Limiting Distributions of Resistances for Specific Radiation Sterilization Doses

• Activity Number: 186
• Type: Topic Contributed
• Date/Time: Monday, August 7, 2006 : 2:00 PM to 3:50 PM
• Sponsor: Biopharmaceutical Section
• Author(s): Harry Bushar*+
• Companies: U.S. Food and Drug Administration
• Keywords: distributions of resistances ; D10 value ; bioburden ; verification dose ; substantiation for sterilization ; sterilization dose

Abstract

The Association for the Advancement of Medical Instrumentation (AAMI) is developing a Technical Information Report (TIR) to allow substantiation for sterilization of health care products at certain specific radiation doses (15, 17.5, 20, 22.5, 25, 27.5, 30, 32.5, and 35 kGy). Using simulations, non-unique limiting distributions of resistances are found, which consist of a relatively high D10 value (dose required to achieve inactivation of 90% of the average Bioburden [population of viable microorganisms]) (occurring with 5% frequency) and a relatively low D10 (occurring with 95% frequency), where both high D10 and low D10 decrease with increasing Bioburden, while verification dose (radiation dose predicted to give a sterility assurance level (SAL) = 0.1 [probability of a single viable microorganism]) first increases and then decreases with increasing Bioburden and evolving distributions.