FPGEE 2026 Practice Exam for NABP – The Complete All-in-One Guide to Exam Success!

The purpose of an active pharmaceutical ingredient (API) is to exert a pharmacological effect. An API is the part of any drug that is biologically active and is intended to provide the therapeutic effect for which the medication is used. It is the core component that interacts with the biological systems in the body to treat, prevent, or diagnose a condition. For example, in a pain relief medication, the API is the compound that blocks pain receptors or reduces inflammation, while other components of the formulation may support its delivery, stability, or shelf life.

In contrast, the other options describe roles that do not align with the definition of an API. Inactive components serve as excipients and do not contribute to the pharmacological effect. Enhancing the stability of medications and acting as preservatives are also functions performed by excipients rather than APIs. The distinction is important for understanding the formulation of drugs and the specific role each ingredient plays in achieving the desired therapeutic outcomes.