USP Issues Draft Revision of Chapter <1231> on Pharmaceutical Water

The U.S. Pharmacopeia (USP) has released a draft revision of Chapter <1231> “Water for Pharmaceutical Purposes” in PF 51(4), open for comments until September 30, 2025. Key updates include clarification that ozone used for sanitization must be below detection limits before use, and a risk-based assessment is now required for additives.

Online monitoring of TOC (<643>) and conductivity (<645>) is recommended over offline methods. Simplified offline conductivity testing procedures and clearer guidance on TOC target limits and reference standards have also been added.

For sterile waters, new guidance clarifies "nominal container volume" and addresses TOC variations from packaging. A new section on nitrosamines advises risk-based evaluations and control strategies, as their removal can't be fully guaranteed by treatment alone.

The draft is freely accessible via the USP’s Pharmacopoeial Forum website with free registration.

09-07-2025