Pamoic acid is primarily used in the pharmaceutical industry as a counterion in the formulation of drugs to improve their solubility, stability, and bioavailability. It is commonly employed to create pamoate salts of basic drugs, particularly those used in long-acting injectable formulations. For example, it is used in the production of pamoate salts of antipsychotic medications like paliperidone palmitate and antidepressant drugs such as imipramine pamoate. These formulations allow for controlled and sustained release of the active pharmaceutical ingredient, reducing the frequency of administration and improving patient compliance. Additionally, pamoic acid’s low solubility in water makes it suitable for creating depot injections, which slowly release the drug over an extended period. Its use in drug delivery systems highlights its importance in enhancing therapeutic efficacy and patient outcomes.