f45376c-8eae-439b-9fda-6791e54b33ee_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LeaseContractualTermDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LeaseContractualTermAxis_0f45376c-8eae-439b-9fda-6791e54b33ee" xlink:to="loc_us-gaap_LeaseContractualTermDomain_0f45376c-8eae-439b-9fda-6791e54b33ee_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseContractualTermDomain_54f8045d-d125-41a4-92cb-435de203dd65" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LeaseContractualTermDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LeaseContractualTermAxis_0f45376c-8eae-439b-9fda-6791e54b33ee" xlink:to="loc_us-gaap_LeaseContractualTermDomain_54f8045d-d125-41a4-92cb-435de203dd65" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_BroadwestLeaseFiveYearRenewalOptionMember_404c10e9-0744-45ae-9b80-389050db96e4" xlink:href="cpix-20231231.xsd#cpix_BroadwestLeaseFiveYearRenewalOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LeaseContractualTermDomain_54f8045d-d125-41a4-92cb-435de203dd65" xlink:to="loc_cpix_BroadwestLeaseFiveYearRenewalOptionMember_404c10e9-0744-45ae-9b80-389050db96e4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_522dcdf0-6af0-41c7-87b6-bbef13e9da24" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_CounterpartyNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LesseeLeaseDescriptionTable_a3b56b6b-6e75-4ba0-9ce6-81cc83c24378" xlink:to="loc_srt_CounterpartyNameAxis_522dcdf0-6af0-41c7-87b6-bbef13e9da24" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_522dcdf0-6af0-41c7-87b6-bbef13e9da24_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_522dcdf0-6af0-41c7-87b6-bbef13e9da24" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_522dcdf0-6af0-41c7-87b6-bbef13e9da24_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_e3ef61fd-a65b-45fe-b1a3-43b9579f508d" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_522dcdf0-6af0-41c7-87b6-bbef13e9da24" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_e3ef61fd-a65b-45fe-b1a3-43b9579f508d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_A1600WestEndAvenuePartnersLLCMember_100d0739-1962-4540-a1a7-894858cc1014" xlink:href="cpix-20231231.xsd#cpix_A1600WestEndAvenuePartnersLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_e3ef61fd-a65b-45fe-b1a3-43b9579f508d" xlink:to="loc_cpix_A1600WestEndAvenuePartnersLLCMember_100d0739-1962-4540-a1a7-894858cc1014" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_NephronPharmaceuticalsCorporationNephronMember_b686f5a7-6708-4a77-9a7e-e83b1ceaeec1" xlink:href="cpix-20231231.xsd#cpix_NephronPharmaceuticalsCorporationNephronMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_e3ef61fd-a65b-45fe-b1a3-43b9579f508d" xlink:to="loc_cpix_NephronPharmaceuticalsCorporationNephronMember_b686f5a7-6708-4a77-9a7e-e83b1ceaeec1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_LesseeOperatingLeaseLeasedArea_a3e761f3-c64c-4c12-a90b-52eb101e3534" xlink:href="cpix-20231231.xsd#cpix_LesseeOperatingLeaseLeasedArea"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_db08a750-0b63-4914-a501-59c2ce9f9448" xlink:to="loc_cpix_LesseeOperatingLeaseLeasedArea_a3e761f3-c64c-4c12-a90b-52eb101e3534" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseTermOfContract_7fe8d1c6-eedb-4b81-a931-5843228fb761" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LesseeOperatingLeaseTermOfContract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_db08a750-0b63-4914-a501-59c2ce9f9448" xlink:to="loc_us-gaap_LesseeOperatingLeaseTermOfContract_7fe8d1c6-eedb-4b81-a931-5843228fb761" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_LesseeOperatingLeaseNumberOfRenewalTerms_1bdb3c85-68f4-41d4-a3a9-2f225b57cc2c" xlink:href="cpix-20231231.xsd#cpix_LesseeOperatingLeaseNumberOfRenewalTerms"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_db08a750-0b63-4914-a501-59c2ce9f9448" xlink:to="loc_cpix_LesseeOperatingLeaseNumberOfRenewalTerms_1bdb3c85-68f4-41d4-a3a9-2f225b57cc2c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseRenewalTerm_532f14ce-5296-4721-bd76-0fde9e67d2a0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LesseeOperatingLeaseRenewalTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_db08a750-0b63-4914-a501-59c2ce9f9448" xlink:to="loc_us-gaap_LesseeOperatingLeaseRenewalTerm_532f14ce-5296-4721-bd76-0fde9e67d2a0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_LesseeOperatingLeaseBaseRent_e649a8de-800a-464b-887f-fb5780d82f2f" xlink:href="cpix-20231231.xsd#cpix_LesseeOperatingLeaseBaseRent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_db08a750-0b63-4914-a501-59c2ce9f9448" xlink:to="loc_cpix_LesseeOperatingLeaseBaseRent_e649a8de-800a-464b-887f-fb5780d82f2f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_LesseeOperatingLeaseRentIncrease_aaf02735-9b23-45ae-9043-f4efe37ff31d" xlink:href="cpix-20231231.xsd#cpix_LesseeOperatingLeaseRentIncrease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_db08a750-0b63-4914-a501-59c2ce9f9448" xlink:to="loc_cpix_LesseeOperatingLeaseRentIncrease_aaf02735-9b23-45ae-9043-f4efe37ff31d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseRemainingLeaseTerm_c9945358-3872-448d-9b0a-f728683bac5f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LesseeOperatingLeaseRemainingLeaseTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_db08a750-0b63-4914-a501-59c2ce9f9448" xlink:to="loc_us-gaap_LesseeOperatingLeaseRemainingLeaseTerm_c9945358-3872-448d-9b0a-f728683bac5f" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AreaOfRealEstateProperty_ab96c40e-2359-47f3-8b06-2b81a9c8b78a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AreaOfRealEstateProperty"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_db08a750-0b63-4914-a501-59c2ce9f9448" xlink:to="loc_us-gaap_AreaOfRealEstateProperty_ab96c40e-2359-47f3-8b06-2b81a9c8b78a" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_e961dbab-ce12-4b51-8340-7e95abde12ad" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_db08a750-0b63-4914-a501-59c2ce9f9448" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_e961dbab-ce12-4b51-8340-7e95abde12ad" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_2c959adc-9909-4c4f-9578-759432b7a863" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_db08a750-0b63-4914-a501-59c2ce9f9448" xlink:to="loc_us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_2c959adc-9909-4c4f-9578-759432b7a863" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_f0d35eb9-2146-4715-9db8-d6b2a0d70854" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_db08a750-0b63-4914-a501-59c2ce9f9448" xlink:to="loc_us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_f0d35eb9-2146-4715-9db8-d6b2a0d70854" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LessorOperatingLeasePaymentsToBeReceived_7213511b-b5fe-48ce-9e04-0645ec0d5ed8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LessorOperatingLeasePaymentsToBeReceived"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_db08a750-0b63-4914-a501-59c2ce9f9448" xlink:to="loc_us-gaap_LessorOperatingLeasePaymentsToBeReceived_7213511b-b5fe-48ce-9e04-0645ec0d5ed8" xlink:type="arc" order="11"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cumberlandpharma.com/role/MarketConcentrationsScheduleofRevenuesConcentrationfromMajorCustomersandNarrativeDetails" xlink:type="simple" xlink:href="cpix-20231231.xsd#MarketConcentrationsScheduleofRevenuesConcentrationfromMajorCustomersandNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.cumberlandpharma.com/role/MarketConcentrationsScheduleofRevenuesConcentrationfromMajorCustomersandNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskLineItems_850651cb-8cdf-41f7-8175-5dba3a493ea1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTable_0e8f9144-7432-45e7-adc5-a490e8a83066" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_850651cb-8cdf-41f7-8175-5dba3a493ea1" xlink:to="loc_us-gaap_ConcentrationRiskTable_0e8f9144-7432-45e7-adc5-a490e8a83066" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_bebc1183-5681-4cae