BRIEFING

 Xylazine Injection. This proposal is based on the version of the monograph official as of May 1, 2020. On the basis of comments received, it is proposed to revise the Labeling section to indicate that it is for veterinary use only. Additionally, it is proposed to revise the monograph with the following changes:

1. Replace the use of 197U in Identification A with the UV spectra agreement from the Assay. Additionally, revise the Detector in the Assay to support the proposed Identification A.

2. Replace the TLC-based Identification B with the chromatographic retention time agreement from the Assay.

3. In the Assay:

   • Delete the filtration procedures in the Mobile phase, as it is general good lab practice, and in the Standard solution, as it is not necessary.

   • Revise the filtration procedure in the Sample solution and delete the Note with column rinse and storage information in the Chromatographic system section to give the user flexibility.

   • Add the column particle size and the run time for clarity.

   • Update the molecular weights of xylazine and xylazine hydrochloride in the Analysis section.

4. In the Specific Tests section:

   • Remove the numerical limit in the Bacterial Endotoxins Test and refer to Bacterial Endotoxins Test 〈85〉 for calculation of limits.

   • Add the test and requirements of Particulate Matter in Injections 〈788〉.

5. In the Additional requirements section, add the storage condition for clarity.

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

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

 (SM3: J. Li)

 Case ID—SUB-179