Issue Date: April 20, 2026
Issued by: Center for Drug Evaluation and Research
Topic(s): Chemistry, Manufacturing, and Controls (CMC), Pharmaceutical Quality
Status: Draft

Establishing Impurity Specifications for Antibiotics

The Food and Drug Administration (FDA, Agency, or we) is announcing the availability of a draft guidance for industry entitled “Establishing Impurity Specifications for Antibiotics.” The draft guidance provides recommendations regarding the establishment of specifications for organic impurities in antibiotics manufactured by fermentation and semi-synthesis. This draft guidance applies to antibiotic drugs subject to approval under new drug applications (NDAs) and abbreviated new drug applications (ANDAs) and associated type II drug substance drug master files (DMFs) referenced in antibiotic NDAs and ANDAs. This guidance also applies to nonprescription antibiotic drugs, often referred to as over-the-counter (OTC) monograph drugs. By providing these recommendations, FDA intends to clarify effective control strategies, support the development of high-quality antibiotic products, and promote consistency in quality standards.

Download the Guidance Document