FDA warning letter · Drugs

Zhejiang Tianyu Pharmaceutical Co., Ltd.

Issued · Posted by FDA

FDA published a close-out letter on Mar 11, 2025. The passages below are from the original warning letter.

Selected passages from the FDA letter

Quoted FDA text from the published dataset. These selected excerpts are not the complete letter.

Passage 1

Failure to extend investigations to other batches that may have been associated with a specific failure or deviation.

Passage 2

Failure to establish an impurity profile for identified and unidentified impurities.

Passage 3

Your firm failed to conduct a comprehensive evaluation of the manufacturing process to identify all potential impurities.

Passage 4

Failure to clean equipment at appropriate intervals to prevent build-up and carryover of contaminates and degradants where equipment is assigned to continuous production or campaign production of successive batches of the same intermediates and API.

Passage 5

Your firm failed to complete cleaning validation studies prior to release and distribution of **(b)(4)** batches of **(b)(4)** starting material from 2020 to 2022. You acknowledged your cleaning validation was not completed before the batches were distributed. Although the **(b)(4)** is manufactured on dedicated equipment trains, there was no assurance your cleaning methods were adequate and that no contamination was carried over from batch to batch during production campaigns.

Passage 6

Failure to address deviations may also cause FDA to withhold issuance of Export Certificates. FDA may withhold approval of new applications or supplements listing your firm as a drug manufacturer until any deviations are completely addressed and we confirm your compliance with CGMP. We may re-inspect to verify that you have completed corrective actions to address any deviations.