Glossarium

Active ingredients are the substances in drugs that are responsible for the beneficial health effects experienced by consumers (animals). The active ingredient in a pharmaceutical drug is called an active pharmaceutical ingredient (API). Health Canada

An active ingredient (AI) is the ingredient in a pharmaceutical drug or pesticide that is biologically active. The similar terms active pharmaceutical ingredient (API) and bulk active are also used in medicine, and the term active substance may be used for natural products. Wikipedia

Active Pharmaceutical Ingredient (API) refers to the chemical substance in a drug that has a biological and therapeutic (beneficial) effect. CDPQ Team