Measuring container closure integrity (CCI) of polymer–based containers and syringes is a challenge. Tracer gas leak detection (i.e., Helium-leak)—the method endorsed by USP <1207> (Package Integrity Evaluation – Sterile Products)—cannot be used directly, because gases permeate polymers. Helium permeates at a very high rate, in part due to its small size. As such, direct use of Helium-leak with a polymer-based system will result in a leak rate above that measured with a glass-based system, that may be misinterpreted as resultant from a non-integral system, but is actually from Helium permeation. To overcome this challenge, the use of special fixtures is needed. Two fixtures have been custom-designed and built. Figures 1 and 2 show the configurations for vials and syringes, respectively. For vials, a key consideration is integrity of the seal with elastomer stopper. The fixture comprises a compression fitting enabling insertion of the area of the seal in the vacuum chamber. A flow of Helium is maintained on the other side of the fixture. This fixture can be employed to evaluate integrity of vials/jars assembled by customers. For syringes, a key consideration is integrity of the plunger interface with syringe barrel. The fixture likewise comprises a compression fitting enabling insertion of the syringe within the vacuum chamber with a flow of Helium on the other side. For both fixtures, surface area of polymer within the vacuum chamber is minimized – assuring that measured Helium results from elastomer/polymer interface – not the polymer itself.
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