U.S. flag An official website of the United States government
  1. Home
  2. Inspections, Compliance, Enforcement, and Criminal Investigations
  3. Compliance Actions and Activities
  4. Warning Letters
  5. Ningbo Poplar Daily-Use - 669486 - 02/05/2024
  1. Warning Letters


Ningbo Poplar Daily-Use MARCS-CMS 669486 —

Delivery Method:
Reference #:

Recipient Name
Mr. Gao Lingyan
Ningbo Poplar Daily-Use

Mingguang Road 198, Shounan St
Yinzhou Qu
Ningbo Shi
Zhejiang Sheng, 315100

Issuing Office:
Center for Drug Evaluation and Research | CDER

United States

Secondary Issuing Offices

United States

Warning Letter 320-24-20

February 5, 2024

Dear Mr. Lingyan:

Your facility was registered with the U.S. 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 June 10, 2022, and June 24, 2022 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, Ningbo Poplar Daily-Use, FEI 3019951059, at Mingguang Road 198, Shounan St, Yinzhou, Ningbo.

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 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)).

704(a)(4) Request for Records and Related CGMP Violations

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)).

Based on the records and information you provided, you did not demonstrate that you adequately test your OTC finished drug products prior to release for distribution to the United States. Specifically, the records you provided demonstrate that you failed to perform assay testing and (b)(4) testing on your finished (b)(4) drug products. In lieu of your finished product specifications, you only provided a “Drug Facts Label.” Additionally, the test method you provided uses a hydrometer device that is unsuitable for the testing of finished (b)(4) that contain materials other than (b)(4) and (b)(4) in their matrix. Your drug product also contains (b)(4). The use of this unsuitable device to test your finished (b)(4) products violates CGMP requirements as defined under 21 CFR 211.160(b), requiring the use of scientifically sound and appropriate test procedures to, among other things, assure that drug products conform to appropriate standards of identity, strength, quality, and purity.

Full release testing, including for identity, strength, and impurities, must be performed prior to drug release and distribution. Without adequate testing, there is no scientific evidence to assure that your drug products conform to appropriate specifications before release.

In response to this letter, provide:

  • A list of chemical and microbial specifications, including adequate test methods, used to analyze each batch of your drug products before a batch disposition decision.

    o An action plan and timelines for conducting full chemical and microbiological testing of retain samples to determine the quality of all batches of drug product distributed to the United States that are within expiry as of the date of this letter.
    o A summary of all results obtained from testing retain samples from each batch. If such testing reveals substandard quality drug products, take rapid corrective actions, such as notifying customers and product recalls.

2. Your firm failed to conduct at least one test to verify the identity of each component of a drug product (21 CFR 211.84(d)(1)).

Based on the records and information you provided, you did not demonstrate that you are testing the identity of incoming components used in the manufacture of your drug products. Additionally, you are not testing your incoming lots of (b)(4) for (b)(4), which is used to manufacture the (b)(4) for distribution in the United States.

In your response, you state you perform identity testing on all raw materials before use in manufacturing. However, you only provided your supplier’s test reports.

Component testing is fundamental to quality. Without adequate testing, you do not have scientific evidence that your raw materials conform to appropriate specifications before use in the manufacture of your drug products.

Products Contain (b)(4)

You manufacture drugs that contain (b)(4). The use of (b)(4) contaminated with (b)(4) has resulted in various lethal poisoning incidents in humans worldwide. (b)(4).

In response to this letter, provide:

  • The chemical and microbiological quality control specifications you use to test and release each incoming lot of component for use in manufacturing.
  • A description of how you will test each component lot for conformity with all appropriate specifications for identity, strength, quality, and purity. If you intend to accept any results from your supplier’s Certificates of Analysis (COA) instead of testing each component lot for strength, quality, and purity, specify how you will robustly establish the reliability of your supplier’s results through initial validation as well as periodic re-validation. In addition, include a commitment to always conduct at least one specific identity test for each incoming component lot.
  • A summary of results obtained from testing all components to evaluate the reliability of the COA from each component manufacturer. Include your standard operating procedure (SOP) that describes this COA validation program.
  • A summary of your program for qualifying and overseeing contract facilities that test the drug products you manufacture.

3. Your firm failed to establish and follow an adequate written testing program designed to assess the stability characteristics of drug products and to use results of stability testing to determine appropriate storage conditions and expiration dates (21 CFR 211.166(a)).

Based on the records and information you provided for stability, you did not demonstrate that the chemical properties of your drug products remain acceptable throughout the labeled expiry period of 24 months.

Without appropriate stability studies, you do not have scientific evidence to support whether your drug products meet established specifications and retain their quality attributes through their labeled expiry.

In response to this letter, provide:

  • A comprehensive, independent assessment and corrective action and preventive action (CAPA) plan to ensure the adequacy of your stability program. Your remediated program should include, but not be limited to:

    o Stability indicating methods
    o Stability studies for each drug product in its marketed container-closure system before distribution is permitted
    o An ongoing program in which representative batches of each product are added each year to the program to determine if the shelf-life claim remains valid
    o Detailed definition of the specific attributes to be tested at each station (timepoint)

    All procedures that describe these and other elements of your remediated stability program.

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 assist your firm in meeting CGMP requirements if your firm intends to resume manufacturing drugs for the U.S. market. The qualified consultant should also perform a comprehensive audit 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.

Your use of a consultant does not relieve your firm’s obligation to comply with CGMP. Your firm’s executive management remains responsible for resolving all deficiencies and systemic flaws to ensure ongoing CGMP compliance.


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.

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 refusing admission of articles manufactured at Ningbo Poplar Daily-Use, at Mingguang Road 198, Shounan St, Yinzhou, 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 or misbranded 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) and are misbranded under section 502 of the FD&C Act, respectively.

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 [email protected]. Identify your response with FEI 3009675687 and ATTN: Chhaya Shetty.


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

Back to Top