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

<!--XBRL Document Created with Wdesk from Workiva-->
<!--Copyright 2021 Workiva-->
<!--r:719f38f6-81ec-4e77-a876-c86386f0dd09,g:3c5f884f-ec0b-48db-97a2-96993ede30b3-->
<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/CondensedConsolidatedStatementofEquity" xlink:type="simple" xlink:href="cpix-20210930.xsd#CondensedConsolidatedStatementofEquity"/>
  <link:definitionLink xlink:role="http://www.cumberlandpharma.com/role/CondensedConsolidatedStatementofEquity" xlink:type="extended" id="i6a54cc750a854548a9c68e4a1f8736a9_CondensedConsolidatedStatementofEquity">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_f7c2e9a6-a36a-4563-a86c-80c1462f6f63" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_1beabf0f-f1e7-4ae4-8f05-4e00568019c7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_f7c2e9a6-a36a-4563-a86c-80c1462f6f63" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_1beabf0f-f1e7-4ae4-8f05-4e00568019c7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_2eea1cc5-8e2f-4469-8b3e-02b3f9ab92ca" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_1beabf0f-f1e7-4ae4-8f05-4e00568019c7" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_2eea1cc5-8e2f-4469-8b3e-02b3f9ab92ca" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_3fc53be7-de5a-4bc2-a466-e48647c29ebf" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_1beabf0f-f1e7-4ae4-8f05-4e00568019c7" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_3fc53be7-de5a-4bc2-a466-e48647c29ebf" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_9ac63f16-655b-43be-a4e3-fef0c786814f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_1beabf0f-f1e7-4ae4-8f05-4e00568019c7" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_9ac63f16-655b-43be-a4e3-fef0c786814f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_a616b102-9203-43f3-ad9a-8794e1dea0b8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_1beabf0f-f1e7-4ae4-8f05-4e00568019c7" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_a616b102-9203-43f3-ad9a-8794e1dea0b8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodValue_02261b60-5b81-4cea-97de-5518756f4827" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockRepurchasedDuringPeriodValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_1beabf0f-f1e7-4ae4-8f05-4e00568019c7" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodValue_02261b60-5b81-4cea-97de-5518756f4827" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodShares_50403b23-09a6-463c-a646-4a8a4af80ca6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockRepurchasedDuringPeriodShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_1beabf0f-f1e7-4ae4-8f05-4e00568019c7" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodShares_50403b23-09a6-463c-a646-4a8a4af80ca6" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_0cf9e5e3-0e1f-4fb2-86c3-a5c4f6c85d03" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_1beabf0f-f1e7-4ae4-8f05-4e00568019c7" xlink:to="loc_us-gaap_ProfitLoss_0cf9e5e3-0e1f-4fb2-86c3-a5c4f6c85d03" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_7a25ff65-d2f8-40b3-8800-bc96f35ea165" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_115063ec-ba4d-423a-891f-54a20007d878" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_48306e8f-4abb-4cef-95d8-dd77dd686950" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_f7c2e9a6-a36a-4563-a86c-80c1462f6f63" xlink:to="loc_us-gaap_StatementTable_48306e8f-4abb-4cef-95d8-dd77dd686950" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_b3dd39aa-22ee-4410-b263-056381d6530c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_48306e8f-4abb-4cef-95d8-dd77dd686950" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_b3dd39aa-22ee-4410-b263-056381d6530c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_b3dd39aa-22ee-4410-b263-056381d6530c_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_b3dd39aa-22ee-4410-b263-056381d6530c" xlink:to="loc_us-gaap_EquityComponentDomain_b3dd39aa-22ee-4410-b263-056381d6530c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_9b72bcee-bd37-4a30-b13d-9f72fa193fca" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_b3dd39aa-22ee-4410-b263-056381d6530c" xlink:to="loc_us-gaap_EquityComponentDomain_9b72bcee-bd37-4a30-b13d-9f72fa193fca" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_94341e32-a24a-4a97-b865-262cfefbee68" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_9b72bcee-bd37-4a30-b13d-9f72fa193fca" xlink:to="loc_us-gaap_CommonStockMember_94341e32-a24a-4a97-b865-262cfefbee68" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_a8892951-fb38-4532-a2ab-f15f8516eb75" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_9b72bcee-bd37-4a30-b13d-9f72fa193fca" xlink:to="loc_us-gaap_RetainedEarningsMember_a8892951-fb38-4532-a2ab-f15f8516eb75" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestMember_97242877-524d-4dce-ae96-c586ca3ab29e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NoncontrollingInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_9b72bcee-bd37-4a30-b13d-9f72fa193fca" xlink:to="loc_us-gaap_NoncontrollingInterestMember_97242877-524d-4dce-ae96-c586ca3ab29e" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cumberlandpharma.com/role/RevenuesDetails" xlink:type="simple" xlink:href="cpix-20210930.xsd#RevenuesDetails"/>
  <link:definitionLink xlink:role="http://www.cumberlandpharma.com/role/RevenuesDetails" xlink:type="extended" id="ic1019e4191f0414d8243fc457f1074ba_RevenuesDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EntityWideInformationRevenueFromExternalCustomerLineItems_734d2712-5858-4a27-a866-f899e4111979" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EntityWideInformationRevenueFromExternalCustomerLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesAbstract_cabf3418-a5ae-4f2d-bfa2-00edf4297517" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenuesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EntityWideInformationRevenueFromExternalCustomerLineItems_734d2712-5858-4a27-a866-f899e4111979" xlink:to="loc_us-gaap_RevenuesAbstract_cabf3418-a5ae-4f2d-bfa2-00edf4297517" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ProductsAbstract_b7f59a5d-573f-4c4b-907f-2d14d80f41f7" xlink:href="cpix-20210930.xsd#cpix_ProductsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesAbstract_cabf3418-a5ae-4f2d-bfa2-00edf4297517" xlink:to="loc_cpix_ProductsAbstract_b7f59a5d-573f-4c4b-907f-2d14d80f41f7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_a9b697b5-652d-4f60-a2d7-25b146d15337" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cpix_ProductsAbstract_b7f59a5d-573f-4c4b-907f-2d14d80f41f7" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_a9b697b5-652d-4f60-a2d7-25b146d15337" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTable_e425ca26-2d14-444f-b7fd-a4ca025fb0e4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EntityWideInformationRevenueFromExternalCustomerLineItems_734d2712-5858-4a27-a866-f899e4111979" xlink:to="loc_us-gaap_ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTable_e425ca26-2d14-444f-b7fd-a4ca025fb0e4" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_ea85ad4b-cddd-4c70-a69b-d422c9f973f7" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTable_e425ca26-2d14-444f-b7fd-a4ca025fb0e4" xlink:to="loc_srt_ProductOrServiceAxis_ea85ad4b-cddd-4c70-a69b-d422c9f973f7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_ea85ad4b-cddd-4c70-a69b-d422c9f973f7_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_ea85ad4b-cddd-4c70-a69b-d422c9f973f7" xlink:to="loc_srt_ProductsAndServicesDomain_ea85ad4b-cddd-4c70-a69b-d422c9f973f7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_c5dd95e8-54d6-4959-883d-f9a456f42934" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_ea85ad4b-cddd-4c70-a69b-d422c9f973f7" xlink:to="loc_srt_ProductsAndServicesDomain_c5dd95e8-54d6-4959-883d-f9a456f42934" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_AcetadoteMember_da36bad0-a580-4de6-bc72-a3d26324cd1b" xlink:href="cpix-20210930.xsd#cpix_AcetadoteMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_c5dd95e8-54d6-4959-883d-f9a456f42934" xlink:to="loc_cpix_AcetadoteMember_da36bad0-a580-4de6-bc72-a3d26324cd1b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_OmeclamoxPakMember_c27b32ff-3a9d-4ae8-9470-f838a0bc70a1" xlink:href="cpix-20210930.xsd#cpix_OmeclamoxPakMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_c5dd95e8-54d6-4959-883d-f9a456f42934" xlink:to="loc_cpix_OmeclamoxPakMember_c27b32ff-3a9d-4ae8-9470-f838a0bc70a1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_KristaloseMember_8d10004d-9f1a-4b2f-8c06-0d85a0805803" xlink:href="cpix-20210930.xsd#cpix_KristaloseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_c5dd95e8-54d6-4959-883d-f9a456f42934" xlink:to="loc_cpix_KristaloseMember_8d10004d-9f1a-4b2f-8c06-0d85a0805803" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_VaprisolMember_a433841e-56a8-4f31-a0f5-1c9ac4523065" xlink:href="cpix-20210930.xsd#cpix_VaprisolMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_c5dd95e8-54d6-4959-883d-f9a456f42934" xlink:to="loc_cpix_VaprisolMember_a433841e-56a8-4f31-a0f5-1c9ac4523065" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_CaldolorMember_b0abc34d-da75-403b-a6be-5392060ff765" xlink:href="cpix-20210930.xsd#cpix_CaldolorMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_c5dd95e8-54d6-4959-883d-f9a456f42934" xlink:to="loc_cpix_CaldolorMember_b0abc34d-da75-403b-a6be-5392060ff765" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_VIBATIVMember_453c4bfa-ffbc-4f55-a4a0-59ed179c71c4" xlink:href="cpix-20210930.xsd#cpix_VIBATIVMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_c5dd95e8-54d6-4959-883d-f9a456f42934" xlink:to="loc_cpix_VIBATIVMember_453c4bfa-ffbc-4f55-a4a0-59ed179c71c4" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_RediTrexMember_f65bdec8-433e-480f-96ba-4ca60e7d5249" xlink:href="cpix-20210930.xsd#cpix_RediTrexMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_c5dd95e8-54d6-4959-883d-f9a456f42934" xlink:to="loc_cpix_RediTrexMember_f65bdec8-433e-480f-96ba-4ca60e7d5249" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_OtherProductsMember_6c40e545-0aff-4bd1-bad2-a8cc67cad621" xlink:href="cpix-20210930.xsd#cpix_OtherProductsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_c5dd95e8-54d6-4959-883d-f9a456f42934" xlink:to="loc_cpix_OtherProductsMember_6c40e545-0aff-4bd1-bad2-a8cc67cad621" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrantMember_6fa6505e-2e11-48e7-9bb7-b40fa8f1d88d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GrantMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_c5dd95e8-54d6-4959-883d-f9a456f42934" xlink:to="loc_us-gaap_GrantMember_6fa6505e-2e11-48e7-9bb7-b40fa8f1d88d" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cumberlandpharma.com/role/InventoriesNarrativeDetails" xlink:type="simple" xlink:href="cpix-20210930.xsd#InventoriesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.cumberlandpharma.com/role/InventoriesNarrativeDetails" xlink:type="extended" id="id49804daf3d24475bdbf1f8d946201e9_InventoriesNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryLineItems_2677b945-1379-4f43-b473-fcbb33c8672a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InventoryLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryValuationReserves_6ceb65bc-3f32-448c-bd36-e8d24a182c40" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InventoryValuationReserves"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InventoryLineItems_2677b945-1379-4f43-b473-fcbb33c8672a" xlink:to="loc_us-gaap_InventoryValuationReserves_6ceb65bc-3f32-448c-bd36-e8d24a182c40" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryNoncurrent_bdc2f651-0530-4433-920f-195aa7565b4e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InventoryNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InventoryLineItems_2677b945-1379-4f43-b473-fcbb33c8672a" xlink:to="loc_us-gaap_InventoryNoncurrent_bdc2f651-0530-4433-920f-195aa7565b4e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryFinishedGoods_bbf4892d-163a-4e3d-a2e7-2b4988289caa" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InventoryFinishedGoods"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InventoryLineItems_2677b945-1379-4f43-b473-fcbb33c8672a" xlink:to="loc_us-gaap_InventoryFinishedGoods_bbf4892d-163a-4e3d-a2e7-2b4988289caa" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryFinishedGoodsNetOfReserves_0db0db49-31ad-434a-8794-a060fe279721" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InventoryFinishedGoodsNetOfReserves"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InventoryLineItems_2677b945-1379-4f43-b473-fcbb33c8672a" xlink:to="loc_us-gaap_InventoryFinishedGoodsNetOfReserves_0db0db49-31ad-434a-8794-a060fe279721" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryCurrentTable_a0b336b1-ce47-4233-8c49-b2149cbf97b0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InventoryCurrentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_InventoryLineItems_2677b945-1379-4f43-b473-fcbb33c8672a" xlink:to="loc_us-gaap_InventoryCurrentTable_a0b336b1-ce47-4233-8c49-b2149cbf97b0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_14e80154-b32c-4526-a987-e7dae298d58a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_InventoryCurrentTable_a0b336b1-ce47-4233-8c49-b2149cbf97b0" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_14e80154-b32c-4526-a987-e7dae298d58a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_14e80154-b32c-4526-a987-e7dae298d58a_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_14e80154-b32c-4526-a987-e7dae298d58a" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_14e80154-b32c-4526-a987-e7dae298d58a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_080a77a9-fbcc-4871-ad9a-9b29db13a53f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_14e80154-b32c-4526-a987-e7dae298d58a" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_080a77a9-fbcc-4871-ad9a-9b29db13a53f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_IfetrobanClinicalMember_762200de-c65f-4d46-92dd-adda1c9d1347" xlink:href="cpix-20210930.xsd#cpix_IfetrobanClinicalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_080a77a9-fbcc-4871-ad9a-9b29db13a53f" xlink:to="loc_cpix_IfetrobanClinicalMember_762200de-c65f-4d46-92dd-adda1c9d1347" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_VIBATIVMember_d981f915-b2c0-4e48-8935-37217a2cc260" xlink:href="cpix-20210930.xsd#cpix_VIBATIVMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_080a77a9-fbcc-4871-ad9a-9b29db13a53f" xlink:to="loc_cpix_VIBATIVMember_d981f915-b2c0-4e48-8935-37217a2cc260" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesInventoryAxis_12a92061-068d-47a8-b4fa-e0f6209b630d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PublicUtilitiesInventoryAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_InventoryCurrentTable_a0b336b1-ce47-4233-8c49-b2149cbf97b0" xlink:to="loc_us-gaap_PublicUtilitiesInventoryAxis_12a92061-068d-47a8-b4fa-e0f6209b630d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_12a92061-068d-47a8-b4fa-e0f6209b630d_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PublicUtilitiesInventoryTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PublicUtilitiesInventoryAxis_12a92061-068d-47a8-b4fa-e0f6209b630d" xlink:to="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_12a92061-068d-47a8-b4fa-e0f6209b630d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_62ea1003-d7f0-4193-9fa7-15a5f1339c82" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PublicUtilitiesInventoryTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PublicUtilitiesInventoryAxis_12a92061-068d-47a8-b4fa-e0f6209