Single-use solutions for PUPSIT: requirements, challenges, and solutions.

Pre-use post-sterilization integrity testing (PUPSIT) has emerged as a critical standard in biopharmaceutical manufacturing, driven by the revised EU GMP Annex 1 and global regulatory harmonization. PUPSIT aims to verify the integrity of sterilized filters before use, reducing the risks of defect masking and safeguarding drugs against contamination. However, implementing PUPSIT introduces significant technical and operational challenges, including more complex wetting and venting procedures that may bring increased risk of contamination and susceptibility to human error. This review outlines regulatory requirements and risk-based rationales for the PUPSIT evaluation process and discusses the integration of PUPSIT within a broader contamination control strategy. Design strategies for single-use systems emphasize simplicity, error-proofing, and effective wetting and flushing methods. A comparative analysis of single-use PUPSIT systems including manual, shadowboard-assisted, and automated PUPSIT systems illustrates how process flexibility, consistency, and safety can be achieved. Ultimately, successful PUPSIT implementation requires a balance of compliance, operational efficiency, and environmental stewardship, supported by documented risk assessments and validated process controls.