FDA Warning Letter Trends

Recent FDA warning letters to topical OTC manufacturers continue to highlight familiar GMP deficiencies, with supplier oversight and analytical testing emerging as recurring areas of focus.

In an August warning letter, the FDA emphasized that companies remain responsible for product quality even when manufacturing, packaging, or other activities are outsourced. Effective qualification and ongoing oversight of suppliers and contract facilities remain essential. Analytical testing was also a significant focus. The FDA cited deficiencies in testing programs and emphasized that firms relying on supplier Certificates of Analysis (CoAs) must establish and document the reliability of those results. In another warning letter, the FDA further highlighted the need for component-specific acceptance criteria and scientifically sound, appropriately validated analytical methods. A September letter similarly identified testing programs that were inadequate for their intended purpose. A late-July warning letter to a Germany-based manufacturer also noted that failure to correct violations could result in refusal of entry for products manufactured at the facility, including cosmetics – a point of particular interest for companies operating across both drug and cosmetic product lines.

Other recurring observations included:

Inadequate microbiological control programs

Non-compendial or unvalidated analytical methods

Deficiencies in raw material testing

Inadequate cleaning validation

Insufficient stability studies

These warning letters reinforce the FDA’s continued focus on effective supplier oversight, scientifically justified testing programs, and robust supporting quality systems. Companies should evaluate whether their supplier qualification, COA reliance, analytical methods, microbiological controls, cleaning validation, and stability programs are adequately documented and implemented. Should you require assistance with becoming inspection ready, reach out to us.