BRIEFING

 Isopropyl Alcohol. This proposal is based on the version of the monograph official as of December 1, 2023.

 In response to the letter from the U.S. Food and Drug Administration (FDA) on July 30, 2021, the Simple Excipients Expert Committee (SE EC) has published the Isopropyl Alcohol Revision Bulletin to include the Limit of Methanol test in the Identification section and to update the Assay and Limit of Volatile Impurities method. Due to these revisions, it is necessary to prepare the System suitability solution by adding 200 µL/L of methanol and 1000 µL/L of ethyl acetate to the existing USP 2-Propanol System Suitability RS because the current lot of USP 2-Propanol System Suitability RS only contains isopropyl alcohol with 0.1% each of ethyl ether, acetone, diisopropyl ether, 1-propanol, and 2-butanol.

 To reduce the cost and resources burden of stakeholders, USP has prepared and qualified a new replacement lot of USP 2-Propanol System Suitability RS that contains isopropyl alcohol with approximately 0.1% each of ethyl ether, acetone, diisopropyl ether, 1-propanol, 2-butanol, and ethyl acetate, and 0.02% of methanol. Due to composition changes in the new lot of USP 2-Propanol System Suitability RS, the currently official Isopropyl Alcohol monograph needs to be revised accordingly.

 Therefore, the SE EC proposes to revise the monograph through an accelerated revision process, Interim Revision Announcement (IRA), to make the following changes:

1. In the Assay, revise the System suitability solution preparation to USP 2-Propanol System Suitability RS.

2. In the USP Reference Standards section, update USP 2-Propanol System Suitability RS to include approximately 0.1% of ethyl acetate and 0.02% of methanol.

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

 The comment period for this revision ends on November 30, 2025. In the absence of any significant adverse comments, it is proposed to implement the changes via an Interim Revision Announcement with an official date of March 1, 2026. Similar revisions to the USP–NF Azeotropic Isopropyl Alcohol monograph will be published in the same PF 51(5) issue.

 Please note that the new lot of USP 2-Propanol System Suitability RS, which contains methanol and ethyl acetate, is not suitable for the current monograph. Conversely, 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 Isopropyl Alcohol IRA becomes effective on March 1, 2026. A customer communication letter will be posted on the USP store product page as the date approaches.

 (SE: J. Liu)

 Case ID—SUB-2247