INTRODUCTION

Sterilization relies on the reliable destruction of microorganisms present in/on the materials being sterilized. Information regarding the resistance of the bioburden to the sterilization process (with the possible exception of overkill processes) is essential to confirm the efficacy of the sterilization process (see Sterilization of Compendial Articles 〈1229〉) and is also a required component of a parametric release program (1,2). Spores exhibit inherent and varying levels of resistance to all modalities of sterilization. There are limited resistance data available for some spore-forming and pathogenic microorganisms; however, for the vast majority of microorganisms (including most spores), there is no data available regarding their susceptibility to sterilization processes when present in or on pharmaceutical articles (3). Furthermore, wild type microorganisms and spores derived from manufacturing processes are likely distinct from their reference-standard culture-collection counterparts and may exhibit differing levels of resistance to sterilization processes (3). This chapter outlines methods that can be used to determine the presence of spores and the resistance of microorganisms, spores, and biologic indicators (BIs) to moist heat sterilization, including variations of the boil test mentioned in Moist Heat Sterilization of Aqueous Liquids 〈1229.2〉 and Monitoring of Bioburden 〈1229.3〉. The methods included in this chapter are not intended for use in radiation sterilization where the procedures described in ISO 11137 are to be followed (4).