Revision of USP <781> Optical Rotation

In the current Pharmacopeial Forum, PF 47(3), a proposal of USP Chapter <781> Optical Rotation has been published for comments.

The proposal is based on the version of the monograph official as of December 1, 2017. According to the USP, the previous proposal in PF 46(3) has been canceled. The text has been revised to address comments received.

Besides minor editorial changes to update the chapter to the current USP style, the revisions to the chapter include the following:

• Clarifications concerning the equation for specific rotation were incorporated.
• A new section on Qualification of Polarimeters was added.
• The reported optical rotation using visual polarimeters and replicate measurements has been removed.

Comments on the chapter can be submitted from now on. The comment deadline is July 31, 2021.

The draft chapter USP <781> Optical Rotation can be viewed here. (Please note: a one-time registration is required to access the Pharmacopeial Forum.)