b630d" xlink:to="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_62ea1003-d7f0-4193-9fa7-15a5f1339c82" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_IfetrobanClinicalMember_f4ca23e0-d093-45be-91fe-e13d47a86b56" xlink:href="cpix-20210930.xsd#cpix_IfetrobanClinicalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_62ea1003-d7f0-4193-9fa7-15a5f1339c82" xlink:to="loc_cpix_IfetrobanClinicalMember_f4ca23e0-d093-45be-91fe-e13d47a86b56" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cumberlandpharma.com/role/LeasesNarrativeDetails" xlink:type="simple" xlink:href="cpix-20210930.xsd#LeasesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.cumberlandpharma.com/role/LeasesNarrativeDetails" xlink:type="extended" id="i8937210d1feb445ab11fbac33ab5b41d_LeasesNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeLeaseDescriptionLineItems_1605487e-e0f6-4306-b5ca-7782f823edcd" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeLeaseDescriptionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AreaOfRealEstateProperty_2d366c01-a172-4ddd-becb-3cd44be795e9" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AreaOfRealEstateProperty"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_1605487e-e0f6-4306-b5ca-7782f823edcd" xlink:to="loc_us-gaap_AreaOfRealEstateProperty_2d366c01-a172-4ddd-becb-3cd44be795e9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_bc317288-facc-46d7-8afe-50d71f1d6181" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_1605487e-e0f6-4306-b5ca-7782f823edcd" xlink:to="loc_us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_bc317288-facc-46d7-8afe-50d71f1d6181" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_47cadbee-2542-4917-9e1b-fac050365ff2" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_1605487e-e0f6-4306-b5ca-7782f823edcd" xlink:to="loc_us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_47cadbee-2542-4917-9e1b-fac050365ff2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LessorOperatingLeasePaymentsToBeReceived_677942a7-adcf-467b-be5c-ee7208957a17" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LessorOperatingLeasePaymentsToBeReceived"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_1605487e-e0f6-4306-b5ca-7782f823edcd" xlink:to="loc_us-gaap_LessorOperatingLeasePaymentsToBeReceived_677942a7-adcf-467b-be5c-ee7208957a17" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeLeaseDescriptionTable_3bd25538-a25a-4f95-ac3a-183935816b0d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeLeaseDescriptionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_1605487e-e0f6-4306-b5ca-7782f823edcd" xlink:to="loc_us-gaap_LesseeLeaseDescriptionTable_3bd25538-a25a-4f95-ac3a-183935816b0d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_744461e7-343f-4ce0-88e8-462cd55aea36" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LesseeLeaseDescriptionTable_3bd25538-a25a-4f95-ac3a-183935816b0d" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_744461e7-343f-4ce0-88e8-462cd55aea36" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_744461e7-343f-4ce0-88e8-462cd55aea36_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_744461e7-343f-4ce0-88e8-462cd55aea36" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_744461e7-343f-4ce0-88e8-462cd55aea36_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_8fb4ce31-a05c-40ef-92f7-f9e38d139381" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_744461e7-343f-4ce0-88e8-462cd55aea36" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_8fb4ce31-a05c-40ef-92f7-f9e38d139381" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BuildingMember_3fc8fde7-facd-4ec6-81d3-b7eed954ffac" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BuildingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_8fb4ce31-a05c-40ef-92f7-f9e38d139381" xlink:to="loc_us-gaap_BuildingMember_3fc8fde7-facd-4ec6-81d3-b7eed954ffac" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OfficeBuildingMember_d1b199e9-1204-4946-b7ca-596cc966f447" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_OfficeBuildingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_8fb4ce31-a05c-40ef-92f7-f9e38d139381" xlink:to="loc_srt_OfficeBuildingMember_d1b199e9-1204-4946-b7ca-596cc966f447" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cumberlandpharma.com/role/ShareholdersEquityandDebtShareholdersEquityDetails" xlink:type="simple" xlink:href="cpix-20210930.xsd#ShareholdersEquityandDebtShareholdersEquityDetails"/>
  <link:definitionLink xlink:role="http://www.cumberlandpharma.com/role/ShareholdersEquityandDebtShareholdersEquityDetails" xlink:type="extended" id="ie40cd2367fa14173b739e55366816b88_ShareholdersEquityandDebtShareholdersEquityDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0e2d7da7-4ea8-4146-be48-882ec29b6419" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ShareholdersEquityTextualAbstract_dce969f5-2d4b-419b-a3a1-22d26930068b" xlink:href="cpix-20210930.xsd#cpix_ShareholdersEquityTextualAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0e2d7da7-4ea8-4146-be48-882ec29b6419" xlink:to="loc_cpix_ShareholdersEquityTextualAbstract_dce969f5-2d4b-419b-a3a1-22d26930068b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchaseProgramAuthorizedAmount1_a899ac8b-6845-402d-a04e-be85c00dec06" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockRepurchaseProgramAuthorizedAmount1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cpix_ShareholdersEquityTextualAbstract_dce969f5-2d4b-419b-a3a1-22d26930068b" xlink:to="loc_us-gaap_StockRepurchaseProgramAuthorizedAmount1_a899ac8b-6845-402d-a04e-be85c00dec06" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodShares_5f8700fb-8183-4a3e-8204-72cad17effcb" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockRepurchasedDuringPeriodShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cpix_ShareholdersEquityTextualAbstract_dce969f5-2d4b-419b-a3a1-22d26930068b" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodShares_5f8700fb-8183-4a3e-8204-72cad17effcb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodValue_28de0e93-1d84-4a8d-bcbd-f9fc6ee2438a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockRepurchasedDuringPeriodValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cpix_ShareholdersEquityTextualAbstract_dce969f5-2d4b-419b-a3a1-22d26930068b" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodValue_28de0e93-1d84-4a8d-bcbd-f9fc6ee2438a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_157796a8-03d2-4355-9e26-67e8f44f04c4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cpix_ShareholdersEquityTextualAbstract_dce969f5-2d4b-419b-a3a1-22d26930068b" xlink:to="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_157796a8-03d2-4355-9e26-67e8f44f04c4" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_StockIssuedDuringPeriodShelfRegistrationProceedsFromSaleofCorporateSecurities_a02c5b3f-77e9-406d-ad14-19bcc22189b9" xlink:href="cpix-20210930.xsd#cpix_StockIssuedDuringPeriodShelfRegistrationProceedsFromSaleofCorporateSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cpix_ShareholdersEquityTextualAbstract_dce969f5-2d4b-419b-a3a1-22d26930068b" xlink:to="loc_cpix_StockIssuedDuringPeriodShelfRegistrationProceedsFromSaleofCorporateSecurities_a02c5b3f-77e9-406d-ad14-19bcc22189b9" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_0125cc7e-b8e5-4a55-b545-65ed3bb675d6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cpix_ShareholdersEquityTextualAbstract_dce969f5-2d4b-419b-a3a1-22d26930068b" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_0125cc7e-b8e5-4a55-b545-65ed3bb675d6" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_36ce7cc7-bbb1-4df2-891c-29d7f7bccfdd" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cpix_ShareholdersEquityTextualAbstract_dce969f5-2d4b-419b-a3a1-22d26930068b" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_36ce7cc7-bbb1-4df2-891c-29d7