-b67d-ed605d00f691" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_0e8f9144-7432-45e7-adc5-a490e8a83066" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_bebc1183-5681-4cae-b67d-ed605d00f691" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_bebc1183-5681-4cae-b67d-ed605d00f691_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_bebc1183-5681-4cae-b67d-ed605d00f691" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_bebc1183-5681-4cae-b67d-ed605d00f691_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_61516898-9deb-4f73-90d1-e018ca777e8e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_bebc1183-5681-4cae-b67d-ed605d00f691" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_61516898-9deb-4f73-90d1-e018ca777e8e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerConcentrationRiskMember_397c6a0f-d2b3-4725-939e-635d793ee746" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CustomerConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_61516898-9deb-4f73-90d1-e018ca777e8e" xlink:to="loc_us-gaap_CustomerConcentrationRiskMember_397c6a0f-d2b3-4725-939e-635d793ee746" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_7d981cdc-1d17-4787-817e-dc3837d0cc59" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_0e8f9144-7432-45e7-adc5-a490e8a83066" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_7d981cdc-1d17-4787-817e-dc3837d0cc59" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_7d981cdc-1d17-4787-817e-dc3837d0cc59_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_7d981cdc-1d17-4787-817e-dc3837d0cc59" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_7d981cdc-1d17-4787-817e-dc3837d0cc59_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_e8920037-9a2f-4d5c-8bcc-f1bf0d523c77" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_7d981cdc-1d17-4787-817e-dc3837d0cc59" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_e8920037-9a2f-4d5c-8bcc-f1bf0d523c77" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_SalesRevenueGoodsGrossMember_e432cff3-3bcd-4f3f-9f13-0e49cdb8eff1" xlink:href="cpix-20231231.xsd#cpix_SalesRevenueGoodsGrossMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_e8920037-9a2f-4d5c-8bcc-f1bf0d523c77" xlink:to="loc_cpix_SalesRevenueGoodsGrossMember_e432cff3-3bcd-4f3f-9f13-0e49cdb8eff1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableMember_3ff18beb-f54d-4af6-90e5-085585dda25d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccountsReceivableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_e8920037-9a2f-4d5c-8bcc-f1bf0d523c77" xlink:to="loc_us-gaap_AccountsReceivableMember_3ff18beb-f54d-4af6-90e5-085585dda25d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MajorCustomersAxis_3444af84-ca75-4e63-984b-31c0573458b6" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MajorCustomersAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_0e8f9144-7432-45e7-adc5-a490e8a83066" xlink:to="loc_srt_MajorCustomersAxis_3444af84-ca75-4e63-984b-31c0573458b6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_3444af84-ca75-4e63-984b-31c0573458b6_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_MajorCustomersAxis_3444af84-ca75-4e63-984b-31c0573458b6" xlink:to="loc_srt_NameOfMajorCustomerDomain_3444af84-ca75-4e63-984b-31c0573458b6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_fc6e2722-6c0c-4945-ac21-c0f574d11ba0" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_MajorCustomersAxis_3444af84-ca75-4e63-984b-31c0573458b6" xlink:to="loc_srt_NameOfMajorCustomerDomain_fc6e2722-6c0c-4945-ac21-c0f574d11ba0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_CustomerOneMember_f36c7dd5-aa74-4378-b9f8-5f2ac929d45d" xlink:href="cpix-20231231.xsd#cpix_CustomerOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_fc6e2722-6c0c-4945-ac21-c0f574d11ba0" xlink:to="loc_cpix_CustomerOneMember_f36c7dd5-aa74-4378-b9f8-5f2ac929d45d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_CustomerTwoMember_782d68ba-8027-4629-ae64-ec74af5600de" xlink:href="cpix-20231231.