Buyers must ensure the manufacturer holds a valid GMP (Good Manufacturing Practice) certification, which is the gold standard for pharmaceutical production. Additionally, products should comply with international pharmacopoeia standards such as USP (United States Pharmacopeia), BP (British Pharmacopeia), or EP (European Pharmacopeia). For specific markets, verify CEP (Certificate of Suitability) or DMF (Drug Master File) availability to ensure the active pharmaceutical ingredient (API) meets quality benchmarks.