Update of USP Chapter <1099> : Content Uniformity in Large Samples

A revised draft of USP General Chapter <1099>, titled "Limit on Number of Large Deviations When Assessing Content Uniformity in Large Samples," has been published in Pharmacopeial Forum PF 51(3). This update replaces the earlier proposal from PF 47(4), which was withdrawn due to public feedback. The revised version clarifies that <1099> operates independently of Chapter <905> (Uniformity of Dosage Units).

Key changes include the addition of a new Table 2 and relocation of statistical formulas to an appendix. The chapter outlines a statistical framework for evaluating content uniformity in large data sets, particularly when sample sizes exceed 30 units. It introduces a zero-tolerance criterion (ZTC) and incorporates a confidence interval-based method—specifically Jeffreys’ approach—to assess deviation limits.

These updates aim to provide manufacturers with clearer and more adaptable tools for quality assessment. The draft is available online, and public comments are welcome through July 31, 2025.

18-05-2025