xsd#cpix_CustomerTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_fc6e2722-6c0c-4945-ac21-c0f574d11ba0" xlink:to="loc_cpix_CustomerTwoMember_782d68ba-8027-4629-ae64-ec74af5600de" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_CustomerThreeMember_7014e488-2137-4171-8283-402473b378fa" xlink:href="cpix-20231231.xsd#cpix_CustomerThreeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_fc6e2722-6c0c-4945-ac21-c0f574d11ba0" xlink:to="loc_cpix_CustomerThreeMember_7014e488-2137-4171-8283-402473b378fa" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_Customer12And3Member_9bcc6a41-7851-4b18-b724-63ee05ed615f" xlink:href="cpix-20231231.xsd#cpix_Customer12And3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_fc6e2722-6c0c-4945-ac21-c0f574d11ba0" xlink:to="loc_cpix_Customer12And3Member_9bcc6a41-7851-4b18-b724-63ee05ed615f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_09a81088-15ab-4d6b-9e15-f3a529e00d5f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskPercentage1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_850651cb-8cdf-41f7-8175-5dba3a493ea1" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_09a81088-15ab-4d6b-9e15-f3a529e00d5f" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cumberlandpharma.com/role/ManufacturingandSupplyAgreementsManufacturingandSupplyAgreementsNarrativeDetails" xlink:type="simple" xlink:href="cpix-20231231.xsd#ManufacturingandSupplyAgreementsManufacturingandSupplyAgreementsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.cumberlandpharma.com/role/ManufacturingandSupplyAgreementsManufacturingandSupplyAgreementsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ManufacturingandSupplyAgreementLineItems_29d9a674-de9a-4c7a-99f8-3c5f76e84442" xlink:href="cpix-20231231.xsd#cpix_ManufacturingandSupplyAgreementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ManufacturingandSupplyAgreementTable_1419c6be-c66f-47c7-8840-9aa563df94d2" xlink:href="cpix-20231231.xsd#cpix_ManufacturingandSupplyAgreementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_cpix_ManufacturingandSupplyAgreementLineItems_29d9a674-de9a-4c7a-99f8-3c5f76e84442" xlink:to="loc_cpix_ManufacturingandSupplyAgreementTable_1419c6be-c66f-47c7-8840-9aa563df94d2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_3f9587e4-9bd6-4cde-9129-2f0d9e3ab049" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_cpix_ManufacturingandSupplyAgreementTable_1419c6be-c66f-47c7-8840-9aa563df94d2" xlink:to="loc_srt_RangeAxis_3f9587e4-9bd6-4cde-9129-2f0d9e3ab049" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_3f9587e4-9bd6-4cde-9129-2f0d9e3ab049_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_3f9587e4-9bd6-4cde-9129-2f0d9e3ab049" xlink:to="loc_srt_RangeMember_3f9587e4-9bd6-4cde-9129-2f0d9e3ab049_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_22078f62-d143-4547-8be5-fbb9ea52fbe9" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_3f9587e4-9bd6-4cde-9129-2f0d9e3ab049" xlink:to="loc_srt_RangeMember_22078f62-d143-4547-8be5-fbb9ea52fbe9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_2712859b-75d9-4cd7-bd87-5f69e76f4dd4" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_22078f62-d143-4547-8be5-fbb9ea52fbe9" xlink:to="loc_srt_MinimumMember_2712859b-75d9-4cd7-bd87-5f69e76f4dd4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_ef2c340d-3d29-4fca-b115-9a87010427ea" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_22078f62-d143-4547-8be5-fbb9ea52fbe9" xlink:to="loc_srt_MaximumMember_ef2c340d-3d29-4fca-b115-9a87010427ea" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ManufacturingAgreementsNumberOfPrimarySuppliersForEachProduct_d279d894-9997-450b-bd0e-e94dc586800d" xlink:href="cpix-20231231.xsd#cpix_ManufacturingAgreementsNumberOfPrimarySuppliersForEachProduct"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cpix_ManufacturingandSupplyAgreementLineItems_29d9a674-de9a-4c7a-99f8-3c5f76e84442" xlink:to="loc_cpix_ManufacturingAgreementsNumberOfPrimarySuppliersForEachProduct_d279d894-9997-450b-bd0e-e94dc586800d" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cumberlandpharma.com/role/CommitmentsandContingenciesDetails" xlink:type="simple" xlink:href="cpix-20231231.xsd#CommitmentsandContingenciesDetails"/>
