FDA Warning Letter to Sato Pharmaceutical Co., Ltd. (2026-05-18) — CGMP/Drugs/Adulterated/OTC
Letter issued · posted to fda.gov .
Subject as published: CGMP/Drugs/Adulterated/OTC
TL;DR
The short version: FDA issued a Warning Letter to Sato Pharmaceutical Co., Ltd. on 2026-05-18 citing: CGMP/Drugs/Adulterated/OTC. Full letter: https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/warning-letters/sato-pharmaceutical-co-ltd-723059-05182026
Argus analysis
Sato Pharmaceutical Co., Ltd. (MARCS-CMS 723059, FEI 3004055563) received an FDA Warning Letter dated May 18, 2026 from the Center for Drug Evaluation and Research (CDER). The letter cites: CGMP/Drugs/Adulterated/OTC. FDA posts Warning Letters to fda.gov after an internal review period; this one was made public on May 26, 2026.
Nonprescription/OTC letters typically cite the relevant OTC monograph under 21 CFR Part 330 (or the newer OTC monograph order process under the CARES Act) alongside 21 USC 352 misbranding provisions. Common findings involve active ingredients, dosing, or labeling claims that fall outside the applicable monograph's permitted conditions.
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 Sato Pharmaceutical Co., Ltd. MARCS-CMS 723059 — May 18, 2026 More Warning Letters Warning Letters About Warning and Close-Out Letters Delivery Method: Via Email Return Receipt Requested Reference #: 320-26-75 Product: Drugs Over-the-Counter Drugs Recipient: Recipient Name Seiichi Sato Recipient Title President and CEO Sato Pharmaceutical Co., Ltd. 1-5-27 Moto-Akasaka Minato-ku Tokyo 107-0051 Japan seiichi@sato-seiyaku.co.jp Issuing Office: Center for Drug Evaluation and Research (CDER) United States Secondary Issuing Offices United States May 18, 2026 WARNING LETTER Dear Mr. Sato: The United States Food and Drug Administration (FDA) inspected your drug manufacturing facility, Sato Pharmaceutical Co., Ltd., FEI 3004055563, located at 1468 Hazama-Machi, Hachioji, Tokyo, Japan, from November 13 to 21, 2025. This warning letter summarizes significant violations of Current Good Manufacturing Practice (CGMP) regulations for finished pharmaceuticals. See Title 21 Code of Federal Regulations (CFR), 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). We reviewed your December 12, 2025, response to our Form FDA 483 in detail and acknowledge receipt of your subsequent correspondence. During our inspection, our investigators observed specific violations including, but not limited to, the following. 1. Your firm failed to establish and follow appropriate written procedures that are designed to prevent microbiological contamination of drug products purporting to be sterile, and that include validation of all aseptic processes (21 CFR 211.113(b)). Your ISO 5 area used for aseptic filling of (b)(4) over-the-counter (OTC) (b)(4) drug products is fundamentally unsuitable for its intended use. The design and capability of your aseptic filling line (b)(4) Line) were not sufficient to establish and maintain a state of control. Between November 2022 and February 2025, your attempts to validate your aseptic filling line resulted in at least six media fill failures. Notably, significant microbiological and foreign particulate contamination has been found in this line. The corrective actions you implemented appear insufficient to correct fundamental factors in aseptic process design that are essential to ensure reproducibility and ongoing contamination prevention. This line is used to manufacture (b)(4) drug products intended for the U.S. market, including (b)(4) and (b)(4) . Your design of the ISO 5 area does not ensure unidirectional airflow protection of the aseptic processing line in the event of (b)(4) interventions. The air intake vents for the Grade A laminar airflow ( (b)(4) RABS) are located (b)(4) the RABS (b)(4) near the (b)(4) level on your (b)(4) Filling Line. When a (b)(4) …
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
- What is the regulatory background for a CGMP — Current Good Manufacturing Practice warning letter?
- 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 is the standard FDA response window for a warning letter?
- FDA warning letters typically require a written response within 15 working days of receipt, outlining the corrective and preventive actions the company will take.
- Has Sato Pharmaceutical Co., Ltd. had FDA enforcement actions before?
- Yes. Argus HQ has recorded 2 total FDA actions tied to Sato Pharmaceutical Co., Ltd.: 1 warning letter, 0 recalls, and 0 approval records.
- What FDA violations was Sato Pharmaceutical Co., Ltd. cited for?
- The FDA Warning Letter to Sato Pharmaceutical Co., Ltd. (issuing office: Center for Drug Evaluation and Research (CDER)) cites: CGMP/Drugs/Adulterated/OTC. Classification: CGMP — Current Good Manufacturing Practice.
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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). FDA Warning Letter to Sato Pharmaceutical Co., Ltd. (2026-05-18) — CGMP/Drugs/Adulterated/OTC. Digital Empire LLC. Retrieved from https://argushq.ai/fda/warning-letter/fda-wl-sato-pharmaceutical-co-ltd-2026-05-18-cgmp
"FDA Warning Letter to Sato Pharmaceutical Co., Ltd. (2026-05-18) — CGMP/Drugs/Adulterated/OTC." Argus HQ Research, Digital Empire LLC, 2026, argushq.ai/fda/warning-letter/fda-wl-sato-pharmaceutical-co-ltd-2026-05-18-cgmp.
Argus HQ Research. "FDA Warning Letter to Sato Pharmaceutical Co., Ltd. (2026-05-18) — CGMP/Drugs/Adulterated/OTC." Digital Empire LLC. Accessed July 13, 2026. https://argushq.ai/fda/warning-letter/fda-wl-sato-pharmaceutical-co-ltd-2026-05-18-cgmp.
@misc{argushq_argushq_ai_fda_warning_letter_fda_wl_sato_pharmaceutical_co_ltd_2026_05_18_cgmp_2026,
title = {FDA Warning Letter to Sato Pharmaceutical Co., Ltd. (2026-05-18) — CGMP/Drugs/Adulterated/OTC},
author = {{Argus HQ Research}},
year = {2026},
publisher = {Digital Empire LLC},
url = {https://argushq.ai/fda/warning-letter/fda-wl-sato-pharmaceutical-co-ltd-2026-05-18-cgmp},
note = {Accessed: July 13, 2026}
}