4H-1,3-Thiazin-2-amine, N-(2,6-dimethylphenyl)-5,6-dihydro-, monohydrochloridehydrochloride;
5,6-Dihydro-2-(2,6-xylidino)-4H−1,3-thiazine hydrochloride;
N-(2,6-Dimethylphenyl)-5,6-dihydro-4H-1,3-thiazin-2-amine hydrochloride [23076-35-9]
BRIEFING
Xylazine Hydrochloride. 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:
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Add the chemical structure and update the chemical names of Xylazine Hydrochloride in the Chemical Information section.
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Revise Identification A to allow the flexibility of using either 197A or 197K.
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Replace the TLC-based Identification B with the chromatographic retention time agreement from the Assay.
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In the Assay:
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In the Chromatographic system section,
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Delete the guard column as it is not necessary when testing the drug substance with the modern technology.
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Add the particle size of the analytical column and run time for clarity.
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Delete the Note with column rinse and storage information to give the user flexibility.
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In the System suitability section, add the requirement of tailing factor of "0.8–1.8" and change the %RSD from "NMT 2.0%" to "NMT 1.0%" to be consistent with the performance of the analytical instruments.
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Delete the nonspecific Melting Range or Temperature test as the other tests in the monograph can adequately monitor the quality of the drug substance.
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Update the storage condition in the Packaging and Storage section 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)
Correspondence Number—SUB-173