Famotidine EP Impurity C, chemically known as 3-[[[2-[(Diaminomethylene)amino]thiazol-4-yl]methyl]sulfanyl]-N-sulfamoylpropanamide and designated Famotidine USP Related Compound C (Famotidine Sulfamoyl Propanamide), is an amide-type hydrolytic impurity of Famotidine, with molecular formula C₈H₁₄N₆O₃S₃ and molecular weight 338.42 g/mol (hydrochloride salt C₈H₁₄N₆O₃S₃·HCl, 374.88 g/mol). Structurally, this compound results from hydrolysis of the C=N bond of the N-sulfamoylpropanimidamide (sulfamoyl amidine) side chain of the parent H2-receptor antagonist into an N-sulfamoylpropanamide, a transformation typical of acid- and base-catalysed hydrolytic degradation. This makes it a key marker for hydrolytic degradation and stability monitoring of Famotidine drug substance and formulations. Manufactured at Chemicea under precisely controlled synthetic and purification protocols, this reference standard is essential for impurity identification, stability-indicating method development, method validation (AMV), and quality-control testing in accordance with EP, BP, and USP monograph requirements for Famotidine. Each batch is supplied with a comprehensive Certificate of Analysis supported by HPLC, ¹H-NMR, and Mass Spectrometry characterization data, ensuring dependable analytical traceability for regulatory submissions and ANDA/DMF filings. CAS No. 76824-17-4 (hydrochloride; free base CAS No. 106433-44-7) | Explore complete technical documentation, Safety Data Sheet (SDS), and pricing.