MD Pharmaceutical Supply, LLC, a drug repackaging and relabeling facility, failed to comply with current good manufacturing practices (CGMP) for active pharmaceutical ingredients (APIs), rendering their APIs adulterated. During an April-May 2022 inspection, the FDA identified critical deficiencies including failure to adequately investigate customer complaints and quality issues before redistributing returned API lots, and discrepancies in certificates of analysis (COAs) where the company distributed APIs using COAs with incorrect expiration dates that differed from documentation provided by the original manufacturer. Specifically, the company redistributed a phentolamine mesylate API lot that had been returned for quality issues without proper investigation, and later distributed aminocaproic acid API using a COA with an April 2024 expiration date when the actual COA showed April 2023.