Container Closure Integrity Test Method Development on Vials Stored at -80°C Using Headspace Carbon Dioxide Analysis

Area of Science:

• Pharmaceutical Packaging
• Material Science
• Analytical Chemistry

Background:

• Container closure integrity (CCI) is critical for pharmaceutical product stability, especially for vials stored at sub-zero temperatures (-80°C).
• Low temperatures impact vial sealing due to rubber stopper glass transition and differential thermal expansion of packaging components.
• Existing CCI tests at room temperature fail to detect transient leaks that reseal upon warming.

Purpose of the Study:

• To develop and validate novel methods for CCI testing of frozen vials.
• To detect leaks that occur specifically under cold storage conditions.
• To utilize carbon dioxide ingress as a leak indicator in product-filled vials with unmodified headspace.

Main Methods:

• Two distinct CCI testing methods were developed for frozen vials, employing carbon dioxide ingress.
• Method 1: Effusive flow detection, suitable for specific storage conditions.
• Method 2: Diffusive flow detection, designed for different gas flow dynamics.

Main Results:

• The effusive method detected defects ≥2 µm (laser-drilled) and ≥0.4-0.6 µm (microwire) in glass and plastic vials.
• The diffusive method detected defects ≥2 µm (laser-drilled) and ≥0.8-2.6 µm (microwire) in glass and plastic vials.
• The study also investigated the influence of product-defect interactions and storage duration on CCI.

Conclusions:

• The developed methods provide reliable CCI assessment for frozen pharmaceutical vials.
• These techniques effectively identify leaks missed by traditional room-temperature testing.
• The findings are crucial for ensuring the integrity of temperature-sensitive pharmaceutical products during cold chain storage and transport.