Pyrimethamine Impurity 4 CAS CATO-C4X-20444

Description

Under current pharmacopoeial and regulatory frameworks, quality-control requirements for this class of reference material explicitly involve the control of targets including Pyrimethamine Impurity 4.

CATO supplies Pyrimethamine Impurity 4 (CAS CATO-C4X-20444), a pharmacopoeial impurity reference standard (molecular formula C19H16Cl2N2O, MW 359.25 g/mol) used for the identification and quantification of trace impurities in APIs.

The molecular framework of Pyrimethamine Impurity 4 (C19H16Cl2N2O) is characterized by a steroid core, an amide group, a hydroxyl group, an ether linkage, chlorine substitution. In reversed-phase chromatography, its retention is governed primarily by its high hydrophobicity (logP), which provides a practical basis for HPLC-UV/DAD or LC-MS method development. The high carbon-to-hydrogen ratio imparts good lipophilicity, allowing liquid-liquid extraction with non-polar solvents such as n-hexane or ethyl acetate.

This reference standard supports related-substances testing and method development in line with ICH Q3A/Q3B guidance on impurity control, and is suitable for system suitability testing and forced-degradation studies.

The assigned purity is verified by mass-balance and quantitative NMR (qNMR) approaches, with the expanded uncertainty reported at a 95% confidence level (k=2). Batch homogeneity and stability are independently assessed for every lot.

Physical & Chemical Properties

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