The new version of Annex 1 of the EU GMP guidelines, The Rules Governing Medicinal Products in the European Union Volume 4, emphasizes the importance of quality risk management throughout the production process and its role in ensuring patient safety. Using integrity testing processes to confirm the quality of a sterilizing filter is a critical part of the processes within the aseptic manufacturing suite and should be included in any risk management process.
BioPhorum’s Sterile Filtration Quality Risk Management team wanted to explore current practices for calibrating and qualifying integrity test devices, detecting and investigating failure modes, and the impact of ‘false passed’ and ‘false failed’ results on the filter integrity testing process.
To this end, the team of process experts developed a survey to capture members’ experiences, and the results have been published in Sterile filtration integrity testing trends—industry survey findings.
Questions covered the areas of integrity tester calibration and qualification, training and investigation procedures, integrity testing processes, and cost implications.
The survey results suggest that a small number of respondents are employing additional practices for integrity testing, integrity tester performance qualifications (including detection of atypical results), training on integrity test unexpected events and use of instrument features to detect test errors.
It is possible that these elements will become accepted as integrity testing best practices as Annex 1 requirements are implemented. By working to standardize integrity testing practices and implementing the suggested practices described in the paper, process understanding will increase, costs will be reduced, and sterility assurance will increase.
Survey respondents have sterile filtration processes covering both clinical and commercial scale manufacture with batch sizes ranging from less than 10 liters to multiple thousands of liters and, therefore, include a range of commonly applied pressures, flow rates and fluids.
The paper includes appendices on common integrity test instrument error-detection features and a Venn diagram depicting possible results from an automated filter integrity test.