ABSTRACT
Cycle development studies are conducted in order to determine a sterilization cycle that will deliver the desired microbial lethality to a product while maintaining product functionality and package integrity. Ethylene oxide sterilization cycles used to be “hit-or-miss” propositions, in which the product load was literally gassed to death, aerated for an appropriate period of time and delivered to the marketplace. In development studies, a product is evaluated for factors that play a role in ethylene oxide sterilization. Microbial lethality of the cycle may be determined by one of two methods: the survivor curve construction method or the fraction-negative method. Survivor curve construction determines lethality of the sterilization cycle by directly enumerating the survivors of the microbial challenge system or the naturally occurring bioburden following cycle exposure. The natural product chosen for the testing should include that with the highest bioburden or design features that increase resistance to the sterilization process.
