FDA Warning Letter Highlights OOS Handling and Stability Failures

End of September 2025, the United States Food and Drug Administration (FDA) published a new Warning Letter dated 23 September 2025. During an inspection conducted earlier this year at an over-the-counter (OTC) drug manufacturer in Glendale, California, FDA identified multiple significant cGMP violations.

Analytical Data Integrity Issues

The firm’s quality system did not adequately ensure the accuracy and integrity of analytical data:

• Multiple out-of-specification (OOS) results were disregarded without adequate investigation.
• Analytical software access was uncontrolled: shared logins, only “System Administrator” as a user role, and no audit trail review.
• No formal data integrity procedures were implemented.

Stability and OOS Investigations

The FDA noted that three OTC drug products "failed to meet pre-defined quality attributes at multiple timepoints during long-term room temperature storage conditions. A timely and thorough investigation into the root causes of the OOS events was not performed." Specifically:

• Stability Failures: Long-term studies revealed repeated pH and assay failures.
• OOS Handling: Investigations were prematurely closed at Phase I without escalation to Phase II, despite documented trends.

Process Validation & Stability Program Deficiencies

According to the FDA, "changes to the formulations of OTC drug products [...]  were made without demonstrating you have a reproducible commercial manufacturing process, or documented evidence that the reformulated drug products will consistently meet their quality attributes throughout shelf-life."

• Significant formulation changes were introduced without process validation or stability data.
• Process changes were made through handwritten annotations in batch records without justification.
• Stability programs were discontinued despite ongoing failures.

Quality Unit Oversight

The inspection also revealed that the Quality Unit (QU) did not exercise adequate authority. A sunscreen batch initially designated for destruction was reworked without an approved protocol, contemporaneous documentation, or QA approval.

Unapproved Drug Products

Beyond the cGMP violations, FDA determined that two products were marketed as unapproved new drugs under the FD&C Act, as no FDA-approved applications exist for their intended use in treating hyperhidrosis.

Conclusion

FDA requires the company to submit a comprehensive corrective and preventive action (CAPA) plan, supported by an independent consultant. Failure to adequately remediate may result in further enforcement actions, including recalls, import alerts, or withholding of approvals.

For further details, please refer to the complete Warning Letter to Person & Covey, Inc. available on the FDA’s website.