Environmental monitoring is an important part of quality assurance for the production environments of sterile pharmaceutical products. Especially for aseptic filling lines where products are filled without a terminal sterilization step, it is of utmost importance for product safety and thus an essential part of the quality control strategy. Such ISO 5 graded manufacturing environments are required to have < 1 colony-forming unit (CFU) per m³ of air.
A typical method for monitoring contamination of air is to actively draw air and filter it through special gelatin filters.
According to Annex 1 to the EU GMP guide, a minimum sample volume of 1 m³ of air should be taken per sample location. Considering, an 8 hours work shift 1 m3 is a too low sample volume to reliably judge the air quality of the manufacturing environment. One approach to improve product safety would be the implementation of a continuous air monitoring covering the complete production process (at multiple sampling points).
Unlike agar plates, which would dry out during long-term sampling, the Gelatin membrane filters can be used for the whole 8 h period. Human intervention, such as change of agar plates, could then be avoided, thus lowering the risk of secondary contaminations to nearly zero.
Explore results from a study aimed to establish whether a continuous sampling (and multisampling point assay) provides effective monitoring for the entire production process (8 h) by determining whether trapped organisms can withstand long-term drying stress with unaltered recovery.