HealthPartners Neuroscience Center Receives FDA Warning Letter Over GLP Mixture Uniformity Failures

Upstream data integrity failures at a nonclinical testing facility have drawn a formal FDA Warning Letter, a signal that regulatory affairs teams supporting IND submissions should weigh carefully when auditing GLP study oversight. HealthPartners Neuroscience Center Research and Innovation (HPNC), Saint Paul, MN, received the letter on May 19, 2026, following an inspection conducted between March 17 and 21, 2025, under FDA's Bioresearch Monitoring Program.

The core citation involves 21 CFR 58.31(d) and 21 CFR 58.113(a)(1): testing facility management failed to verify, by appropriate analytical methods, the uniformity and concentration of test article mixtures before dosing animals across two nonclinical studies. In both protocols, the investigational drug was reconstituted in sterile water at target dose concentrations of 1%, 10%, and 20%, yet no confirmatory analysis was performed on the resulting mixtures prior to administration. The omission means dose-response data submitted in support of the IND cannot be confirmed against a verified concentration baseline.

HPNC acknowledged the deficiency in its April 11, 2025 written response to the Form FDA 483 and in subsequent correspondence dated June 13, 2025. Stated corrective and preventive actions included creation of a new SOP covering receipt, identification, storage, handling, mixing, and analytical method requirements for test articles. FDA's review of the Establishment Inspection Report and both written responses concluded that the facility did not adhere to applicable requirements under the Federal Food, Drug, and Cosmetic Act and 21 CFR Part 58.

For QA directors and regulatory affairs leads overseeing nonclinical programs, the citation reinforces a recurring inspection theme: mixture preparation records and pre-dose analytical verification are not discretionary steps. Facilities acting as testing sites for sponsor-investigators carry the same GLP obligations as contract research organizations operating under formal study agreements, and gaps at this stage can compromise the integrity of data packages submitted to CDER.

The sponsor-investigator named in the studies and the investigational compound are redacted in the public version of the letter; the full inspection record remains with CDER. Regulatory teams should treat the CAPER documentation trail, including SOP version control and analytical method qualification records, as primary inspection-readiness checkpoints ahead of any follow-up CDER review of the affected IND.

Source: FDA Center for Drug Evaluation and Research via FDA.gov Warning Letters database, June 2, 2026. Inspection reference 26-HFD-45-05-02; inspection dates March 17–21, 2025.