WarningLetterPharmaceuticals-microbiologicalOOSandInadequateMethodValidation
Feb 19, 2026 - Cosmetics
WarningLetterPharmaceuticals-microbiologicalOOSandInadequateMethodValidation
During an inspection of a manufacturing site of an OTC (Over-The-Counter) product manufacturer, the FDA issued a so-called Warning Letter. Essentially, the following points were criticized:
- lack of investigation of a microbiological deviation (OOS = Out of Specification)
- the cause of contamination with Pseudomonas aeruginosa was not adequately examined
- lack of validation and equivalency testing of the rapid microbiological method used compared to USP methods
- insufficient identity testing, particularly of high-risk substances
- an effective CAPA plan (Corrective And Preventive Action) must be in place
In general, it applies to pharmaceutical companies that a microbiological quality management system, including regular microbiological testing, must be in place. Exceptions are possible if the products are low risk in microbiological terms (e.g., anhydrous products).
The microbiological testing must be carried out according to the procedures published in the pharmacopoeias (Ph.Eur. or USP). Deviations from these methods are possible, but the equivalency of the method used with the pharmacopoeia method must be demonstrated.
BAV Institute comprehensively supports you with microbiological testing of your products (microbial counts, specific germs, preservative challenge tests, germ identification). We also support you in case of any anomalies and conduct on-site hygiene inspections. A phone call is enough!
Source:
https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/warning-letters/absolutely-natural-71935690-12302025