FDA WARNING_LETTER - Guangdong Renhe Guozhuang Biotechnology Co., Ltd - June 23, 2025

The FDA issued a Warning Letter on December 16, 2025, to Guangdong Renhe Guozhuang Biotechnology Co., Ltd. following a review of records submitted in response to an April 28, 2025 request. The letter identified significant violations of Current Good Manufacturing Practice (CGMP) regulations (21 CFR, parts 210 and 211), rendering the company"s over-the-counter (OTC) drug products adulterated.

The main issues included the firm"s failure to ensure each batch of drug product conformed to final specifications, including identity and strength of active ingredients, and failure to conduct necessary microbiological testing prior to release. The company could not demonstrate adequate testing of its finished OTC drug products, including sterile items. Additionally, the company failed to perform adequate identity testing for each component of its drug products, specifically high-risk incoming components susceptible to (b)(4) contamination, a known cause of lethal poisoning, and did not provide requested data to prove testing.

Required actions include providing a list of specifications and methods for drug product analysis, an action plan to test reserve samples of all distributed batches within expiry, and a comprehensive independent assessment of laboratory practices. For component testing, the firm must provide (b)(4) test results for high-risk components, conduct a full risk assessment for affected drug products, perform an independent review of its material system, and detail plans for future identity testing of incoming materials to ensure quality and safety.