Diclofenac EP Impurity B, chemically defined as 2-[(2,6-Dichlorophenyl)amino]benzaldehyde and designated Diclofenac USP Related Compound B, is an aldehyde-type degradation impurity of Diclofenac, with molecular formula C₁₃H₉Cl₂NO and molecular weight 266.12 g/mol. This impurity is formed mainly through oxidative decarboxylation of the acetic acid side chain of the parent NSAID and is closely related to the corresponding benzylic alcohol (Diclofenac EP Impurity C), with which it shares the same degradation pathway under oxidative and photolytic stress. This makes it a key marker for oxidative degradation profiling, forced-degradation studies, and stability-indicating HPLC method development for Diclofenac Sodium and Diclofenac Potassium drug substances and formulations. Manufactured at Chemicea under precisely controlled synthetic and analytical protocols, this reference standard supports impurity identification, method validation (AMV), and quality-control testing in accordance with EP, BP, and USP requirements, and is routinely applied in ANDA and DMF regulatory filings. 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 pharmaceutical laboratories worldwide. CAS No. 22121-58-0 | Explore complete technical documentation, Safety Data Sheet (SDS), and pricing.