Ethionamide (INN)
Ethionamide (INN) is listed in Annex II as a prohibited substance for cosmetic products placed on the EU market.
Chemical identity and properties
Ethionamide
Ethionamide is a thiocarboxamide that is pyridine-4-carbothioamide substituted by an ethyl group at position 2. A prodrug that undergoes metabolic activation by conversion to the corresponding S-oxide. It has a role as an antitubercular agent, an antilipemic drug, a leprostatic drug, a fatty acid synthesis inhibitor and a prodrug. It is a member of pyridines and a thiocarboxamide. — ChEBI
- IUPAC name
- 2-ethylpyridine-4-carbothioamide
- Molecular formula
- C8H10N2S
- Molecular weight
- 166.25 g/mol
- Exact mass
- 166.05646950 Da
- XLogP3
- 1.1
- Topological polar surface area
- 71.0 Ų
- Hydrogen-bond donors
- 1
- Hydrogen-bond acceptors
- 2
- Covalent units
- 1
- Defined stereocentres
- 0
Also known as
16 more reported names
External database identifiers
- ChEBI:CHEBI:4885
- ChEMBL:CHEMBL1441
- EPA DTXSID:DTXSID0020577
- PubMed:33814510
- PubMed:32808185
- PubMed:26708503
- PubMed:26062974
- PubMed:25051504
- PubMed:23112434
- PubMed:23107633
- PubMed:23106273
- PubMed:23020577
- PubMed:23019444
- PubMed:22952439
- PubMed:22904807
Retrieved from NIH PubChem on 2026-08-31 by checksum-valid CAS matching. Chemical properties do not replace the regulatory decision on this page.
Record details
Chemical name
Ethionamide (INN)
Chemical / IUPAC name
4-Pyridinecarbothioamide, 2-ethyl-; Isonicotinimidic acid, 2-ethylthio-
Regulatory information
Key data
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What Annex II means for Ethionamide (INN)
Ethionamide (INN) is listed as a prohibited substance under Annex II of EU Cosmetics Regulation 1223/2009 and must not be intentionally added. Article 17 separately addresses unintended small quantities that are technically unavoidable under good manufacturing practice and compatible with the Article 3 safety requirement.
Formulators must screen their ingredients and raw materials to ensure none contain this substance. Suppliers should provide documentation confirming absence when requested.
The page also surfaces 12 related annex records with overlapping identifiers, annex logic or naming patterns.
Compliance checklist
- Verify this substance is absent from all raw materials and finished formulations.
- Request absence confirmation or CoA from raw material suppliers.
- Document the screening result in the Product Information File (PIF).
Frequently asked questions
Source note for Annex II record Ethionamide (INN)
This page summarizes one Annex II record for Ethionamide (INN) from public European Commission cosmetic materials and adds linked inventory or identifier matches when available.
Use this record page to review Annex II conditions for Ethionamide (INN), but confirm any final regulatory decision against the current official annex wording and source files.
Tools & next steps
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