  <link:definitionLink xlink:role="http://www.cumberlandpharma.com/role/CommitmentsandContingenciesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentsLineItems_e085b3f4-2fb1-415a-bf62-0c78ead30d0d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherCommitmentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentsTable_64d83f98-59f9-4079-9454-40b467f4f385" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherCommitmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_e085b3f4-2fb1-415a-bf62-0c78ead30d0d" xlink:to="loc_us-gaap_OtherCommitmentsTable_64d83f98-59f9-4079-9454-40b467f4f385" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_de0eafbb-f148-447a-9541-7755c8165f8a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_OtherCommitmentsTable_64d83f98-59f9-4079-9454-40b467f4f385" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_de0eafbb-f148-447a-9541-7755c8165f8a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_de0eafbb-f148-447a-9541-7755c8165f8a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_de0eafbb-f148-447a-9541-7755c8165f8a" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_de0eafbb-f148-447a-9541-7755c8165f8a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_faee813f-aaf9-4958-809e-28327df67a03" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_de0eafbb-f148-447a-9541-7755c8165f8a" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_faee813f-aaf9-4958-809e-28327df67a03" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_U.S.ProductAssetRightsSancusoMember_436e4cd6-edeb-4f77-9a51-4c5bb862392f" xlink:href="cpix-20231231.xsd#cpix_U.S.ProductAssetRightsSancusoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_faee813f-aaf9-4958-809e-28327df67a03" xlink:to="loc_cpix_U.S.ProductAssetRightsSancusoMember_436e4cd6-edeb-4f77-9a51-4c5bb862392f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_e875fceb-199f-4453-aeaa-6e13284761e5" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_OtherCommitmentsTable_64d83f98-59f9-4079-9454-40b467f4f385" xlink:to="loc_srt_RangeAxis_e875fceb-199f-4453-aeaa-6e13284761e5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_e875fceb-199f-4453-aeaa-6e13284761e5_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_e875fceb-199f-4453-aeaa-6e13284761e5" xlink:to="loc_srt_RangeMember_e875fceb-199f-4453-aeaa-6e13284761e5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_242062a5-ac7a-4f53-b23f-b00c6a9e3a7c" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_e875fceb-199f-4453-aeaa-6e13284761e5" xlink:to="loc_srt_RangeMember_242062a5-ac7a-4f53-b23f-b00c6a9e3a7c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_1c28be22-dd8c-47d9-9a36-aa41bea18c62" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_242062a5-ac7a-4f53-b23f-b00c6a9e3a7c" xlink:to="loc_srt_MaximumMember_1c28be22-dd8c-47d9-9a36-aa41bea18c62" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_688e90eb-ccfa-41a8-b0ac-a6010bb46904" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_242062a5-ac7a-4f53-b23f-b00c6a9e3a7c" xlink:to="loc_srt_MinimumMember_688e90eb-ccfa-41a8-b0ac-a6010bb46904" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_c43c2c13-be74-46bd-9d64-982e7a072e23" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_CounterpartyNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_OtherCommitmentsTable_64d83f98-59f9-4079-9454-40b467f4f385" xlink:to="loc_srt_CounterpartyNameAxis_c43c2c13-be74-46bd-9d64-982e7a072e23" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_c43c2c13-be74-46bd-9d64-982e7a072e23_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_c43c2c13-be74-46bd-9d64-982e7a072e23" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_c43c2c13-be74-46bd-9d64-982e7a072e23_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