f7bccfdd" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_41dc7f81-ea80-40fe-9466-2dfb24a12be8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0e2d7da7-4ea8-4146-be48-882ec29b6419" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_41dc7f81-ea80-40fe-9466-2dfb24a12be8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_d32074c5-5f6d-47b6-9172-975d23300470" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_41dc7f81-ea80-40fe-9466-2dfb24a12be8" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_d32074c5-5f6d-47b6-9172-975d23300470" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_d32074c5-5f6d-47b6-9172-975d23300470_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_d32074c5-5f6d-47b6-9172-975d23300470" xlink:to="loc_us-gaap_EquityComponentDomain_d32074c5-5f6d-47b6-9172-975d23300470_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_6d214517-3496-46ea-b310-30f77abd0996" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_d32074c5-5f6d-47b6-9172-975d23300470" xlink:to="loc_us-gaap_EquityComponentDomain_6d214517-3496-46ea-b310-30f77abd0996" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_3dccb701-ecec-4cf5-a759-0ec3baa98c2a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_6d214517-3496-46ea-b310-30f77abd0996" xlink:to="loc_us-gaap_CommonStockMember_3dccb701-ecec-4cf5-a759-0ec3baa98c2a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_TitleOfIndividualAxis_41ae3094-cee4-4790-8a7f-6effec343507" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_TitleOfIndividualAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_41dc7f81-ea80-40fe-9466-2dfb24a12be8" xlink:to="loc_srt_TitleOfIndividualAxis_41ae3094-cee4-4790-8a7f-6effec343507" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_41ae3094-cee4-4790-8a7f-6effec343507_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_TitleOfIndividualAxis_41ae3094-cee4-4790-8a7f-6effec343507" xlink:to="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_41ae3094-cee4-4790-8a7f-6effec343507_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_710fbba4-f8bf-413c-b4d8-a4a63861569e" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_TitleOfIndividualAxis_41ae3094-cee4-4790-8a7f-6effec343507" xlink:to="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_710fbba4-f8bf-413c-b4d8-a4a63861569e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_DirectorMember_c81f76fa-d84c-4861-870c-10246eb57530" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_DirectorMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_710fbba4-f8bf-413c-b4d8-a4a63861569e" xlink:to="loc_srt_DirectorMember_c81f76fa-d84c-4861-870c-10246eb57530" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_bf4734b9-db34-4a30-b055-516c4bd90cda" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_41dc7f81-ea80-40fe-9466-2dfb24a12be8" xlink:to="loc_us-gaap_AwardTypeAxis_bf4734b9-db34-4a30-b055-516c4bd90cda" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_bf4734b9-db34-4a30-b055-516c4bd90cda_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_bf4734b9-db34-4a30-b055-516c4bd90cda" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_bf4734b9-db34-4a30-b055-516c4bd90cda_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_c91843c0-6910-4bf2-91ce-aecef678f90a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_bf4734b9-db34-4a30-b055-516c4bd90cda" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_c91843c0-6910-4bf2-91ce-aecef678f90a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_fa712a3e-6ba7-4031-9718-f1b31b804988" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_c91843c0-6910-4bf2-91ce-aecef678f90a" xlink:to="loc_us-gaap_RestrictedStockMember_fa712a3e-6ba7-4031-9718-f1b31b804988" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_IncentiveStockOptionsMember_f1b2e523-068c-4244-afae-aa23f410c504" xlink:href="cpix-20210930.xsd#cpix_IncentiveStockOptionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_c91843c0-6910-4bf2-91ce-aecef678f90a" xlink:to="loc_cpix_IncentiveStockOptionsMember_f1b2e523-068c-4244-afae-aa23f410c504" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityAxis_cd0a5b70-ff7b-4dc1-8255-7fc05e87e5e5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_41dc7f81-ea80-40fe-9466-2dfb24a12be8" xlink:to="loc_us-gaap_LineOfCreditFacilityAxis_cd0a5b70-ff7b-4dc1-8255-7fc05e87e5e5" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityLenderDomain_cd0a5b70-ff7b-4dc1-8255-7fc05e87e5e5_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityLenderDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LineOfCreditFacilityAxis_cd0a5b70-ff7b-4dc1-8255-7fc05e87e5e5" xlink:to="loc_us-gaap_LineOfCreditFacilityLenderDomain_cd0a5b70-ff7b-4dc1-8255-7fc05e87e5e5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityLenderDomain_b1874aba-29cf-4026-bf29-9e9098194f28" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityLenderDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LineOfCreditFacilityAxis_cd0a5b70-ff7b-4dc1-8255-7fc05e87e5e5" xlink:to="loc_us-gaap_LineOfCreditFacilityLenderDomain_b1874aba-29cf-4026-bf29-9e9098194f28" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_PinnacleBankMember_aca55c95-33f0-41d2-93f8-44354c26b34b" xlink:href="cpix-20210930.xsd#cpix_PinnacleBankMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLenderDomain_b1874aba-29cf-4026-bf29-9e9098194f28" xlink:to="loc_cpix_PinnacleBankMember_aca55c95-33f0-41d2-93f8-44354c26b34b" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cumberlandpharma.com/role/ShareholdersEquityandDebtDebtDetails" xlink:type="simple" xlink:href="cpix-20210930.xsd#ShareholdersEquityandDebtDebtDetails"/>
  <link:definitionLink xlink:role="http://www.cumberlandpharma.com/role/ShareholdersEquityandDebtDebtDetails" xlink:type="extended" id="ie57126931e58445e89c8a08ae64ab57d_ShareholdersEquityandDebtDebtDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityLineItems_107d8361-6c54-4f69-82ff-ae58438b3065" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_4342889b-966b-49b2-a0d0-a0209fd6d59c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_107d8361-6c54-4f69-82ff-ae58438b3065" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_4342889b-966b-49b2-a0d0-a0209fd6d59c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_LineOfCreditFacilityMaximumBorrowingCapacityIncreaseAmount_b15a0fc3-1dd8-4590-b882-1c6b5fc45389" xlink:href="cpix-20210930.xsd#cpix_LineOfCreditFacilityMaximumBorrowingCapacityIncreaseAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_107d8361-6c54-4f69-82ff-ae58438b3065" xlink:to="loc_cpix_LineOfCreditFacilityMaximumBorrowingCapacityIncreaseAmount_b15a0fc3-1dd8-4590-b882-1c6b5fc45389" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_LineOfCreditFacilityMaximumBorrowingCapacityTotalCapacity_0411c40d-3134-458d-9a69-815c52a7e0c8" xlink:href="cpix-20210930.xsd#cpix_LineOfCreditFacilityMaximumBorrowingCapacityTotalCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_107d8361-6c54-4f69-82ff-ae58438b3065" xlink:to="loc_cpix_LineOfCreditFacilityMaximumBorrowingCapacityTotalCapacity_0411c40d-3134-458d-9a69-815c52a7e0c8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_22d0e154-ec5d-40b7-96df-ed7ae7b5f597" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_107d8361-6c54-4f69-82ff-ae58438b3065" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_22d0e154-ec5d-40b7-96df-ed7ae7b5f597" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_3502b971-58b5-484a-996d-f56df0013cfc" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_107d8361-6c54-4f69-82ff-ae58438b3065" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_3502b971-58b5-484a-996d-f56df0013cfc" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage_5a321987-37bf-48e5-8a47-082f153f030f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_107d8361-6c54-4f69-82ff-ae58438b3065" xlink:to="loc_us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage_5a321987-37bf-48e5-8a47-082f153f030f" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_TheCoronavirusAidReliefAndEconomicSecurityActLoanProceedsReceived_cc8ecf62-dd77-4011-9a81-87d2e3da5973" xlink:href="cpix-20210930.xsd#cpix_TheCoronavirusAidReliefAndEconomicSecurityActLoanProceedsReceived"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_107d8361-6c54-4f69-82ff-ae58438b3065" xlink:to="loc_cpix_TheCoronavirusAidReliefAndEconomicSecurityActLoanProceedsReceived_cc8ecf62-dd77-4011-9a81-87d2e3da5973" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermLineOfCredit_4d15000e-ff90-49dc-b56d-4e2dc6257ec7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongTermLineOfCredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_107d8361-6c54-4f69-82ff-ae58438b3065" xlink:to="loc_us-gaap_LongTermLineOfCredit_4d15000e-ff90-49dc-b56d-4e2dc6257ec7" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures_a4e49abf-46a3-44d7-82d5-edc64d35e2fc" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_107d8361-6c54-4f69-82ff-ae58438b3065" xlink:to="loc_us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures_a4e49abf-46a3-44d7-82d5-edc64d35e2fc" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_47b529f0-bd21-4b1d-943b-5af2709f30ba" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_107d8361-6c54-4f69-82ff-ae58438b3065" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_47b529f0-bd21-4b1d-943b-5af2709f30ba" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityTable_01c9923a-72fd-45af-ac69-a5257d0f792e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_107d8361-6c54-4f69-82ff-ae58438b3065" xlink:to="loc_us-gaap_LineOfCreditFacilityTable_01c9923a-72fd-45af-ac69-a5257d0f792e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityAxis_6864e921-e812-4edd-873e-8260d55a21f7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_01c9923a-72fd-45af-ac69-a5257d0f792e" xlink:to="loc_us-gaap_LineOfCreditFacilityAxis_6864e921-e812-4edd-873e-8260d55a21f7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityLenderDomain_6864e921-e812-4edd-873e-8260d55a21f7_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityLenderDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LineOfCreditFacilityAxis_6864e921-e812-4edd-873e-8260d55a21f7" xlink:to="loc_us-gaap_LineOfCreditFacilityLenderDomain_6864e921-e812-4edd-873e-8260d55a21f7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityLenderDomain_d92cf7c3-acf0-445d-91b4-98ece5460a4d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityLenderDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LineOfCreditFacilityAxis_6864e921-e812-4edd-873e-8260d55a21f7" xlink:to="loc_us-gaap_LineOfCreditFacilityLenderDomain_d92cf7c3-acf0-445d-91b4-98ece5460a4d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_PinnacleBankMember_9426523c-ee34-44cb-9b21-e8ee279e6bda" xlink:href="cpix-20210930.xsd#cpix_PinnacleBankMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLenderDomain_d92cf7c3-acf0-445d-91b4-98ece5460a4d" xlink:to="loc_cpix_PinnacleBankMember_9426523c-ee34-44cb-9b21-e8ee279e6bda" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_cc405239-fcb9-47f7-9cf9-039cbdb4c098" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_01c9923a-72fd-45af-ac69-a5257d0f792e" xlink:to="loc_us-gaap_DebtInstrumentAxis_cc405239-fcb9-47f7-9cf9-039cbdb4c098" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_cc405239-fcb9-47f7-9cf9-039cbdb4c098_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_cc405239-fcb9-47f7-9cf9-039cbdb4c098" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_cc405239-fcb9-47f7-9cf9-039cbdb4c098_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_bbf31dc4-f31a-4748-9d12-c3ba40937f45" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_cc405239-fcb9-47f7-9cf9-039cbdb4c098" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_bbf31dc4-f31a-4748-9d12-c3ba40937f45" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_8de6865d-d462-41cd-af3e-15f891b60a13" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_bbf31dc4-f31a-4748-9d12-c3ba40937f45" xlink:to="loc_us-gaap_LineOfCreditMember_8de6865d-d462-41cd-af3e-15f891b60a13" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_FifthAmendmentMember_bbea2c9b-79d3-445d-a3ca-aaccf7d2c846" xlink:href="cpix-20210930.xsd#cpix_FifthAmendmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_bbf31dc4-f31a-4748-9d12-c3ba40937f45" xlink:to="loc_cpix_FifthAmendmentMember_bbea2c9b-79d3-445d-a3ca-aaccf7d2c846" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_e9f6b071-ea2f-4d19-9f4e-86307cb14ddd" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_01c9923a-72fd-45af-ac69-a5257d0f792e" xlink:to="loc_us-gaap_CreditFacilityAxis_e9f6b071-ea2f-4d19-9f4e-86307cb14ddd" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_e9f6b071-ea2f-4d19-9f4e-86307cb14ddd_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_e9f6b071-ea2f-4d19-9f4e-86307cb14ddd" xlink:to="loc_us-gaap_CreditFacilityDomain_e9f6b071-ea2f-4d19-9f4e-86307cb14ddd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_af38b56e-af38-48bb-8364-72b3186bbee3" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_e9f6b071-ea2f-4d19-9f4e-86307cb14ddd" xlink:to="loc_us-gaap_CreditFacilityDomain_af38b56e-af38-48bb-8364-72b3186bbee3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_95918447-3505-47af-ad1b-0592d35373b6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_af38b56e-af38-48bb-8364-72b3186bbee3" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_95918447-3505-47af-ad1b-0592d35373b6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_37e49cb7-02f9-4b86-b101-165a22600ed8" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_01c9923a-72fd-45af-ac69-a5257d0f792e" xlink:to="loc_srt_RangeAxis_37e49cb7-02f9-4b86-b101-165a22600ed8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_37e49cb7-02f9-4b86-b101-165a22600ed8_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_37e49cb7-02f9-4b86-b101-165a22600ed8" xlink:to="loc_srt_RangeMember_37e49cb7-02f9-4b86-b101-165a22600ed8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_7a943b86-710f-4c02-94a4-ba6342b423a5" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_37e49cb7-02f9-4b86-b101-165a22600ed8" xlink:to="loc_srt_RangeMember_7a943b86-710f-4c02-94a4-ba6342b423a5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_58342083-abf1-44ec-88f7-c13fc3267a80" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_7a943b86-710f-4c02-94a4-ba6342b423a5" xlink:to="loc_srt_MinimumMember_58342083-abf1-44ec-88f7-c13fc3267a80" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_ea1f666b-786a-4341-8820-986b3dc0ec6b" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_7a943b86-710f-4c02-94a4-ba6342b423a5" xlink:to="loc_srt_MaximumMember_ea1f666b-786a-4341-8820-986b3dc0ec6b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateAxis_bfdfb4ef-0c0b-47f0-bd51-0f4cd6edaf10" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_VariableRateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_01c9923a-72fd-45af-ac69-a5257d0f792e" xlink:to="loc_us-gaap_VariableRateAxis_bfdfb4ef-0c0b-47f0-bd51-0f4cd6edaf10" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_bfdfb4ef-0c0b-47f0-bd51-0f4cd6edaf10_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_bfdfb4ef-0c0b-47f0-bd51-0f4cd6edaf10" xlink:to="loc_us-gaap_VariableRateDomain_bfdfb4ef-0c0b-47f0-bd51-0f4cd6edaf10_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_9f544c4e-7e90-4a11-8f60-9d1e9aba05a7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_bfdfb4ef-0c0b-47f0-bd51-0f4cd6edaf10" xlink:to="loc_us-gaap_VariableRateDomain_9f544c4e-7e90-4a11-8f60-9d1e9aba05a7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LondonInterbankOfferedRateLIBORMember_f5d724d4-b1b7-422d-98c9-5860decfec72" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LondonInterbankOfferedRateLIBORMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_9f544c4e-7e90-4a11-8f60-9d1e9aba05a7" xlink:to="loc_us-gaap_LondonInterbankOfferedRateLIBORMember_f5d724d4-b1b7-422d-98c9-5860decfec72" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_a3b1fa9d-4cf7-4b7e-a15d-3b8cf5214470" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_01c9923a-72fd-45af-ac69-a5257d0f792e" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_a3b1fa9d-4cf7-4b7e-a15d-3b8cf5214470" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_a3b1fa9d-4cf7-4b7e-a15d-3b8cf5214470_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_a3b1fa9d-4cf7-4b7e-a15d-3b8cf5214470" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_a3b1fa9d-4cf7-4b7e-a15d-3b8cf5214470_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_1b4f56ad-9040-494c-b289-ae859ad917ba" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_a3b1fa9d-4cf7-4b7e-a15d-3b8cf5214470" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_1b4f56ad-9040-494c-b289-ae859ad917ba" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertibleDebtMember_d831bec9-5b8a-483f-9710-600e88c1faa1" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConvertibleDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_1b4f56ad-9040-494c-b289-ae859ad917ba" xlink:to="loc_us-gaap_ConvertibleDebtMember_d831bec9-5b8a-483f-9710-600e88c1faa1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_41974df7-1702-4478-8286-3fc979ad0750" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_CounterpartyNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_01c9923a-72fd-45af-ac69-a5257d0f792e" xlink:to="loc_srt_CounterpartyNameAxis_41974df7-1702-4478-8286-3fc979ad0750" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_41974df7-1702-4478-8286-3fc979ad0750_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_41974df7-1702-4478-8286-3fc979ad0750" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_41974df7-1702-4478-8286-3fc979ad0750_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_ba476a30-0ed1-47b3-bce0-757a8d98986a" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_41974df7-1702-4478-8286-3fc979ad0750" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_ba476a30-0ed1-47b3-bce0-757a8d98986a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_WinHealthInvestmentSingaporeLtdDomain_f6a8060e-a0bf-4a73-b18a-df0d3777553c" xlink:href="cpix-20210930.xsd#cpix_WinHealthInvestmentSingaporeLtdDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_ba476a30-0ed1-47b3-bce0-757a8d98986a" xlink:to="loc_cpix_WinHealthInvestmentSingaporeLtdDomain_f6a8060e-a0bf-4a73-b18a-df0d3777553c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_735b1b51-6332-4d24-b5a6-497cfb878f10" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_01c9923a-72fd-45af-ac69-a5257d0f792e" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_735b1b51-6332-4d24-b5a6-497cfb878f10" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_735b1b51-6332-4d24-b5a6-497cfb878f10_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_735b1b51-6332-4d24-b5a6-497cfb878f10" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_735b1b51-6332-4d24-b5a6-497cfb878f10_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_675fa301-8020-4ef1-9e39-0531b0875be7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_735b1b51-6332-4d24-b5a6-497cfb878f10" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_675fa301-8020-4ef1-9e39-0531b0875be7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_87926cf0-c5a8-4783-9759-8a912f95af1a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_675fa301-8020-4ef1-9e39-0531b0875be7" xlink:to="loc_us-gaap_SubsequentEventMember_87926cf0-c5a8-4783-9759-8a912f95af1a" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cumberlandpharma.com/role/IncomeTaxesDetailsTextual" xlink:type="simple" xlink:href="cpix-20210930.xsd#IncomeTaxesDetailsTextual"/>
  <link:definitionLink xlink:role="http://www.cumberlandpharma.com/role/IncomeTaxesDetailsTextual" xlink:type="extended" id="ie423d75232c545b38dde00ca44b48be9_IncomeTaxesDetailsTextual">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxContingencyLineItems_2b9fa7b0-59ff-4c6e-8458-84e58541a496" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxContingencyLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLossCarryforwards_dc041ee2-e7fb-4b58-8b16-73fad793b169" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLossCarryforwards"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_2b9fa7b0-59ff-4c6e-8458-84e58541a496" xlink:to="loc_us-gaap_OperatingLossCarryforwards_dc041ee2-e7fb-4b58-8b16-73fad793b169" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxContingencyTable_12e749c2-0c29-434c-bf52-a0475ce44ac0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxContingencyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_2b9fa7b0-59ff-4c6e-8458-84e58541a496" xlink:to="loc_us-gaap_IncomeTaxContingencyTable_12e749c2-0c29-434c-bf52-a0475ce44ac0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityAxis_f82cd8d9-ea8d-4bd9-a01b-3925e3e0ca63" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxAuthorityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeTaxContingencyTable_12e749c2-0c29-434c-bf52-a0475ce44ac0" xlink:to="loc_us-gaap_IncomeTaxAuthorityAxis_f82cd8d9-ea8d-4bd9-a01b-3925e3e0ca63" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_f82cd8d9-ea8d-4bd9-a01b-3925e3e0ca63_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_f82cd8d9-ea8d-4bd9-a01b-3925e3e0ca63" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_f82cd8d9-ea8d-4bd9-a01b-3925e3e0ca63_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_13c626d2-9a2c-4fa7-aa11-4dcefbe71155" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_f82cd8d9-ea8d-4bd9-a01b-3925e3e0ca63" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_13c626d2-9a2c-4fa7-aa11-4dcefbe71155" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticCountryMember_f3ec2b82-7017-45e2-b743-54380977ea69" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DomesticCountryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_13c626d2-9a2c-4fa7-aa11-4dcefbe71155" xlink:to="loc_us-gaap_DomesticCountryMember_f3ec2b82-7017-45e2-b743-54380977ea69" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cumberlandpharma.com/role/AdditionsandReturnsofProductRightsNarrativeDetails" xlink:type="simple" xlink:href="cpix-20210930.xsd#AdditionsandReturnsofProductRightsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.cumberlandpharma.com/role/AdditionsandReturnsofProductRightsNarrativeDetails" xlink:type="extended" id="i20c93a90b4b247b39e45a0618edad295_AdditionsandReturnsofProductRightsNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_d8dec2bb-d3fa-4dde-b4f3-6296f7e75fe5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesGross_9c1a2f96-471d-456e-ab80-76d6f344d483" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_d8dec2bb-d3fa-4dde-b4f3-6296f7e75fe5" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesGross_9c1a2f96-471d-456e-ab80-76d6f344d483" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherPaymentsToAcquireBusinesses_42c4ef9e-6ea8-4026-b173-751816282868" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherPaymentsToAcquireBusinesses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_d8dec2bb-d3fa-4dde-b4f3-6296f7e75fe5" xlink:to="loc_us-gaap_OtherPaymentsToAcquireBusinesses_42c4ef9e-6ea8-4026-b173-751816282868" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_TieredRoyaltyPaymentsPercentage_7d7fe71d-78db-4b6a-92e7-6fbdd81abe94" xlink:href="cpix-20210930.xsd#cpix_TieredRoyaltyPaymentsPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_d8dec2bb-d3fa-4dde-b4f3-6296f7e75fe5" xlink:to="loc_cpix_TieredRoyaltyPaymentsPercentage_7d7fe71d-78db-4b6a-92e7-6fbdd81abe94" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_4c947c7b-a8c5-4ab8-8c75-4f62023e5331" