The effect of pressure differential on microbial penetration of a sterile medical device tray

A developmental need of the medical device industry is a body of knowledge regarding the required level of sensitivity for package integrity tests. As a result of this need, the objective of this research was twofold: (1) to create and verify a new methodology for whole-package microbial testing for medical device packages and (2) to examine the effect of pressure differential on microbial ingress in a sterile medical device tray.; The new method was a clear improvement over existing techniques because it reduced the chance of false positives that were commonly observed in the previous tests of integrity. The method involved aseptically filling sealed, sterile device packages with a known volume of an appropriate growth medium, exposing the packages to a microbial challenge, incubating the package and inspecting it for growth.; After creating and refining the test technique, further work explored the impact of pressure differential and a limited number of hole sizes (0, 10, and 100 micron) on microbial penetration. The specific pressure differential examined simulates the descent of an aircraft from 8000 feet or a ground shipment descending from 8000 feet. While air transportation is a common mode for medical device distribution, it is important to recognize that packages are routinely exposed to pressure differentials in all elements of handling.; Pressure differential and hole size had a statistically significant effect on the microbial penetration of the sterile medical device test tray used in this study. The critical penetration threshold is less than 100 microns. These results and the development and verification of a whole package microbial challenge test method provide useful information with which to build future research that seeks to determine the required level of sensitivity for packaging integrity tests for sterile packaging.