Propanimidamide, N’-(aminosulfonyl)-3-[({2-[(diaminomethylene)amino]-4-thiazolyl}methyl)thio]-;
{1-Amino-3-[({2-[(diaminomethylene)amino]-4-thiazolyl}methyl)thio]propylidene}sulfamide;
3-[[2-(Diaminomethyleneamino)thiazol-4-yl]methylthio]-N’-sulfamoylpropanimidamide [76824-35-6]
BRIEFING
Famotidine. This proposal is based on the version of the monograph official as of May 1, 2020. The primary purpose of this revision is to introduce the dimaleate salt form of USP Famotidine Related Compound B RS, in addition to the base form, in order to address improved material handling. Accordingly, the USP Reference Standards section is being revised to indicate that USP Famotidine Related Compound B RS may be available either as the free base form or as the dimaleate salt form. Additionally, it is proposed to revise the monograph with the following changes:
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Update the molecular weight of famotidine in the Chemical Information section to reflect the current USP Dictionary of USAN and International Drug Names.
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In the test for Organic Impurities:
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Add a Sensitivity solution for the assessment of the Signal-to-noise ratio in the Suitability requirements to align with the reporting threshold.
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Add the Relative standard deviation criterion for the Standard solution in the Suitability requirements to ensure system repeatability.
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Add a table and Note in the System suitability section to present relative retention times as an aid in peak assignment. Revise the table in the Acceptance criteria to list only the limits for specified impurities, any unspecified impurities, and total impurities.
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In the Acceptance criteria, add a reference to User-Determined Reporting Thresholds 〈477〉 for user flexibility. For more information about this change, please see the USP Compendial Notice "New Chapter 〈477〉 User-Determined Reporting Thresholds and its Implementation in USP–NF Monographs".
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In the USP Reference Standards section:
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Add the chemical name, formula, and molecular weight for the dimaleate salt form of USP Famotidine Related Compound B RS, in addition to the base form.
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Update the molecular weights for the base form of USP Famotidine Related Compound B RS, USP Famotidine Related Compound E RS, and USP Famotidine Related Compound F RS as per the current USP Dictionary of USAN and International Drug Names.
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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, 2026. In the absence of any significant adverse comments, it is proposed to implement this revision via an Interim Revision Announcement with an official date of May 1, 2027.
(SM3: R. Muppa)
Case ID—SUB-2037