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_d8dec2bb-d3fa-4dde-b4f3-6296f7e75fe5" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_4c947c7b-a8c5-4ab8-8c75-4f62023e5331" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferredLiabilitiesIncurred_c13db486-f28a-43f0-a8c5-3c47cb6bebfc" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferredLiabilitiesIncurred"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_d8dec2bb-d3fa-4dde-b4f3-6296f7e75fe5" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferredLiabilitiesIncurred_c13db486-f28a-43f0-a8c5-3c47cb6bebfc" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesAcquisitions_2dfdf1f2-5e47-4999-870f-25da027166c4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesAcquisitions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_d8dec2bb-d3fa-4dde-b4f3-6296f7e75fe5" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesAcquisitions_2dfdf1f2-5e47-4999-870f-25da027166c4" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueAcquisitions_5cd5359e-b410-455f-bc81-0bf641fa18bd" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueAcquisitions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_d8dec2bb-d3fa-4dde-b4f3-6296f7e75fe5" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueAcquisitions_5cd5359e-b410-455f-bc81-0bf641fa18bd" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_dadd1450-b296-4708-9488-b0b765216fcc" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_d8dec2bb-d3fa-4dde-b4f3-6296f7e75fe5" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_dadd1450-b296-4708-9488-b0b765216fcc" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfIntangibleAssets_93993c6c-dabe-4afe-97ed-ffcfb855715a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProceedsFromSaleOfIntangibleAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_d8dec2bb-d3fa-4dde-b4f3-6296f7e75fe5" xlink:to="loc_us-gaap_ProceedsFromSaleOfIntangibleAssets_93993c6c-dabe-4afe-97ed-ffcfb855715a" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ProceedsFromSaleOfIntangibleAssetsInstallmentPayment_2b94563c-3af2-4bb3-980a-d08fa6701ba1" xlink:href="cpix-20210930.xsd#cpix_ProceedsFromSaleOfIntangibleAssetsInstallmentPayment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_d8dec2bb-d3fa-4dde-b4f3-6296f7e75fe5" xlink:to="loc_cpix_ProceedsFromSaleOfIntangibleAssetsInstallmentPayment_2b94563c-3af2-4bb3-980a-d08fa6701ba1" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax_9a9f1ec0-c15a-4466-bfc2-d6a3d5f17cbe" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_d8dec2bb-d3fa-4dde-b4f3-6296f7e75fe5" xlink:to="loc_us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax_9a9f1ec0-c15a-4466-bfc2-d6a3d5f17cbe" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_20673524-8b4c-43bb-97aa-412ed7e82950" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_d8dec2bb-d3fa-4dde-b4f3-6296f7e75fe5" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_20673524-8b4c-43bb-97aa-412ed7e82950" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_310c4c54-a67c-4ea0-9ce2-0558ce1d9672" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_20673524-8b4c-43bb-97aa-412ed7e82950" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_310c4c54-a67c-4ea0-9ce2-0558ce1d9672" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_310c4c54-a67c-4ea0-9ce2-0558ce1d9672_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_310c4c54-a67c-4ea0-9ce2-0558ce1d9672" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_310c4c54-a67c-4ea0-9ce2-0558ce1d9672_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_559237ab-2ebb-4cd0-90d2-9ecb0f6b87ba" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_310c4c54-a67c-4ea0-9ce2-0558ce1d9672" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_559237ab-2ebb-4cd0-90d2-9ecb0f6b87ba" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_VIBATIVMember_0e55168e-d2e5-42e5-8203-c9e286e0ae59" xlink:href="cpix-20210930.xsd#cpix_VIBATIVMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_559237ab-2ebb-4cd0-90d2-9ecb0f6b87ba" xlink:to="loc_cpix_VIBATIVMember_0e55168e-d2e5-42e5-8203-c9e286e0ae59" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_MethotrexateMember_1518488e-ed09-4d1e-9ef3-1d35173e328d" xlink:href="cpix-20210930.xsd#cpix_MethotrexateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_559237ab-2ebb-4cd0-90d2-9ecb0f6b87ba" xlink:to="loc_cpix_MethotrexateMember_1518488e-ed09-4d1e-9ef3-1d35173e328d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_da3d62f9-c1f6-4a0d-abbf-c43ee51cca4a" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_CounterpartyNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_20673524-8b4c-43bb-97aa-412ed7e82950" xlink:to="loc_srt_CounterpartyNameAxis_da3d62f9-c1f6-4a0d-abbf-c43ee51cca4a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_da3d62f9-c1f6-4a0d-abbf-c43ee51cca4a_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_da3d62f9-c1f6-4a0d-abbf-c43ee51cca4a" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_da3d62f9-c1f6-4a0d-abbf-c43ee51cca4a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_270d9c0e-fa4a-4b7c-b301-e2e484aaeb6b" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_da3d62f9-c1f6-4a0d-abbf-c43ee51cca4a" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_270d9c0e-fa4a-4b7c-b301-e2e484aaeb6b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ClinigenHealthcareLimitedMember_f2507615-d2bc-4876-ba61-957136b2a54c" xlink:href="cpix-20210930.xsd#cpix_ClinigenHealthcareLimitedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_270d9c0e-fa4a-4b7c-b301-e2e484aaeb6b" xlink:to="loc_cpix_ClinigenHealthcareLimitedMember_f2507615-d2bc-4876-ba61-957136b2a54c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_05d54064-360d-4db8-bae2-91d4d395ae72" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_20673524-8b4c-43bb-97aa-412ed7e82950" xlink:to="loc_us-gaap_AwardTypeAxis_05d54064-360d-4db8-bae2-91d4d395ae72" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_05d54064-360d-4db8-bae2-91d4d395ae72_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_05d54064-360d-4db8-bae2-91d4d395ae72" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_05d54064-360d-4db8-bae2-91d4d395ae72_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_a30148bf-073f-49d7-832b-fe0dcfbb21d5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_05d54064-360d-4db8-bae2-91d4d395ae72" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_a30148bf-073f-49d7-832b-fe0dcfbb21d5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_bb345acd-2fb3-430f-9e10-86d8e893249a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_a30148bf-073f-49d7-832b-fe0dcfbb21d5" xlink:to="loc_us-gaap_RestrictedStockMember_bb345acd-2fb3-430f-9e10-86d8e893249a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_a7064d94-240e-4007-b5ef-bfaea09e4900" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BalanceSheetLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_20673524-8b4c-43bb-97aa-412ed7e82950" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_a7064d94-240e-4007-b5ef-bfaea09e4900" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_a7064d94-240e-4007-b5ef-bfaea09e4900_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_a7064d94-240e-4007-b5ef-bfaea09e4900" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_a7064d94-240e-4007-b5ef-bfaea09e4900_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_61ac4cd5-5856-473a-b95d-c6f63d95effa" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_a7064d94-240e-4007-b5ef-bfaea09e4900" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_61ac4cd5-5856-473a-b95d-c6f63d95effa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCurrentLiabilitiesMember_42c04725-0271-4d1e-8d37-a546c8bf8b98" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherCurrentLiabilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_61ac4cd5-5856-473a-b95d-c6f63d95effa" xlink:to="loc_us-gaap_OtherCurrentLiabilitiesMember_42c04725-0271-4d1e-8d37-a546c8bf8b98" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNoncurrentLiabilitiesMember_43dd8daf-1c8d-447e-9574-9fb2ec91c375" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherNoncurrentLiabilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_61ac4cd5-5856-473a-b95d-c6f63d95effa" xlink:to="loc_us-gaap_OtherNoncurrentLiabilitiesMember_43dd8daf-1c8d-447e-9574-9fb2ec91c375" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cumberlandpharma.com/role/AdditionsandReturnsofProductRightsChangeinConsiderationDetails" xlink:type="simple" xlink:href="cpix-20210930.xsd#AdditionsandReturnsofProductRightsChangeinConsiderationDetails"/>
