Warning Letter Record: kdc/one Chatsworth, Inc. (2026-09-08) — CGMP/Finished Pharmaceuticals/Adulterated
Letter issued · posted to fda.gov .
Subject as published: CGMP/Finished Pharmaceuticals/Adulterated
TL;DR
Key takeaway: The FDA Center for Drug Evaluation and Research issued a warning letter to kdc/one Chatsworth, Inc. (FEI 1000519695) on September 8, 2026, following an inspection conducted March 31–April 3, 2026, citing significant Current Good Manufacturing Practice (CGMP) violations under 21 CFR parts 210–211. The firm failed to establish adequate finished product specifications and stability testing protocols for over-the-counter drug products, including failure to test for a known carcinogenic degradation product despite awareness of contamination in products recalled in Canada; the firm did not determine whether contaminated batches were distributed in the U.S. or conduct appropriate risk assessments for U.S. consumers.
Argus analysis
# FDA Warning Letter Analysis: kdc/one Chatsworth, Inc.
**Facility and Violations**
The FDA's Center for Drug Evaluation and Research (CDER) issued a warning letter to kdc/one Chatsworth, Inc. (FEI 1000519695) in Chatsworth, California on September 8, 2026, following an inspection conducted March 31–April 3, 2026. The agency identified significant Current Good Manufacturing Practice (CGMP) violations in the manufacture of over-the-counter drug products. The core finding: the company's methods, facilities, and controls do not conform to CGMP requirements, rendering distributed products adulterated under the Federal Food, Drug, and Cosmetic Act.
**Regulatory Citations and Context**
The violations cited 21 CFR parts 210 and 211, the foundational CGMP regulations for finished pharmaceuticals. Specifically, the FDA cited 21 CFR 211.165(a) and 211.166(a)—requirements for laboratory determination of batch conformance to final specifications and establishment of adequate stability testing programs. The inspection revealed the company manufactured OTC products without testing for a known degradation impurity that can form a carcinogen under certain conditions. The company distributed at least one batch containing this active ingredient into interstate commerce without required impurity testing, despite being notified of contamination in products recalled in Canada manufactured using identical formulations.
**Next Steps and Industry Observation Points**
The FDA requested a response addressing testing specifications, impurity testing methods, retain sample testing of all currently distributed batches within expiry, market action plans, laboratory system assessment, and comprehensive stability program remediation with timelines. Peer compliance officers should monitor whether kdc/one submits adequate retain sample testing data, implements third-party laboratory qualification, issues recalls for potentially contaminated batches, and demonstrates retrospective risk assessments for distributed products. The failure to investigate out-of-specification viscosity results and inadequately document stability justifications (21 CFR 211.192) suggests systemic investigation and documentation weaknesses that will require demonstrated corrective action.
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 kdc/one Chatsworth, Inc. MARCS-CMS 733205 — September 08, 2026 More Warning Letters Warning Letters About Warning and Close-Out Letters Delivery Method: VIA ELECTRONIC MAIL READ/DELIVERY RECEIPT Reference #: 320-26-124 Product: Drugs Over-the-Counter Drugs Recipient: Recipient Name Mr. Peter F. Rawson Recipient Title Vice President and General Manager kdc/one Chatsworth, Inc. 20320 Prairie St. Chatsworth , CA 91311-6026 United States prawson@kdc-one.com Issuing Office: Center for Drug Evaluation and Research (CDER) United States September 8, 2026 WARNING LETTER Reference number: 320-26-124 To Mr. Peter F. Rawson: This warning letter advises you of significant violations observed during a U.S. Food and Drug Administration (FDA) inspection of your facility. Promptly address the violations described herein without delay, including ensuring that appropriate resources are allocated to fully address the violations and prevent their recurrence. This is not intended to be an all-inclusive list of the violations that exist at your facility. It is your responsibility to ensure that your firm complies with all requirements of federal law, including FDA regulations. Failure to adequately address violations may result in regulatory action without further notice including, without limitation, seizure and injunction. Violations were observed and documented during an inspection of your drug manufacturing facility, kdc/one Chatsworth, Inc., FDA Establishment Identifier (FEI) 1000519695, at 20320 Prairie St., Chatsworth, CA, from March 31 to April 3, 2026. This inspection was conducted under FDA’s statutory authority and public health responsibilities to protect the public from unsafe, ineffective, and poor quality drugs. 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 April 24, 2026, response to our Form FDA 483 in detail. Violations of the Federal Food, Drug, and Cosmetic Act The following are violations identified during our inspection and review. As a reminder, this is not an all-inclusive list of violations at your facility. 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. Your firm also failed to establish and follow an adequate written stability testing program that included reliable, meaningful, and specific test methods for assessing the stability characteristics of…
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
- When did FDA issue the warning letter to kdc/one Chatsworth, Inc.?
- FDA issued the letter (MARCS-CMS 733205) on 2026-09-08 and posted it publicly on fda.gov on 2026-09-22.
- Is the FDA warning letter to kdc/one Chatsworth, Inc. 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/kdcone-chatsworth-inc-733205-09082026.
- What does a "critical" severity rating mean for this letter?
- Critical severity. Typically reserved for data integrity, sterile-product CGMP, or repeat violations — matters that historically precede injunctions, consent decrees, or import alerts.
- 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).
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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). Warning Letter Record: kdc/one Chatsworth, Inc. (2026-09-08) — CGMP/Finished Pharmaceuticals/Adulterated. Digital Empire Holdings LLC. Retrieved from https://argushq.ai/fda/warning-letter/fda-wl-kdc-one-chatsworth-inc-2026-09-08-cgmp
"Warning Letter Record: kdc/one Chatsworth, Inc. (2026-09-08) — CGMP/Finished Pharmaceuticals/Adulterated." Argus HQ Research, Digital Empire Holdings LLC, 2026, argushq.ai/fda/warning-letter/fda-wl-kdc-one-chatsworth-inc-2026-09-08-cgmp.
Argus HQ Research. "Warning Letter Record: kdc/one Chatsworth, Inc. (2026-09-08) — CGMP/Finished Pharmaceuticals/Adulterated." Digital Empire Holdings LLC. Accessed September 23, 2026. https://argushq.ai/fda/warning-letter/fda-wl-kdc-one-chatsworth-inc-2026-09-08-cgmp.
@misc{argushq_argushq_ai_fda_warning_letter_fda_wl_kdc_one_chatsworth_inc_2026_09_08_cgmp_2026,
title = {Warning Letter Record: kdc/one Chatsworth, Inc. (2026-09-08) — CGMP/Finished Pharmaceuticals/Adulterated},
author = {{Argus HQ Research}},
year = {2026},
publisher = {Digital Empire Holdings LLC},
url = {https://argushq.ai/fda/warning-letter/fda-wl-kdc-one-chatsworth-inc-2026-09-08-cgmp},
note = {Accessed: September 23, 2026}
}