_31fd0ae4-cd78-440a-bfe1-c7186c921f34" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_c43c2c13-be74-46bd-9d64-982e7a072e23" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_31fd0ae4-cd78-440a-bfe1-c7186c921f34" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_MelintaTherapeuticsLLCAndTargantaTherapeuticsCorporationMember_c58bc552-16e9-43b5-af20-2db27bbd7f86" xlink:href="cpix-20231231.xsd#cpix_MelintaTherapeuticsLLCAndTargantaTherapeuticsCorporationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_31fd0ae4-cd78-440a-bfe1-c7186c921f34" xlink:to="loc_cpix_MelintaTherapeuticsLLCAndTargantaTherapeuticsCorporationMember_c58bc552-16e9-43b5-af20-2db27bbd7f86" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TypeOfArrangementAxis_d0c51263-ce9f-49bb-b33b-2a998b8506ac" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TypeOfArrangementAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_OtherCommitmentsTable_64d83f98-59f9-4079-9454-40b467f4f385" xlink:to="loc_us-gaap_TypeOfArrangementAxis_d0c51263-ce9f-49bb-b33b-2a998b8506ac" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_d0c51263-ce9f-49bb-b33b-2a998b8506ac_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TypeOfArrangementAxis_d0c51263-ce9f-49bb-b33b-2a998b8506ac" xlink:to="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_d0c51263-ce9f-49bb-b33b-2a998b8506ac_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_8f5325dc-93f3-4483-b602-83f2cbd36cd0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TypeOfArrangementAxis_d0c51263-ce9f-49bb-b33b-2a998b8506ac" xlink:to="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_8f5325dc-93f3-4483-b602-83f2cbd36cd0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollaborativeArrangementTransactionWithPartyToCollaborativeArrangementMember_97a52349-6750-413c-99d7-89655405efe2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CollaborativeArrangementTransactionWithPartyToCollaborativeArrangementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_8f5325dc-93f3-4483-b602-83f2cbd36cd0" xlink:to="loc_us-gaap_CollaborativeArrangementTransactionWithPartyToCollaborativeArrangementMember_97a52349-6750-413c-99d7-89655405efe2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_CollaborativeArrangementMilestonePaymentThresholdAxis_a14c6131-0c78-4043-adfa-87e0206ec233" xlink:href="cpix-20231231.xsd#cpix_CollaborativeArrangementMilestonePaymentThresholdAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_OtherCommitmentsTable_64d83f98-59f9-4079-9454-40b467f4f385" xlink:to="loc_cpix_CollaborativeArrangementMilestonePaymentThresholdAxis_a14c6131-0c78-4043-adfa-87e0206ec233" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_CollaborativeArrangementMilestonePaymentThresholdDomain_a14c6131-0c78-4043-adfa-87e0206ec233_default" xlink:href="cpix-20231231.xsd#cpix_CollaborativeArrangementMilestonePaymentThresholdDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_cpix_CollaborativeArrangementMilestonePaymentThresholdAxis_a14c6131-0c78-4043-adfa-87e0206ec233" xlink:to="loc_cpix_CollaborativeArrangementMilestonePaymentThresholdDomain_a14c6131-0c78-4043-adfa-87e0206ec233_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_CollaborativeArrangementMilestonePaymentThresholdDomain_535d0dfa-97c0-4686-8909-3a8e0d86cc7d" xlink:href="cpix-20231231.xsd#cpix_CollaborativeArrangementMilestonePaymentThresholdDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_cpix_CollaborativeArrangementMilestonePaymentThresholdAxis_a14c6131-0c78-4043-adfa-87e0206ec233" xlink:to="loc_cpix_CollaborativeArrangementMilestonePaymentThresholdDomain_535d0dfa-97c0-4686-8909-3a8e0d86cc7d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_Within30DaysOfFirstSNDAFilingMember_8fdbd967-9bf5-436c-ae43-5a500056b474" xlink:href="cpix-20231231.xsd#cpix_Within30DaysOfFirstSNDAFilingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cpix_CollaborativeArrangementMilestonePaymentThresholdDomain_535d0dfa-97c0-4686-8909-3a8e0d86cc7d" xlink:to="loc_cpix_Within30DaysOfFirstSNDAFilingMember_8fdbd967-9bf5-436c-ae43-5a500056b474" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_FollowingApprovalOfFirstSNDAMember_1163b580-ceda-4d68-b34e-e3d1f7753ab4" xlink:href="cpix-20231231.xsd#cpix_FollowingApprovalOfFirstSNDAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cpix_CollaborativeArrangementMilestonePaymentThresholdDomain_535d0dfa-97c0-4686-8909-3a8e0d86cc7d" xlink:to="loc_cpix_FollowingApprovalOfFirstSNDAMember_1163b580-ceda-4d68-b34e-e3d1f7753ab4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_PaymentsToAcquireBusinessTieredRoyaltyPaymentsThreshold_828bd3c1-8654-4a5a-9cce-7f61c47e5a23" xlink:href="cpix-20231231.xsd#cpix_PaymentsToAcquireBusinessTieredRoyaltyPaymentsThreshold"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_e085b3f4-2fb1-415a-bf62-0c78ead30d0d" xlink:to="loc_cpix_PaymentsToAcquireBusinessTieredRoyaltyPaymentsThreshold_828bd3c1-8654-4a5a-9cce-7f61c47e5a23" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_PaymentsToAcquireBusinessTieredRoyaltyPaymentsPercentage_95c59d9a-5cda-42e8-af32-34af80a5c49f" xlink:href="cpix-20231231.xsd#cpix_PaymentsToAcquireBusinessTieredRoyaltyPaymentsPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_e085b3f4-2fb1-415a-bf62-0c78ead30d0d" xlink:to="loc_cpix_PaymentsToAcquireBusinessTieredRoyaltyPaymentsPercentage_95c59d9a-5cda-42e8-af32-34af80a5c49f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_PaymentsToAcquireBusinessTieredRoyaltyPaymentsTerm_70b37043-e284-446a-a6d0-d05162d507b4" xlink:href="cpix-20231231.xsd#cpix_PaymentsToAcquireBusinessTieredRoyaltyPaymentsTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_e085b3f4-2fb1-415a-bf62-0c78ead30d0d" xlink:to="loc_cpix_PaymentsToAcquireBusinessTieredRoyaltyPaymentsTerm_70b37043-e284-446a-a6d0-d05162d507b4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_CollaborativeArrangementRightsAndObligationsSalesMilestonePaymentsReceivable_d9af79fe-4544-4299-a829-436dce116abe" xlink:href="cpix-20231231.xsd#cpix_CollaborativeArrangementRightsAndObligationsSalesMilestonePaymentsReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_e085b3f4-2fb1-415a-bf62-0c78ead30d0d" xlink:to="loc_cpix_CollaborativeArrangementRightsAndObligationsSalesMilestonePaymentsReceivable_d9af79fe-4544-4299-a829-436dce116abe" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromLegalSettlements_fccaadc2-687a-4361-95f5-5d41fc979726" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromLegalSettlements"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_e085b3f4-2fb1-415a-bf62-0c78ead30d0d" xlink:to="loc_us-gaap_ProceedsFromLegalSettlements_fccaadc2-687a-4361-95f5-5d41fc979726" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cumberlandpharma.com/role/ValuationandQualifyingAccountsDetails" xlink:type="simple" xlink:href="cpix-20231231.xsd#ValuationandQualifyingAccountsDetails"/>
  <link:definitionLink xlink:role="http://www.cumberlandpharma.com/role/ValuationandQualifyingAccountsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_srt_ValuationAndQualifyingAccountsDisclosureLineItems_9d243d55-04ff-4f15-852f-9683d8639595" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ValuationAndQualifyingAccountsDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ValuationAndQualifyingAccountsDisclosureTable_cf5949e3-d938-491a-ae40-d363d8573c97" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ValuationAndQualifyingAccountsDisclosureTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_srt_ValuationAndQualifyingAccountsDisclosureLineItems_9d243d55-04ff-4f15-852f-9683d8639595" xlink:to="loc_srt_ValuationAndQualifyingAccountsDisclosureTable_cf5949e3-d938-491a-ae40-d363d8573c97" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_79747ed1-c213-4e93-a0e5-0898249bba8d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ValuationAllowancesAndReservesTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_srt_ValuationAndQualifyingAccountsDisclosureTable_cf5949e3-d938-491a-ae