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Warning Letter 320-26-04

October 10, 2025

Dear Mr. Liang:

Your facility is registered with the United States Food and Drug Administration (FDA) as a manufacturer of over-the-counter (OTC) drug products. FDA has reviewed the records you submitted in response to our February 10, 2025, request for records and other information pursuant to section 704(a)(4) of the Federal Food, Drug, and Cosmetic Act (FD&C Act) for your facility, Foshan Yiying Hygiene Products Co., Ltd, FEI 3017706051, at Industrial Building No. 3, Ruichang Industrial Park, No. 1, Honggang Section, Lishui Town, Nanhai District, Foshan, Guangdong, China.

This warning letter summarizes significant violations of Current Good Manufacturing Practice (CGMP) regulations for finished pharmaceuticals. See Title 21 Code of Federal Regulations, parts 210 and 211 (21 CFR, parts 210 and 211).

Because your methods, facilities, or controls for manufacturing, processing, packing, or holding of drugs as described in your response to our 704(a)(4) request do not conform to CGMP, your drug products are adulterated within the meaning of section 501(a)(2)(B) of the Federal Food, Drug, and Cosmetic Act (FD&C Act) (21 U.S.C. 351(a)(2)(B)).

Following review of records and other information provided pursuant to section 704(a)(4) of the FD&C Act, significant violations were observed including, but not limited to, the following:

1. Your firm failed to have, for each batch of drug product, appropriate laboratory determination of satisfactory conformance to final specifications for the drug product, including the identity and strength of each active ingredient, prior to release (21 CFR 211.165(a)).

Your firm manufactures OTC drug products, including (b)(4). Your response to our request for records and other information under section 704(a)(4) indicated that you did not conduct adequate finished product testing on drug products shipped to the United States market.

Testing is an essential part of CGMP to ensure that the drug products you manufacture conform to all pre-determined quality attributes appropriate for their intended use. Drug products must be tested for identity and strength of the active ingredient, prior to release and distribution. Without adequate testing, you do not have adequate scientific evidence to assure that your drug products conform to appropriate specifications before release.

2. Your firm failed to assure that the drug product bore an expiration date that was supported by appropriate stability testing (21 CFR 211.137(a)).

Your response to our request for records and other information under section 704(a)(4) indicated that you did not perform stability testing. Therefore, you have not demonstrated that the active ingredient in your drug products is stable throughout its shelf life.

Without appropriate stability data, you cannot ensure your drug products meet established specifications and all pre-determined quality criteria throughout their assigned shelf-life.

3. Your firm failed to conduct at least one test to verify the identity of each component of a drug product. Your firm also failed to validate and establish the reliability of your component supplier’s test analyses at appropriate intervals (21 CFR 211.84(d)(1) and 211.84(d)(2)).

Your response to our request for records and other information under section 704(a)(4) indicated that you did not adequately test the identity of incoming components used in the manufacture of your drug products. You also did not demonstrate that you are testing your active ingredient (b)(4) for (b)(4).

Without adequate testing you do not have scientific evidence that your raw materials conform to appropriate specifications prior to use in the manufacture of your drug products. As a manufacturer, you have a responsibility to sample, test, and examine drug components before use in production to assure adequate quality, including testing for the presence of (b)(4) in (b)(4).

The use of (b)(4) contaminated with (b)(4) has resulted in various lethal poisoning incidents in humans worldwide. See FDA’s guidance document (b)(4).

4. Your firm failed to establish adequate written procedures for production and process control designed to assure that the drug products you manufacture have the identity, strength, quality, and purity they purport or are represented to possess (21 CFR 211.100(a)).

Your response to our request for records and other information under section 704(a)(4) indicated that you did not ensure that your manufacturing processes are reproducible and controlled to yield a product of uniform character and quality. For example, we requested the manufacturing process validation reports for your drug products. In response, you stated you have not validated the manufacturing process for your drug products. In addition, you distributed your drug products to the U.S. market prior to performing process validations.

Process validation evaluates the soundness of design and state of control of a process throughout its lifecycle. Each significant stage of a manufacturing process must be designed appropriately and assure the quality of raw material inputs, in-process materials, and finished drugs. Process qualification studies include intensive monitoring and testing throughout each significant process stage to characterize intra-batch variation and evaluate batches to determine whether an initial state of control has been established.

Successful process qualification studies are necessary before commercial distribution. Thereafter, ongoing vigilant oversight of process performance and product quality is necessary to ensure you maintain a stable manufacturing operation throughout the product lifecycle.

We also note that your quality unit did not ensure that your manufacturing processes were adequately validated and in a state of control before releasing your OTC products for distribution to the U.S. market.

5. Your firm failed to prepare batch production and control records with complete information relating to the production and control of each batch of drug product produced (21 CFR 211.188).

Your response to our request for records and other information under section 704(a)(4) indicated that you did not document all important steps in your manufacturing process. For example, in your response, you stated “…this site does not prepare batch production records for every batch of our listed drug…”. This documentation is necessary to establish that manufacturing processes were consistently followed and are reproducible. Lack of complete records also deprives you of traceability of actions necessary for investigational purposes of any quality signals related to your products.

CGMP Consultant Recommended

Based upon the nature of the violations we identified at your firm, you should engage a consultant qualified as set forth in 21 CFR 211.34 to evaluate your operations and to assist your firm in meeting CGMP requirements. The qualified consultant should also perform a comprehensive six-system audit¹ of your entire operation for CGMP compliance and evaluate the completion and efficacy of your corrective actions and preventive actions before you pursue resolution of your firm’s compliance status with FDA.

Conclusion

The violations cited in this letter are not intended to be an all-inclusive list of violations that exist at your facility. You are responsible for investigating and determining the causes of any violations and for preventing their recurrence or the occurrence of other violations.

FDA placed all drugs and drug products offered for import into the United States from your firm on Import Alert 66-40 on August 27, 2025.

Correct any violations promptly. FDA may withhold approval of new applications or supplements listing your firm as a drug manufacturer until any violations are completely addressed and we confirm your compliance with CGMP. We may inspect to verify that you have completed corrective actions to any violations.

Failure to address any violations may also result in the FDA continuing to refuse admission of articles manufactured at Foshan Yiying Hygiene Products Co., Ltd., Industrial Building No. 3, Ruichang Industrial Park, No. 1, Honggang Section, Lishui Town, Nanhai District, Foshan, Guangdong, China, into the United States under section 801(a)(3) of the FD&C Act, 21 U.S.C. 381(a)(3). Articles under this authority that appear to be adulterated may be detained or refused admission, in that the methods and controls used in their manufacture do not appear to conform to CGMP within the meaning of section 501(a)(2)(B) of the FD&C Act, 21 U.S.C. 351(a)(2)(B).

This letter notifies you of our findings and provides you an opportunity to address the above deficiencies. After you receive this letter, respond to this office in writing within 15 working days. Specify what you have done to address any violations and to prevent their recurrence. In response to this letter, you may provide additional information for our consideration as we continue to assess your activities and practices. If you cannot complete corrective actions within 15 working days, state your reasons for delay and your schedule for completion.

Send your electronic reply to CDER-OC-OMQ-Communications@fda.hhs.gov. Identify your response with FEI 3017706051 and ATTN: Carlos Gonzalez.

Sincerely,
/S/

Francis Godwin
Director
Office of Manufacturing Quality
Office of Compliance
Center for Drug Evaluation and Research

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1 i.e. Quality System, Facilities & Equipment System, Materials System, Production System, Packaging & Labeling System, and Laboratory Control System per FDA’s guidance document Quality Systems Approach to Pharmaceutical CGMP Regulations.