USP Chapters <31> and <1331> on Volumetric Apparatus again Published for Comments

In the Pharmacopeial Forum, PF 51(1), two USP chapters related to volumetric apparatus were published for public comment.

Based on the comments received, the proposals previously published in PF 49(5) have been canceled and replaced with new suggestions.

The briefing notes for Chapter <31> Volumetric Apparatus indicate a couple of changes, which are the same points mentioned in the draft published in PF 49(5). In the body text, however, some wording has been revised for clarity and precision.

The briefing notes for Chapter <1331> Use and Calibration of Volumetric Apparatus state that the "new general chapter has been developed to provide guidelines on methods validating the original calibration of volumetric apparatus described in Volumetric Apparatus <31>, their appropriate usage, and for periodic recalibrations as needed."  The chapter contains the following sections:

• A scope with volumetric apparatus accuracy classes,
• the relevant public standards,
• user considerations,
• measurement considerations,
• calibration process,
• calculations,
• a glossary, useful references, and additional sources of information.

A chapter numbered below 1000 becomes applicable and compendially required respect where it is referenced in a monograph or another applicable general chapter numbered below 1000 or in general notices. General chapters numbered 1000 to 1999 are for informational purposes only. They are considered interpretive and are intended to provide information on, give definition to, or describe a particular subject.

Comments on both chapters can be submitted until 31 March 2025. The drafts are available via the USP website access point.