Drug Substance

Active components of drug product

Drug Substance are defined in ICH Q7 Good Manufacturing Practice Guidance for Active Pharmaceutical Ingredients as "Any substance or mixture of substances intended to be used in the manufacture of a drug (medicinal) product and that, when used in the production of a drug, becomes an active ingredient of the drug product. Such substances are intended to furnish pharmacological activity or other direct effect in the diagnosis, cure, mitigation, treatment, or prevention of disease or to affect the structure and function of the body." Active Pharmaceutical Ingredients (API) and drug substance are considered synonyms.