Kellin Chemicals Gains Adulteration Designation After Refusing FDA Facility Inspection in Zhangjiagang

Any U.S. finished-drug manufacturer sourcing API from Kellin Chemicals (Zhangjiagang) Co., Ltd. now faces a direct compliance exposure: the firm's refusal of a preannounced FDA inspection has triggered an adulteration designation under section 501(j) of the FD&C Act (21 U.S.C. 351(j)), placing all articles manufactured at its Yangzijiang Chemical Industrial Park site at risk of detention or refused admission at U.S. ports of entry.

FDA's Center for Drug Evaluation and Research (CDER) notified the site of a planned inspection scheduled for July 7–11, 2025. Kellin's U.S. agent, Registrar Corp., confirmed to the agency that the firm refused entry. The resulting Warning Letter, issued November 6, 2025 under FEI 3017343300, formally designates Kellin's drug products, including undisclosed API, as adulterated by virtue of the refusal alone, without any finding of a specific manufacturing defect.

For QA directors and regulatory affairs leads at downstream manufacturers, the statutory exposure is immediate. Receipt of adulterated API and its use as a drug component constitutes a violation of section 301(c) of the FD&C Act (21 U.S.C. 331(c)), independent of whether the finished-drug manufacturer had prior knowledge of the refusal. FDA explicitly recommends that Kellin notify its U.S. customers, a signal that the agency expects downstream firms to act on that notification.

The supply-chain read is direct: any new drug applications or supplements listing Kellin as a manufacturer are subject to approval withholding until FDA completes a satisfactory inspection and confirms CGMP compliance. Firms currently listing the site in an approved application should assess whether a CMC supplement or alternative supplier qualification is required to maintain continuity of supply and regulatory standing.

Kellin has 15 working days from receipt of the letter to respond in writing to CDER, with the option to submit a request to schedule an FDA inspection; until that inspection occurs and compliance is confirmed, the import detention authority under section 801(a)(3) of the FD&C Act remains operative, and the adulteration status stands.

Source: FDA CDER via What's New: Drugs RSS Feed, September 29, 2026 (Warning Letter dated November 6, 2025).