<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>Used to associate the salt form of a drug with its free acid or free base.</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition>
nci:P98
The free acid or base is responsible for the drug's therapeutic effect. Hence, the salt form of a drug has the same mechanism of action as the free acid or base form.