By Claudio Denoya, PhD, and Gilberto Dalmaso, PhD, Particle Measuring Systems
The recently revised United States Pharmacopoeia (USP) chapter <1116> Microbiological Control and Monitoring of Aseptic Processing Environments includes a thorough description, definitions and guidance on microbiological control and monitoring in aseptic processing environments (1). Chapter <1116> is arguably one of the most comprehensive informational chapters from the USP, and it is particularly challenging due to its proposal regarding measurement of microbial contamination based on Contamination Recovery Rates (CRR) rather than the conventional enumeration of colony forming units (cfu). Instead of using the microbial limits currently endorsed by aseptic guidances (2–4)—which are based on cfu—<1116> proposes CRR values expressed in maximum allowed percentage of contaminated samples. The proposal is generating a broad range of discussions among pharmaceutical professionals regarding potential implications of these changes.