Examining the Effect of Secondary Packaging on Microbial Penetration into Sterile Medical Device Trays

Abstract

The relative efficacy of secondary packaging on the prevention of microbial ingress into sterile medical device trays was examined. Sterile device trays were aseptically filled with growth medium, exposed to microbial challenge, incubated, and inspected for growth. During microbial challenge, all package systems were subjected to a pressure differential that simulated those experienced during distribution. Penetration rates were significantly decreased (P = 0.01) when unlidded trays were packaged in pouches (0/39), compared to those in cartons (37/39). Similarly, the number of colony forming units (CFU) present was greater for unlidded trays packaged in cartons, compared to those in pouches (P = 0.03). To further explore the efficacy of cartons as a barrier to microbial ingress, lidded trays with a single 100 μm breach were packaged in cartons and subjected to the same methodologies; approximately 15% exhibited growth. When compared to unlidded trays, penetration rates (P<0.0001) and number of CFU decreased (P=0.0048). Microbial penetration was more prevalent for sterile trays packaged within cartons than in pouches. While folding cartons are not intended to perform as sterile barriers, this suggests that microbial penetration is more likely to occur for trays packaged within cartons than those in pouches.