BRIEFING

 Rufinamide. This proposal is based on the version of the monograph official as of May 1, 2020. On the basis of comments and supporting data received, it is proposed to revise the concentrations of the following solutions: System suitability stock solution, System suitability solution, Standard stock solution, Standard solution, Sample stock solution, and Sample solution under the Assay and test for Organic Impurities. Additionally, the following changes are proposed:

1. In the Assay:

   • Update the System suitability section using the Standard solution for the Tailing factor, and the Relative standard deviation requirements.

   • Revise the Suitability requirement for the Relative standard deviation to be consistent with Chromatography 〈621〉.

   • Revise the instruction for handling of the analytical solutions.

2. In the test for Organic Impurities:

   • Add the Sensitivity solution.

   • Revise the Suitability requirement section by: using the Standard solution for the Tailing factor, and the Relative standard deviation requirements; and adding the Signal-to-noise ratio requirement.

   • Add a table and Note in the System suitability section to present relative retention times as an aid in peak assignment.

   • Revise the calculation equation and the table in the Acceptance criteria section to provide the Relative Response Factor for rufinamide related compound A, and rufinamide related compound B.

   • In the Acceptance criteria, a reference to User-Determined Reporting Thresholds 〈477〉 has been added for user flexibility. For more information, please see the USP Compendial Notice "New Chapter 〈477〉 User-Determined Reporting Thresholds and its Implementation in USP−NF Monographs".

   • Revise the instruction for handling of the analytical solutions.

 The comment period for this revision ends November 30, 2024. In the absence of significant adverse comments, it is proposed to implement this revision via an Interim Revision Announcement with an official date of March 1, 2025.

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

 (SM4: R. Nguyen)

 Case ID—SUB-295