Sterility Test Failure Investigation — Practical Examples and Lessons Learned
Sterility testing is one of the most critical quality control procedures in pharmaceutical microbiology. It ensures that parenteral, ophthalmic, and other sterile products are free from viable microorganisms. However, when a sterility test failure occurs, it raises serious questions about the integrity of the aseptic process, product quality, and GMP compliance. This article explains how to investigate sterility test failures through detailed, real-world examples and provides essential lessons learned for avoiding future occurrences. What is a Sterility Test? A sterility test is designed to demonstrate that a product or batch is free from viable microorganisms. It is performed using validated methods such as: Membrane Filtration Method: Preferred for aqueous and filterable products. Direct Inoculation Method: Used for oily, viscous, or non-filterable samples. The test follows pharmacopeial standards such as USP <71> , Ph. Eur. 2.6.1 , and IP 3.2.1 , and...