Upcoming USP 661.1 And 661.2 Chapters: Differences, Requirements, And Compliance For Container Closures

The upcoming USP 661.1 and 661.2 chapters mark a significant shift in regulatory expectations for pharmaceutical packaging. Moving beyond the broad requirements of USP 661, these new standards provide a more detailed, risk-based framework to ensure patient safety and product integrity. USP 661.1 focuses on the characterization of individual plastic materials of construction, requiring comprehensive physicochemical and biocompatibility testing, as well as analysis of additives and residual substances. USP 661.2 addresses the entire container closure system, incorporating chemical suitability assessments through extractables and leachables testing, aligned with USP 1663 and 1664 guidelines.

Compliance with these chapters became mandatory on December 1, 2025, though early adoption was encouraged. Existing data may be leveraged, but no materials are grandfathered under the new requirements. Testing protocols include advanced analytical techniques such as infrared spectroscopy, differential scanning calorimetry, and chromatographic methods for additive detection. Acceptance criteria are stringent, but failures can be mitigated through risk assessments and chemical identification.

These changes reflect a broader industry trend toward rigorous, science-driven packaging evaluations. Organizations should begin preparing now to meet these standards and avoid compliance risks. Access the full resource to explore detailed requirements and implementation strategies.