Advanced Compounding; How to Investigate Microbiological Excursions at a Sterile Compounding Facility.

Per United States Pharmacopeia Chapter <797>, effective November 1, 2023, uncovering non-conforming cleanroom microbiological conditions must be investigated thoroughly and in a timely manner. This article's objective is to outline the basic elements in investigating microbiological excursions at a sterile compounding facility, which models the use of an Ishakawa diagram to conduct a root cause investigation and discusses important concepts such as: product impact analysis, corrective and preventive action effectiveness checks, trend analysis, and investigational pitfalls to avoid. While this article focuses on investigating microbiological excursions, the concepts can be applied to investigating an out-of-range temperature, relative humidity, pressure differential, total particle count, or compounded sterile preparation failure.