Container Closure Integrity of a Glass Prefillable Syringe in Deep Frozen Storage Conditions

Development of novel pharmaceutical drug modalities has created a need for frozen storage and transportation. Accurate and easy assessment of container closure integrity (CCI) in frozen conditions remains a challenge. Thus, container closure systems (CCS) suitable for low temperatures have been primarily restricted to vials despite the growing popularity of prefillable syringes (PFS) for parenteral administration. A new dye ingress test method, suitable for testing at low temperatures, was developed and applied to PFS across a range of deep-frozen temperatures. The method is versatile and can easily be extended to other common CCS formats over a wide range of temperatures including storage on dry ice (-80 °C). This new method was paired with an orthogonal technique, laser-based CO₂ headspace gas analysis, to evaluate the CCI of a glass PFS at temperatures from -50 °C to -80 °C. Both test methods showed comparable results and consistent CCI failure below a temperature of -70 °C. The primary mode of failure was the plunger-to-barrel interface, likely attributable to dimensional changes and loss of elasticity. This study demonstrates the temperature dependent CCI behavior of glass PFS and underscores the importance of thorough characterization of package integrity for deep frozen drug products.