BRIEFING

 Diclofenac Potassium. This proposal is based on the version of the monograph official as of September 1, 2021. It is proposed to revise the monograph with the following changes:

1. Update the chemical names of diclofenac potassium.

2. Revise Identification A to allow the flexibility of using either 197A or 197K.

3. Replace the UV spectroscopic procedure of Identification B with the retention time agreement, as obtained in the proposed Assay.

4. Replace the titration procedure in the Assay with an LC procedure that was validated using the Luna C8(2) brand of column with L7 packing. The typical retention time for diclofenac is about 12 min. The Acceptance criteria is revised from 99.0%–101.0% to 98.0%–102.0% to align with the assay procedure change from titration to liquid chromatography. The Definition is also revised accordingly.

5. In the Organic Impurities test:

   • Add the Sensitivity solution and the Signal-to-noise ratio requirement to support the proposed reporting threshold.

   • Add the particle size of the LC column based on supporting information.

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

   • In the Acceptance criteria, a reference to User-Determined Reporting Thresholds 〈477〉 has been added for user flexibility. Add a table to present the acceptance criteria.

6. Update the chemical information of USP Diclofenac Related Compound A RS in the USP Reference Standards section.

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

 (SM2: W. Yang)

 Case ID—SUB-267