FDA Cracks Down on Sterile Drug Manufacturing Violations
The U.S. Food and Drug Administration (FDA) has issued a warning letter to Daewoo Pharmaceutical Co., Ltd. in Busan, South Korea, citing serious and widespread violations of current Good Manufacturing Practices (CGMP) for sterile drug production. Following an inspection in January 2025, the agency flagged major deficiencies in aseptic processing, quality control, facility design, and contamination prevention.
Sterility Assurance Failures
FDA investigators found inadequate airflow and aseptic technique in cleanroom areas, poorly executed smoke studies, and media fills that failed to simulate worst-case conditions. Operators were observed with exposed skin in ISO 5 areas, using non-sterile materials, and skipping critical interventions in contamination simulations.
Lapses in Environmental and Personnel Monitoring
Daewoo’s environmental monitoring lacked scientific justification, especially in high-risk ISO 5 and 7 zones. Personnel monitoring practices were found to be inconsistent, and gowning qualification procedures were absent.
Inadequate Visual Inspections and Equipment Cleaning
Inspections found that the company’s visual inspection system for filled drug containers was incomplete and poorly documented, lacking proper training and defect libraries. Cleaning procedures varied widely between operators and failed to account for all material surfaces or equipment types.
Facility and Equipment Design Deficiencies
FDA documented that critical manufacturing lines were poorly designed, with gaps in HEPA filter coverage and reliance on disinfection—not sterilization—of direct product-contact equipment. In addition, equipment was not properly validated or maintained.
Weak Quality Oversight
According to the warning letter, the Quality Unit (QU) failed in its core responsibilities: no written procedures for critical operations, inadequate investigations of microbial contamination trends, and insufficient complaint handling (e.g., skipping sterility tests for contaminated products). Testing of raw materials was lacking, especially for components at high risk of contamination with deadly toxins.
Daewoo Suspends Drug Production
Daewoo has halted all drug manufacturing and deregistered its facility with the FDA. However, the agency has requested clarification on whether the company plans to resume operations. If so, Daewoo must retain an independent CGMP consultant and demonstrate robust corrective actions across its systems.
What’s Next?
Until the FDA verifies that Daewoo has fully remediated its operations, the agency may:
- Withhold new drug application approvals listing Daewoo as a manufacturer
- Detain imports from the facility into the U.S.
- Re-inspect to confirm compliance
This warning underscores the FDA’s zero-tolerance stance on lapses in sterile drug manufacturing, especially when patient safety is at risk.
For manufacturers, it’s a powerful reminder: robust aseptic practices, quality oversight, and validated cleaning protocols are non-negotiable.
Warning letter text
Read the full text of the FDA warning letter to Daewoo Pharmaceutical here.