FDA: New Draft Guidance on Impurities in Antibiotics

In mid-April 2026, a new draft entitled 'Establishing Impurity Specifications for Antibiotics' was published on the FDA (Food and Drug Administration) website. Comments on this 'Guidance for Industry' can now be submitted until 22 June 2026. The document is intended to assist applicants and marketing authorisation holders in developing and implementing specifications for impurities that may occur in fermentatively and semi-synthetically produced antibiotics. This includes antibiotic medicinal products for new drug applications (NDAs) and abbreviated new drug applications (ANDAs), antibiotic active substances that have a DMF and are listed in NDAs and ANDAs for antibiotic medicinal products, and over-the-counter (OTC) monograph drugs.

The table of contents of the current draft is as follows:

TABLE OF CONTENTS
I. INTRODUCTION
II. BACKGROUND
III. DISCUSSION
     A. Listing of Impurities and Degradation Products in Specifications
     B. Analytical Procedures
     C. Establishing Acceptance Criteria for Impurities and Degradation Products
        1. New Drug Applications under 505(b)(1) and 505(b)(2) of the FD&C Act and Associated Type
            II Drug Substance Drug Master Files
        2. Abbreviated New Drug Applications under 505(j) of the FD&C Act and Associated Type II
            Drug Substance Drug Master Files
        3. Over-the-Counter Monograph Drugs under 505G of the FD&C Act
GLOSSARY

Here you can find the full draft and information on how to comment on this document.