Chapter 55
Drug Product Development in the Pharmaceutical Industry
From molecule to marketed product
API and Drug Product
A drug substance is the active pharmaceutical ingredient (API) that produces pharmacological activity; it may be made by chemical synthesis, natural product recovery, enzymatic reaction, recombinant DNA technology, or fermentation. A new chemical entity (NCE) is a drug substance with unknown clinical, toxicologic, physical, and chemical properties that has not been approved for marketing in the US. A drug product is the finished dosage form (capsule, tablet, injectable) containing the API with excipients.
Excipients are inert ingredients that can modify release rate, improve stability, and mask taste. The type of development pathway depends on whether the product is an NCE, a line extension, a generic, or a specialty product.
API vs Drug Product
The API (drug substance) is the pharmacologically active component; the drug product is the finished dosage form containing the API plus excipients. Identity, strength, quality, and purity depend on proper control of the manufacturing and synthetic process.
📖 “API/drug substance: active component (chemical synthesis, natural product, enzymatic, recombinant DNA, fermentation). NCE: unknown properties, not approved in US. Drug product: finished dosage form (capsule/tablet/injectable) with API + excipients. Excipients modify release, stability, taste.”