CGMP/Active Pharmaceutical Ingredient (API)/Adulterated: FDA Warning Letter to Hangzhou Yiqi Biotechnology Co., Ltd, 2026-04-15
Letter issued · posted to fda.gov .
Subject as published: CGMP/Active Pharmaceutical Ingredient (API)/Adulterated
TL;DR
Here's the summary: FDA issued a Warning Letter to Hangzhou Yiqi Biotechnology Co., Ltd on 2026-04-15 citing: CGMP/Active Pharmaceutical Ingredient (API)/Adulterated. Full letter: https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/warning-letters/hangzhou-yiqi-biotechnology-co-ltd-720707-04152026
Argus analysis
Hangzhou Yiqi Biotechnology Co., Ltd (MARCS-CMS 720707, FEI 3035145155) received an FDA Warning Letter dated April 15, 2026 from the Center for Drug Evaluation and Research (CDER). The letter cites: CGMP/Active Pharmaceutical Ingredient (API)/Adulterated. FDA posts Warning Letters to fda.gov after an internal review period; this one was made public on May 19, 2026.
CGMP citations typically reference 21 CFR Part 211 (finished pharmaceuticals) or Part 111 (dietary supplements), covering subjects such as identity testing of incoming components, validated cleaning procedures, batch-failure investigations, and stability program design. Repeat or systemic findings are what typically drive FDA toward import alert or consent decree escalation.
FDA Warning Letters typically specify a 15-working-day response window for the recipient to detail corrective actions. Compliance teams at peer companies in the same CGMP (Current Good Manufacturing Practice) category commonly use a newly published letter as a prompt to re-check their own procedures against the same citation, and to watch fda.gov for a close-out letter confirming the cited firm's corrective action was accepted — or, absent one, for escalation to import alert, injunction, or product seizure.
Severity context
Critical severity. Typically reserved for data integrity, sterile-product CGMP, or repeat violations — matters that historically precede injunctions, consent decrees, or import alerts.
Regulatory background
CGMP citations typically reference 21 CFR Part 211 (drugs) or 21 CFR Part 600 (biologics). Common subjects include identity testing of incoming components (211.84), validated cleaning procedures (211.67), and stability program design (211.166).
What peer compliance teams typically do next
Most compliance officers at peer companies use a Warning Letter against a named entity as a checklist for their own CAPA program. Common steps: pull the verbatim FDA letter; map each cited 21 CFR section against the team’s SOP library; confirm CAPA coverage; brief the QMR (Quality Management Review) on whether the cited subject matter is in scope for the next internal audit. The 15-business-day response window applies to the cited entity, not to peers — but a documented internal review against the cited subjects is what regulators expect to see if a peer is later inspected on the same topic.
Excerpt from the FDA Warning Letter (public domain, 17 USC §105)
WARNING LETTER Hangzhou Yiqi Biotechnology Co., Ltd MARCS-CMS 720707 — April 15, 2026 More Warning Letters Warning Letters About Warning and Close-Out Letters Delivery Method: VIA EMAIL WITH READ RECEIPT Reference #: 320-26-66 Product: Drugs Recipient: Recipient Name Mr. Jack Chai Recipient Title General Manager Hangzhou Yiqi Biotechnology Co., Ltd Room 204, Building 3, No. 66 Xixiang Road, Puyan Street Hangzhou Shi Zhejiang Sheng , 310018 China Issuing Office: Center for Drug Evaluation and Research (CDER) United States Warning Letter 320-26-66 April 15, 2026 Dear Mr. Chai: Your facility is registered with the United States Food and Drug Administration (FDA) as a manufacturer of active pharmaceutical ingredients (APIs). FDA has reviewed the records you submitted in response to our June 16, 2025, request and subsequent correspondence, 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, Hangzhou Yiqi Biotechnology Co., Ltd, FEI 3035145155, at Room 204, Building 3, No. 66 Xixiang Road, Puyan Street, Hangzhou, Zhejiang 310018, China. This Warning Letter summarizes significant deviations from Current Good Manufacturing Practice (CGMP) for APIs. 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 APIs are adulterated within the meaning of section 501(a)(2)(B) of the 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 deviations were observed including, but not limited to, the following: 1. Failure to demonstrate that your manufacturing process can reproducibly manufacture an API meeting its predetermined quality attributes. Based on the records and information you provided, your firm failed to conduct process validation for the (b)(4) APIs manufactured at your facility. These APIs are for use in further processing to produce sterile drug products and for pharmaceutical compounding operations. Process validation evaluates the soundness of design and state of control of a process throughout its life cycle. 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 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. Without adequate process validation, your firm lacks basic assurance that you can reproducibly deliver products that meet specifications. See FDA’s guidance for industry Process Validation: General Princ…
Excerpt only. The full verbatim Warning Letter is the source of truth — always read the original before regulatory decisions.
