FDA Warning Letter Cites Serious Microbiological and Technical Failures at Liebel-Flarsheim

Following an inspection conducted in March and April 2025, the FDA issued a Warning Letter to Liebel-Flarsheim Company LLC, a U.S. manufacturer of terminally sterilized medicinal products, citing significant GMP violations. Key concerns involved repeated microbiological deviations, improper handling of endotoxin out-of-specification (OOS) results, and major deficiencies in cleanrooms and utilities.

Since 2022, more than 40 in-process bioburden tests exceeded limits, including results described as “too numerous to count” and involving gram-negative bacteria capable of producing endotoxins. FDA investigators found that root-cause investigations were superficial and often inconclusive, with unjustified invalidation of endotoxin OOS results and release of affected batches to the U.S. market.

The inspection also revealed poorly maintained ISO 5 and ISO 7 cleanrooms and a severely degraded steam system with corrosion, leaks, and condensate buildup—conditions conducive to contamination. The FDA rejected the firm’s extended remediation timeline and recommended engaging an external GMP consultant to ensure timely and effective corrective actions.

09-02-2026