When sourcing Famotidine as an Active Pharmaceutical Ingredient (API), it is critical to ensure it meets international pharmacopeia standards such as USP (United States Pharmacopeia), BP (British Pharmacopeia), or EP (European Pharmacopoeia). Buyers should verify the purity levels (typically ≥98.5%), the assay results, and the impurity profile via a Certificate of Analysis (CoA). Additionally, ensure the product is manufactured in a facility with GMP (Good Manufacturing Practice) certification to guarantee consistent quality and safety.