BRIEFING

 Polyethylene Glycol 40 Castor Oil. This proposal is based on the version of the monograph official on December 1, 2024. This monograph includes a test for ethylene glycol and diethylene glycol (EG and DEG) in the Impurities section using a gas-chromatography (GC) method, based on the general chapter Ethylene Glycol, Diethylene Glycol, and Triethylene Glycol in Ethoxylated Substances 〈469〉. In response to a letter from the US FDA on February 10, 2023, the Complex Excipients Expert Committee is proposing to revise the current EG/DEG test method to be more user-friendly, and move the test from the Impurities section to the Identification section. The following are highlights of the changes made to this monograph:

1. Add the new Limit of Ethylene Glycol and Diethylene Glycol test in the Identification section as Identification C. This validated GC method is based on analyses using the Restek Rtx-Wax column equivalent to G16 phase. The typical retention times for diethylene glycol and ethylene glycol are 7.8 and 12.3 min, respectively.

2. In the Impurities section, delete the test for Ethylene Glycol, Diethylene Glycol, and Triethylene Glycol in Ethoxylated Substances.

3. Add USP Butane-1,3-diol RS, USP Diethylene Glycol RS, and USP Ethylene Glycol RS to the USP Reference Standards section.

 Additionally, minor editorial changes have been made to update the monograph to current USP style.

 The comment period for this revision will end on July 31, 2025. In the absence of any significant adverse comments, it is proposed to implement this revision via an Interim Revision Announcement with an official date of November 1, 2025.

 (CE: A. Chang)

 Case ID—SUB-585