PT - JOURNAL ARTICLE AU - Agalloco, James P TI - The Bugs Don't Lie AID - 10.5731/pdajpst.2019.009894 DP - 2019 Jan 01 TA - PDA Journal of Pharmaceutical Science and Technology PG - pdajpst.2019.009894 4099 - http://journal.pda.org/content/early/2019/09/13/pdajpst.2019.009894.short 4100 - http://journal.pda.org/content/early/2019/09/13/pdajpst.2019.009894.full AB - Sterilization is a critical process in the preparation of many drug products. Its execution and validation are addressed in numerous regulatory, pharmacopeial and industry documents. EMA Annex 1: Sterile Medicinal Products stands alone in giving clear preference to physical measurements over those obtained from biological indicators. This paper reviews principles behind sterilization processes outlining the differences between physical and biological measurements, as well as their relationship to each other. The assumptions associated with the use of physical measurement are explored and their derivation from microbiological results is traced with the intent of re-affirming the primacy of biological evidence. The arguments and objections to the use of biological indicators in sterilization are reviewed and deconstructed.