Board Certified Sterile Compounding Pharmacist (BCSCP) Practice Test 2026 - Free Sterile Compounding Pharmacist Practice Questions and Study Guide

The API is the substance intended for use in compounding that becomes the active ingredient with pharmacological activity. This means it is the specific drug component in a preparation that produces the therapeutic effect. Solvents, preservatives, and colorants do not have pharmacological activity themselves, so they are not considered the API—they’re inactive ingredients or excipients used to formulate, preserve, or identify the final product. For example, the active drug in a compounded suspension is the API, while the solvent or vehicle carries it, and any preservative or dye serves a supportive role rather than providing the therapeutic effect.