  <link:definitionLink xlink:role="http://www.cumberlandpharma.com/role/AdditionsandReturnsofProductRightsChangeinConsiderationDetails" xlink:type="extended" id="ibf2a4a012fa649b1acd99e8b536466d8_AdditionsandReturnsofProductRightsChangeinConsiderationDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_c7d7c39f-2747-4349-8157-5084f6d99ab4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyAccrualRollForward_69719e0a-48c0-4796-8d5c-2b42027ad89a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LossContingencyAccrualRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_c7d7c39f-2747-4349-8157-5084f6d99ab4" xlink:to="loc_us-gaap_LossContingencyAccrualRollForward_69719e0a-48c0-4796-8d5c-2b42027ad89a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_907d8116-5347-41c8-b2d7-f03415937612" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyAccrualRollForward_69719e0a-48c0-4796-8d5c-2b42027ad89a" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_907d8116-5347-41c8-b2d7-f03415937612" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForRoyalties_121ee9c3-7bc9-491f-8e79-2c926aa6ef59" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsForRoyalties"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyAccrualRollForward_69719e0a-48c0-4796-8d5c-2b42027ad89a" xlink:to="loc_us-gaap_PaymentsForRoyalties_121ee9c3-7bc9-491f-8e79-2c926aa6ef59" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_ee318128-bf86-4927-8e67-51fdc5b47ff7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyAccrualRollForward_69719e0a-48c0-4796-8d5c-2b42027ad89a" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_ee318128-bf86-4927-8e67-51fdc5b47ff7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_BusinessCombinationContingentConsiderationEarnedAndAccruedInOperatingExpenses_ac1ee07e-698f-46a8-b06e-ec16d17c1e15" xlink:href="cpix-20210930.xsd#cpix_BusinessCombinationContingentConsiderationEarnedAndAccruedInOperatingExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyAccrualRollForward_69719e0a-48c0-4796-8d5c-2b42027ad89a" xlink:to="loc_cpix_BusinessCombinationContingentConsiderationEarnedAndAccruedInOperatingExpenses_ac1ee07e-698f-46a8-b06e-ec16d17c1e15" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_e049554e-8d44-4e09-bba3-7f63810708ce" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_430dbb52-e367-4e81-b9fd-a4c71bfa1577" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_c7d7c39f-2747-4349-8157-5084f6d99ab4" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_430dbb52-e367-4e81-b9fd-a4c71bfa1577" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_7e648ce0-f9b4-4737-8d54-25bf96ed4285" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_430dbb52-e367-4e81-b9fd-a4c71bfa1577" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_7e648ce0-f9b4-4737-8d54-25bf96ed4285" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_7e648ce0-f9b4-4737-8d54-25bf96ed4285_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_7e648ce0-f9b4-4737-8d54-25bf96ed4285" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_7e648ce0-f9b4-4737-8d54-25bf96ed4285_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1a447d0a-5e08-4530-bd4d-f58a112f826a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_7e648ce0-f9b4-4737-8d54-25bf96ed4285" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1a447d0a-5e08-4530-bd4d-f58a112f826a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_VIBATIVMember_3c730611-9292-4681-9abc-9973fbe40a2d" xlink:href="cpix-20210930.xsd#cpix_VIBATIVMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1a447d0a-5e08-4530-bd4d-f58a112f826a" xlink:to="loc_cpix_VIBATIVMember_3c730611-9292-4681-9abc-9973fbe40a2d" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cumberlandpharma.com/role/AdditionsandReturnsofProductRightsDissolutionPaymentsDetails" xlink:type="simple" xlink:href="cpix-20210930.xsd#AdditionsandReturnsofProductRightsDissolutionPaymentsDetails"/>
  <link:definitionLink xlink:role="http://www.cumberlandpharma.com/role/AdditionsandReturnsofProductRightsDissolutionPaymentsDetails" xlink:type="extended" id="i8f29be8322af466f882c541ec9191580_AdditionsandReturnsofProductRightsDissolutionPaymentsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_5ffaf73d-e852-4b6a-8166-b950defb28eb" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_27d02636-cbfb-4208-b0e4-bf1d6e6f3ef7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5ffaf73d-e852-4b6a-8166-b950defb28eb" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_27d02636-cbfb-4208-b0e4-bf1d6e6f3ef7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_874ee80e-526b-4260-8434-d695346293fa" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CostOfGoodsAndServicesSold"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5ffaf73d-e852-4b6a-8166-b950defb28eb" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_874ee80e-526b-4260-8434-d695346293fa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingAndMarketingExpense_176d68d4-abc5-412b-b5c1-941628452b93" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SellingAndMarketingExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5ffaf73d-e852-4b6a-8166-b950defb28eb" xlink:to="loc_us-gaap_SellingAndMarketingExpense_176d68d4-abc5-412b-b5c1-941628452b93" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity_96bb49e8-f2af-4ba7-a358-17a73cab9569" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5ffaf73d-e852-4b6a-8166-b950defb28eb" xlink:to="loc_us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity_96bb49e8-f2af-4ba7-a358-17a73cab9569" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_d5178dc6-a611-4ff8-a504-8d579dab36f5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5ffaf73d-e852-4b6a-8166-b950defb28eb" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_d5178dc6-a611-4ff8-a504-8d579dab36f5" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_9a4992ae-e38f-4cfd-955b-251316829cd8" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_CounterpartyNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_d5178dc6-a611-4ff8-a504-8d579dab36f5" xlink:to="loc_srt_CounterpartyNameAxis_9a4992ae-e38f-4cfd-955b-251316829cd8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_9a4992ae-e38f-4cfd-955b-251316829cd8_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_9a4992ae-e38f-4cfd-955b-251316829cd8" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_9a4992ae-e38f-4cfd-955b-251316829cd8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_23e661db-e953-4963-8450-a34584c2c841" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_9a4992ae-e38f-4cfd-955b-251316829cd8" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_23e661db-e953-4963-8450-a34584c2c841" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cpix_ClinigenHealthcareLimitedMember_39221abf-bb00-4648-9275-c66638c9b9f0" xlink:href="cpix-20210930.xsd#cpix_ClinigenHealthcareLimitedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_23e661db-e953-4963-8450-a34584c2c841" xlink:to="loc_cpix_ClinigenHealthcareLimitedMember_39221abf-bb00-4648-9275-c66638c9b9f0" xlink:type="arc" order="0"/>
  </link:definitionLink>
</link:linkbase>
