Helium leak testing of packages for oral drug products

This article presents an overview on what helium leak testing is and how it can be implemented as a test method to determine the tightness of packages for oral drug products in a quality control or development laboratory. Whereas earlier publications on helium leak testing mainly focused on testing vials and the correlation between helium leak rates and microbial ingress, this paper provides various examples how helium leak testing contributes to assure the integrity of containers for oral formulations. The results clearly show whether optimal tightness is achieved or an improvement in materials or the closing/sealing conditions should be envisaged. Helium leak testing using a flexible test chamber and a mass spectrometer as detector is of advantage in particular for flexible packages containing moisture and oxygen sensitive products, where a dye ingress test is not applicable and other detectors or methods might not be sensitive enough or give qualitative results only.