Type of Posting: Notice of Intent to Revise
Posting Date: 25-Apr-2025
Targeted Official Date: 01-Mar-2026; Interim Revision Announcement
Expert Committee: Simple Excipients Expert Committee
In accordance with the Rules and Procedures of the Council of Experts, this is to provide notice that the Simple Excipients Expert Committee (SE EC) intends to revise the Isopropyl Alcohol and Azeotropic Isopropyl Alcohol monographs.
On July 30, 2021, the SE EC published the Isopropyl Alcohol Revision Bulletin and Azeotropic Isopropyl Alcohol Revision Bulletin to include the Limit of Methanol test in the Identification section and to update the Limit of Volatile Impurities and/or Assay methods. Due to these revisions, it is necessary to prepare the System Suitability Solution by adding 200 µL/L methanol and 1000 µL/L ethyl acetate to the existing USP 2-Propanol System Suitability RS because the currently official USP 2-Propanol System Suitability RS only contains isopropyl alcohol with five (5) impurities, including 0.1% each of ethyl ether, acetone, diisopropyl ether, 1-propanol, and 2-butanol.
In response to feedback to reduce the burdens of stakeholders in terms of cost and time, USP has prepared and qualified a new replacement lot of USP 2-Propanol System Suitability RS that contains isopropyl alcohol with seven (7) impurities - approximately 0.1% each of ethyl ether, acetone, diisopropyl ether, 1-propanol, 2-butanol, ethyl acetate and 0.02% of methanol. Due to composition changes, the SE EC has determined that Isopropyl Alcohol and Azeotropic Isopropyl Alcohol monographs must be revised.
It is anticipated that the proposed revisions will be published as Interim Revision Announcements (IRA) in Pharmacopeial Forum 51(5) [Sep.-Oct. 2025] pursuant to the Rules and Procedures of the Council of Experts. If published as anticipated, the comment period for this revision would end on November 30, 2025, and the proposed IRA would become official on March 1, 2026.
Please note:
- The new replacement lot of USP 2-Propanol System Suitability RS (containing methanol and ethyl acetate) would not be suitable for use with the currently official monographs.
- The current lot of USP 2-Propanol System Suitability RS (which lacks methanol and ethyl acetate) will no longer be suitable for use once the IRA revisions become official, as anticipated on March 1, 2026.
USP intends to send out a customer communication letter to inform users of the USP 2-Propanol System Suitability RS about the changes to the currently official RS and its valid use date. Please stay tuned.
Should you have any questions, please contact Jenny Liu, Senior Principal Scientist (jyl@usp.org).