5.1 Leaks in blister packs may affect product quality and such defects can arise from imperfections in the packaging material or bond between the sealed surfaces.

5.2 This method of leak testing is a useful tool as it allows non-destructive and non-subjective leak testing of blister packs. It allows the operator to evaluate how different packaging materials and packaging machine conditions affect the integrity of the packaging. It can also provide indication of unwanted changes in the packaging conditions.

5.3 This type of testing is typically used in pharmaceutical packaging production, during stability trials and for package research and development operations because of its non-destructive nature, cleanliness, and speed.

1.1 Test Packages—This test method can be applied to non-porous blister packs sealed with flexible films such as those used in pharmaceutical packaging. Such blister packs typically consist of thermoformed polymer or cold formed aluminum trays that contain a number of individual blister pockets into which tablets or capsules are placed. The trays are then sealed with a polymer, paper-backed or foil-based flexible laminate lidding material.

1.2 Leaks Detected—This test method detects leaks in blister packs by measuring the deflection of the blister pack surface in response to an applied vacuum. This deflection of the blister pack surface results from the difference in pressure between the gas inside the blister pack and the applied vacuum. Air loss from within a blister pocket as a result of a leak will alter this pressure differential causing a measureable variation in blister pocket deflection. This test method requires that the blister packs are held in appropriate tooling inside a suitable test chamber.

1.3 Test Results—Test results are reported qualitatively (pass/fail). Appropriate acceptance criteria for deflection, height, and collapse values are established by comparing non-leaking packs with those containing defects of a known size. Suitably sized defects in the laminate, tray material, and seal can be detected using this test method. The sensitivity of this test method depends upon a range of factors including blister pocket headspace, blister pocket size, lidding material type, lidding material thickness, lidding material tension, printing, surface texture, test conditions, and the values selected for the pass/fail acceptance criteria. The ability of the test to detect 15 µm, 50 µm, and catastrophic sized holes in four blister pack designs was demonstrated in a study.

1.4 The values stated in SI units are to be regarded as standard and no other units of measurement are included in this test method.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.