API

An active pharmaceutical ingredient (API) is defined in ICH Q7 as “any substance or mixture of substances intended to be used in the manufacture of a drug product and that, when used in the production of a drug, becomes an active ingredient in 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 are distinguishable from inactive pharmaceutical ingredients, commonly known as excipients or formulation aids.

The European Medicines Agency, and the US FDA have adopted the ICH Q7 definition of APIs.

Many other terms are used interchangeably with API. They include:

• active
• bulk pharmaceutical chemical
• drug substance
• active principle (especially for natural extracts)
• therapeutic ingredient