When sourcing Ciprofloxacin, it is critical to ensure the supplier holds a valid GMP (Good Manufacturing Practice) certification. For the API (Active Pharmaceutical Ingredient), you must request the Certificate of Analysis (COA) to verify purity levels, typically requiring 98% to 102% on an anhydrous basis. Additionally, check for CEP (Certificate of Suitability) or US DMF (Drug Master File) registration numbers, which indicate the manufacturer meets stringent international pharmacopoeia standards like USP (United States Pharmacopeia) or EP (European Pharmacopoeia).