Closed Systems in CNC Space

This article published in the PDA Journal details a risk-based methodology designed to assign environmental classifications to the different operations in biopharmaceutical facilities manufacturing non-sterile (low bioburden) drug substance. The authors propose a formal risk assessment-based methodology that is applicable in the early design phase of new facilities and facilitates the fast selection of the environmental conditions required for the different process steps. The risk assessment describes the risk to product quality or patient safety from environmental contamination, and this is expressed in terms of impact, probability, and detectability. The assessment considers growth potential in terms of time, nutrients, and temperature; bioburden limit; level of closure of the system; and the ability of the process to detect contamination to assign an environmental classification. Because closure is a key factor in the methodology, the authors propose a practical definition of closed systems, building on existing International Society for Pharmaceutical Engineering guidance.