The US Food and Drug Administration has sent a warning letter to a drug maker that used AI agents to create documents for its drug manufacturing. The letter is Warning Letter 320-26-58, dated April 2, 2026. It comes from the FDA's Center for Drug Evaluation and Research. It follows an inspection of the firm's facility from October 28 to 30, 2025.
The letter summarizes significant violations of the federal rules on Current Good Manufacturing Practice for finished pharmaceuticals, which it calls CGMP. Its other findings include insanitary conditions and products released without microbiological testing. One passage stands under the words "Inappropriate Use of Artificial Intelligence in Pharmaceutical Manufacturing." Parts of the letter follow, not the whole.
What the Firm Told the Inspectors
During the inspection, the firm told FDA investigators that it used AI agents to help it comply with FDA regulations. The firm used AI to create its drug product specifications and its procedures. It also used AI to create its master production or control records.
What the Letter Says About AI
The letter tells the firm that if it uses AI as an aid in creating documents, it must review the documents the AI generates. The review is to make sure they are accurate and "actually compliant" with CGMP. The letter says the firm's failure to do so is a violation of 21 CFR 211.22(c).
It also says overreliance on artificial intelligence for the firm's drug manufacturing operations was documented during the inspection. Its example is process validation. FDA investigators found that the firm had not done it before distributing its drug products, as 21 CFR 211.100 requires. They told the firm so. The firm replied that it was not aware of the legal requirement. The AI agent it used, the firm said, never told it the step was required.
A tool that stays silent about a rule does not take the rule away. The letter sets the missing step down as the firm's.
The letter recognizes that the firm has ceased drug production. If the firm plans to resume drug production and use AI to help with CGMP activities, the letter says, any output or recommendations from an AI agent must be "reviewed and cleared." The one who clears it must be an authorized human representative of the firm's quality unit. The letter gives the development of procedures and specifications as examples of such activities. It says this is in accordance with section 501(a)(2)(B) of the Federal Food, Drug, and Cosmetic Act.
The letter does not ban the tool. It names who must clear what the tool produces: an authorized person in the quality unit.
Drug Production Ceased
The firm indicated that it is no longer manufacturing products at the facility. Even so, the letter says, there are still products within expiry in US distribution. Data is required, it says, to support whether the firm's components and drug products meet established specifications. The data must also support that those products will remain within acceptable limits and retain their quality attributes through their labeled shelf life until expiry.
The letter also asks the firm for a commitment. If it intends to resume manufacturing drugs at this facility or any other facility in the future, it will notify the FDA office first.
The Letter's Conclusion
The letter says the violations it cites are not intended to be an all-inclusive list. It says the firm is responsible for investigating and determining the causes of any violations. The firm is also responsible for preventing their recurrence, or the occurrence of other violations. It was told to respond in writing "within 15 working days."
Failure to promptly and adequately address the matter, the letter warns, may result in regulatory or legal action without further notice. The action it names includes, without limitation, seizure and injunction.
Sources
- U.S. Food and Drug Administration, Center for Drug Evaluation and Research (CDER). Warning Letter 320-26-58 (MARCS-CMS 722591), to a drug manufacturer. 2 April 2026. regulator