Active Ingredient

API

Definition

The component of a drug product that produces the intended therapeutic effect. The active pharmaceutical ingredient (API) is what the drug does — everything else in the formulation (binders, fillers, coatings) are inactive ingredients (excipients).

Example

In Tylenol Extra Strength, the active ingredient is acetaminophen 500 mg per tablet. The remaining mass consists of excipients.

Related Terms

Excipient Generic Equivalence Inactive Ingredient

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