Barb Jacobs

Scientist, Analytical Lab Services

May 23, 2017

New Methods in Measuring CCI – Part 1: Helium-Leak for Polymer Systems

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.

 New-Methods-CCI-Prt-1-Figure-1    Methods in measuring CCI Syringe

Figure 1                                                             Figure 2

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.

West Analytical Laboratory Services is focused on staying at the forefront of CCI technology to help customers determine the appropriate testing strategy for their products. To learn more about West’s offerings, please visit the Analytical Lab Services section of our website.