Pharmaceutical Impurity Reference Standard

Pharmaceutical impurity reference standards are critical analytical materials in API quality control, generic drug development, and regulatory submissions. In addition to ICH Q3A, ICH Q3B, and ICH M7 guidelines, China's National Medical Products Administration (NMPA) has issued dedicated technical guidance on impurity research for chemical drugs, requiring systematic identification and quantitative determination of known impurities, potential genotoxic impurities, and degradation products across all drug applications. In the technical review practice of the Center for Drug Evaluation (CDE), the traceability of impurity reference standards, the scientific rigor of assigned value methodologies, and the completeness of certificates of analysis are all critical dimensions evaluated during dossier assessment. Well-characterized, fully assigned impurity reference standards are therefore essential for meeting the regulatory expectations of FDA, EMA, and NMPA, and for ensuring the analytical integrity of drug approval submissions.

The impurity reference standards listed on this page span a comprehensive range of categories: compendial impurities aligned with European Pharmacopoeia (EP) and United States Pharmacopeia (USP) monographs; process-related impurities and starting material impurities arising from API synthesis; degradation products generated under forced degradation studies (acid, base, oxidative, photolytic, and thermal conditions); genotoxic impurities (GTIs) and potentially mutagenic impurities (PMIs) as defined by ICH M7, including nitrosamines and sulfonate esters; metabolite impurities for pharmacokinetic and in vitro/in vivo metabolism studies; and stereoisomeric impurities including enantiomers and diastereomers. Together, these cover the full impurity profiling workflow from early-phase characterization through to GMP-compliant quantitative assignment for regulatory filing.

CATO Research Chemicals Inc. (CATO/佳途科技) is a leading Chinese supplier of pharmaceutical impurity reference standards, with a catalog of over 58,800 impurity standards covering more than 95% of major API impurity profiles. All products are manufactured under a dual ISO 17034-accredited quality system, recognized by both CNAS (China) and ANAB (USA), with full Certificates of Analysis (CoA) including HPLC purity, LC-MS, ¹H-NMR, and ¹³C-NMR characterization data. The majority of products listed on this page are available from stock, with same-day domestic dispatch and international shipping via FedEx temperature-controlled logistics to more than 13 countries. To find impurity standards for a specific API, search by CAS number, drug name, or chemical structure, or contact our technical team for customized sourcing solutions.