PDA Letter Article

Process, Interrupted

by Fatima Hasanain, Polymer Materials Specialist, Nordion (Canada) Inc.


The Effect of Gamma Irradiation Process Interruption on Microbial Resistance of G. stearothermophilus

Sterilization process monitoring and control is key to product safety in the pharma industry. ISO/AAMI 11137-1 addresses the importance of monitoring radiation process parameters to ensure products have been processed according to specification. Radiation sterilization standards generally state that any doses delivered to product are cumulative, regardless of whether the dose is delivered all at once or whether there is a process interruption, such as correcting an is - sue with the conveyor system. That is certainly the case with regard to radiation effects on product. Whether or not multiple doses delivered with a process interruption in between doses are likewise cumulative with respect to microbial inactivation requires analysis. Although ISO/ AAMI 11137-1 describes the requirement to document process interruption, it does not include references to describe the effect of process interruption on microbial resistance to radiation.