Bubble Test Medical Packaging
The Bubble Emission Test is a method of determining the integrity of medical packaging. Bubble testing involves the application of pressure to the underside of a submerged material.
There is a greater range of integrity / leak testing options for foil packages than there is for porous pouches and blisters. This testing is required by ISO 11607 as part of medical device design validation and quality assurance following sterilisation validation.
One option for this testing of protective barriers is ASTM F2096 Standard Test Method for Detecting Gross Leaks in Packaging by Internal Pressurization (Bubble Test).
Bubble test medical packaging testing is the same method that would be used for finding a puncture in a bicycle tyre. The packaging is held underwater and then a pressure difference is generated between the inside of the package and the outside atmosphere. As long as the pressure inside the package is greater than the outside pressure, bubbles will be visually observed from any leakage points. The pressure differential for the bicycle tyre is generated with a pump. For a medical device package testing a vacuum system can be used to lower the external pressure; alternatively, a pillow pack can be compressed to increase the internal pressure.
This method can be applied to vacuum packs, because if there is a leak, air will have entered a pack. However, a more sensitive trace gas test may be more reliable at detecting leaks in a vacuum pack.
More detailed information is available here.