40-d363d8573c97" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_79747ed1-c213-4e93-a0e5-0898249bba8d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesDomain_79747ed1-c213-4e93-a0e5-0898249bba8d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ValuationAllowancesAndReservesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_79747ed1-c213-4e93-a0e5-0898249bba8d" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesDomain_79747ed1-c213-4e93-a0e5-0898249bba8d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesDomain_884c3ab0-3aab-4195-b384-8a03ad1b5006" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ValuationAllowancesAndReservesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_79747ed1-c213-4e93-a0e5-0898249bba8d" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesDomain_884c3ab0-3aab-4195-b384-8a03ad1b5006" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllowanceForCreditLossMember_4330f16e-e423-4527-83ee-02cece21b98d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AllowanceForCreditLossMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesDomain_884c3ab0-3aab-4195-b384-8a03ad1b5006" xlink:to="loc_us-gaap_AllowanceForCreditLossMember_4330f16e-e423-4527-83ee-02cece21b98d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowanceOfDeferredTaxAssetsMember_9ccc99af-a992-485b-b2b8-7ebbafad57f6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ValuationAllowanceOfDeferredTaxAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesDomain_884c3ab0-3aab-4195-b384-8a03ad1b5006" xlink:to="loc_us-gaap_ValuationAllowanceOfDeferredTaxAssetsMember_9ccc99af-a992-485b-b2b8-7ebbafad57f6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_07e33499-6918-4cdd-a88d-27b2d7c63d08" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MovementInValuationAllowancesAndReservesRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ValuationAndQualifyingAccountsDisclosureLineItems_9d243d55-04ff-4f15-852f-9683d8639595" xlink:to="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_07e33499-6918-4cdd-a88d-27b2d7c63d08" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesBalance_4642aac6-be60-4dd5-a578-a695cad9bf81" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ValuationAllowancesAndReservesBalance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_07e33499-6918-4cdd-a88d-27b2d7c63d08" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesBalance_4642aac6-be60-4dd5-a578-a695cad9bf81" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense_c93d0aab-1d30-41f3-a6de-0df7e1a61c4b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_07e33499-6918-4cdd-a88d-27b2d7c63d08" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense_c93d0aab-1d30-41f3-a6de-0df7e1a61c4b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts_b65dd8da-00a5-454d-9dc2-790d41d70b6f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_07e33499-6918-4cdd-a88d-27b2d7c63d08" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts_b65dd8da-00a5-454d-9dc2-790d41d70b6f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesDeductions_b4b49b0d-4bcf-43ac-b0b5-819e4f39cd2b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ValuationAllowancesAndReservesDeductions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_07e33499-6918-4cdd-a88d-27b2d7c63d08" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesDeductions_b4b49b0d-4bcf-43ac-b0b5-819e4f39cd2b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesBalance_000ef178-7f9d-4862-8234-7dfb3540535f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ValuationAllowancesAndReservesBalance"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://xbrl.sec.gov/ecd/AwardTypeOnly" xlink:type="simple" xlink:href="https://xbrl.sec.gov/ecd/2023/ecd-2023.xsd#AwardTypeOnly"/>
  <link:definitionLink xlink:role="http://xbrl.sec.gov/ecd/AwardTypeOnly" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="loc_us-gaap_RestrictedStockMember" xlink:type="arc" order="4"/>
  </link:definitionLink>
</link:linkbase>
