Design and use of a novel peracetic acid sterilizer for absolute barrier sterility testing chambers

Increasing use is being made of absolute barrier chambers in the pharmaceutical industry for sterility testing of sterile pharmaceuticals. Since these barriers are designed to form a microbial-tight enclosure to eliminate laboratory microbial contamination derived from the operator and the environment,it is important that the method used to sterilize these barriers, product containers, and articles used within, provide a high degree of sterility assurance. A major part of incorporating absolute barriers in the sterility testing laboratory at the Upjohn Company was to design an automated sterilization system to facilitate the spraying of a liquid sterilant, e.g., peracetic acid, inside these barriers. This article focuses on general design considerations, specific details of the apparatus, and the operational steps. The sterilization efficacy of this method is also described, with particular emphasis on validation criteria and results. Finally, operational sterility testing results are discussed.