Pre-filled syringes have become a leading format in pharmaceutical packaging due to advances in injectable drug development. Compared with traditional vials or ampoules, pre filled syringes are more complex, with multiple sealing points that must maintain integrity while enabling precise plunger movement. Handling, transport, and environmental factors further increase the complexity of container closure integrity evaluations. Helium leak testing, particularly using SIMS 1915+ technology from PTI, provides a highly sensitive and quantitative method to assess both individual seal points and the entire syringe system. This approach enables manufacturers to ensure reliable sealing and uphold the highest standards of safety and performance.
Key Functions of Plunger
The plunger in a pre-filled syringe serves two essential functions. First, it maintains a sterile barrier, preventing the ingress of contaminants such as microorganisms, oxygen, and moisture throughout the product shelf life. Second, it enables accurate and consistent drug delivery, requiring smooth and controlled movement without compromising seal integrity. Verifying these functions requires a leak testing technology capable of detecting extremely small defects that may not be identified through conventional methods. Using SIMS 1915+ technology, manufacturers can assess whether the plunger maintains its sealing performance under realistic conditions, ensuring sterility assurance while supporting functional performance requirements.
Typical Reasons for Seal Failures
Seal failures in pre-filled syringes can occur for multiple reasons. Common causes include improper material selection, dimensional inconsistencies, surface defects, or damage during assembly and transport. Misalignment or excessive force during filling and capping operations may create micro leaks that compromise integrity. Environmental factors such as temperature fluctuations during storage or shipment can further impact elastomer behavior and sealing performance. Advanced helium leak testing using SIMS 1915+ enables early identification of these failure mechanisms by detecting micro leaks with exceptional sensitivity, supporting root cause analysis and continuous process improvement.
Methods to Verify Seal Integrity
Helium leak testing with the SIMS 1915+ system is widely regarded as reliable CCI solution for evaluating syringe seal integrity. The system uses helium as an inert tracer gas to detect micro leaks with exceptional sensitivity. Helium is introduced into the test chamber or package, and a high sensitivity mass spectrometer measures any escaping gas. Custom tooling allows assessment of individual seal points, including plunger ribs, or evaluation of the entire syringe system as a whole, providing deterministic and reproducible results.
Key advantages of SIMS 1915+ technology include:
- Detection sensitivity down to 1 × 10?¹° mbar L s and below
- Quantitative data supporting statistical process control and trend analysis
- Ability to evaluate both component level and full system integrity
- Strong alignment with regulatory expectations for deterministic container closure integrity testing
Ensuring plunger integrity in pre-filled syringes requires a combination of precise engineering, rigorous testing, and structured quality assurance. Helium leak testing using SIMS 1915+ technology provides highly sensitive and quantitative detection of micro leaks, enabling manufacturers to validate seal integrity with confidence. When integrated with optimized design practices and controlled production processes, this deterministic testing approach helps pharmaceutical companies maintain the highest standards of safety, sterility, and performance in pre-filled syringe packaging.