The verbatim FDA Warning Letter is the source of truth. Always read the original before acting on any analysis or summary on this page.
Read the full letter on fda.gov ↗Frequently asked questions
- Has Hangzhou Yiqi Biotechnology Co., Ltd had FDA enforcement actions before?
- This is the only FDA Warning Letter Argus HQ has on file for Hangzhou Yiqi Biotechnology Co., Ltd as of 2026-05-19. Argus ingests new FDA enforcement records daily.
- What FDA violations was Hangzhou Yiqi Biotechnology Co., Ltd cited for?
- The FDA Warning Letter to Hangzhou Yiqi Biotechnology Co., Ltd (issuing office: Center for Drug Evaluation and Research (CDER)) cites: CGMP/Active Pharmaceutical Ingredient (API)/Adulterated. Classification: CGMP — Current Good Manufacturing Practice.
- When did FDA issue the warning letter to Hangzhou Yiqi Biotechnology Co., Ltd?
- FDA issued the letter (MARCS-CMS 720707) on 2026-04-15 and posted it publicly on fda.gov on 2026-05-19.
- Is the FDA warning letter to Hangzhou Yiqi Biotechnology Co., Ltd publicly available?
- Yes. The full verbatim letter is published at fda.gov. Argus HQ links directly to the source: https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/warning-letters/hangzhou-yiqi-biotechnology-co-ltd-720707-04152026.
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methodology
The analysis above is produced by Anthropic Claude Haiku 4.5 against the verbatim FDA Warning Letter excerpt and is brand-voice lint-checked before publish. The TL;DR is the same summary that ships in the customer email digest. Severity is auto-classified by Argus from the subject string and letter body using rules documented in lib/ingestion/fda-warning-letters.ts.
Argus HQ is informational only. Summaries and analyses are AI-generated and may contain errors, misclassifications, or omissions. Verify against the FDA source URL above. Argus HQ is not a law firm, accounting firm, or regulatory agency, and provides no legal, accounting, financial, medical, or regulatory advice.
Compiled by Argus HQ Research from FDA primary sources · Reviewed by Andy Gaber, Founder
Cite this record
Reusing this data in reporting or research? Here’s a ready-made citation.
Argus HQ Research (2026). CGMP/Active Pharmaceutical Ingredient (API)/Adulterated: FDA Warning Letter to Hangzhou Yiqi Biotechnology Co., Ltd, 2026-04-15. Digital Empire LLC. Retrieved from https://argushq.ai/fda/warning-letter/fda-wl-hangzhou-yiqi-biotechnology-co-ltd-2026-04-15-cgmp
"CGMP/Active Pharmaceutical Ingredient (API)/Adulterated: FDA Warning Letter to Hangzhou Yiqi Biotechnology Co., Ltd, 2026-04-15." Argus HQ Research, Digital Empire LLC, 2026, argushq.ai/fda/warning-letter/fda-wl-hangzhou-yiqi-biotechnology-co-ltd-2026-04-15-cgmp.
Argus HQ Research. "CGMP/Active Pharmaceutical Ingredient (API)/Adulterated: FDA Warning Letter to Hangzhou Yiqi Biotechnology Co., Ltd, 2026-04-15." Digital Empire LLC. Accessed July 13, 2026. https://argushq.ai/fda/warning-letter/fda-wl-hangzhou-yiqi-biotechnology-co-ltd-2026-04-15-cgmp.
@misc{argushq_argushq_ai_fda_warning_letter_fda_wl_hangzhou_yiqi_biotechnology_co_ltd_2026_04_15_cgmp_2026,
title = {CGMP/Active Pharmaceutical Ingredient (API)/Adulterated: FDA Warning Letter to Hangzhou Yiqi Biotechnology Co., Ltd, 2026-04-15},
author = {{Argus HQ Research}},
year = {2026},
publisher = {Digital Empire LLC},
url = {https://argushq.ai/fda/warning-letter/fda-wl-hangzhou-yiqi-biotechnology-co-ltd-2026-04-15-cgmp},
note = {Accessed: July 13, 2026}
}