CTK OTC Laboratories LLC – FDA 483, May 4, 2026

CTK OTC Laboratories LLC, a contract manufacturer in Corona, CA, was inspected and cited for significant quality control deficiencies. Observations included failures to investigate out-of-specification results and batch yield discrepancies, inadequate cleaning validation and procedures for shared equipment, and a lack of proper qualification and monitoring for critical laboratory equipment. These issues indicate a systemic failure to ensure product quality and prevent contamination.