The interactions of hydrogen peroxide concentrations and surface temperatures were studied in an isolator using chemical and microbiological techniques. These tests verified commonly accepted theories of the gaseous properties of flash vaporized hydrogen peroxide which have recently been challenged.

The purpose of this paper was to revisit some essential validation aspects of sanitizing isolators with hydrogen peroxide gas in order to assist the industry in demonstrating reproducibility of the process under worst-case conditions.

The foundation of the theory and application of hydrogen peroxide gas sterilization is discussed, including examples of filling line sanitization and lyophilizer chamber deep vacuum sterilization. Click on the link to the Interpharm Press website to order this book.

Testing was performed on a prototype vial filler isolator at TL Systems Corp. in Minneapolis, MN to determine the feasibility of incorporating hydrogen peroxide gas sterilization into the system. Carrier sterilization, isolator aeration, and water fill residual data was presented

Physical limit testing is discussed, including a study of the relationship between particulate ingress through a mousehole at various operating pressure. A long-term (7-day) simulated media fill data (including environmental monitoring) reveals a very robust system for contamination control.

An initial case study for the application of hydrogen peroxide gas to an isolated filling line is reviewed in the initial design phase, denoting general principles and requirements for the system specifications.
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The importance of performing temperature distribution studies, the use of chemical and biological indicators in optimizing and verifying proper gas distribution, a technique to easily perform square-wave D-value determinations, and a means to quantitatively monitor aeration efficiency when using a prototype VHP1000 was reviewed.

A great deal of information is available in the literature on the relative resistance of microorganisms to aqueous hydrogen peroxide; however, the same cannot be said for hydrogen peroxide in the gaseous state. Bacillus stearothermophilus spores were found to be the most resistant to the sterilant and the presence of organic soil did not affect the ability of hydrogen peroxide gas to sterilize stainless surfaces.