FDA Warning Letter to Respilon Production S.R.O. (April 20, 2026) — CGMP/OTC/Finished Pharmaceuticals/Adulterated

FDA Warning Letter — Violations FDA cited at Respilon Production S.R.O.

WARNING LETTER Respilon Production S.R.O. MARCS-CMS 719705 — April 20, 2026 More Warning Letters Warning Letters About Warning and Close-Out Letters Delivery Method: Via Email Reference #: 320-26-69 Product: Drugs Over-the-Counter Drugs Recipient: Recipient Name Mr. Roman Zima Recipient Title Chief Executive Officer Respilon Production S.R.O. Prikop 843/4 Brno 602 00 Jihomoravsky Czechia Issuing Office: Center for Drug Evaluation and Research (CDER) United States Warning Letter 320-26-69 April 20, 2026 Dear Mr. Zima: 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 May 2, 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, Respilon Production S.R.O, FEI 3018892481, at Prikop 843/4, Brno, Jihomoravsky, Czech Republic. 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 our review of records and other information you 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 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 under section 704(a)(4) indicated that you do not test the identity of each incoming component used in the manufacture of your drug products, such as (b)(4) , before manufacturing. In addition, you failed to test each shipment of (b)(4) for (b)(4) contamination before use. Identity testing for (b)(4) and certain other high-risk drug components includes a limit test in the United States Pharmacopeia (USP) to ensure that the component meets the relevant safety limits for levels of (b)(4) . Because you did not perform adequate identity testing on each shipment of each lot using the USP identification test that detects these hazardous impurities, you failed to ensure the acceptability of these components for use in the manufacturing of your drug product. See FDA’s guidance document (b)(4) for help in meeting the CGMP requirements when manufacturing drugs containing ingredients at high risk for (b)(4) contamination. 2. Your firm failed to establish and follow an adequate written testing program designed to assess the stability characteristics of drug products (21 CFR 211.166(a)). Your response to our request for records under section 704(a)(4) indicated that you have not performed stability studies for the OTC drug products you manufacture, despite your drug product’s displaying an expiration date on the label. Without the appropriate stability studies, you do not have scientific evidence to support whether your drug product’s active ingredient maintains its strength, purity, and quality throughout the shelf life of the product. 3. 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 under section 704(a)(4) indicated