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Annex II Entry 67 17/10/2010

Phenylbutazone (INN)

Phenylbutazone (INN) is listed in Annex II as a prohibited substance for cosmetic products placed on the EU market.

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Prohibited substance— Annex II, EU Regulation 1223/2009
Entry: 67

Chemical identity and properties

PubChem 2D chemical structure for CAS 50-33-9
CAS 50-33-9PubChem CID 4781

Phenylbutazone

Phenylbutazone is a member of the class of pyrazolidines that is 1,2-diphenylpyrazolidine-3,5-dione carrying a butyl group at the 4-position. It has a role as a metabolite, a non-steroidal anti-inflammatory drug, a non-narcotic analgesic, an antirheumatic drug, a peripheral nervous system drug and an EC 1.1.1.184 [carbonyl reductase (NADPH)] inhibitor. — ChEBI

IUPAC name
4-butyl-1,2-diphenylpyrazolidine-3,5-dione
Molecular formula
C19H20N2O2
Molecular weight
308.4 g/mol
Exact mass
308.152477885 Da
XLogP3
3.2
Topological polar surface area
40.6 Ų
Hydrogen-bond donors
0
Hydrogen-bond acceptors
2
Covalent units
1
Defined stereocentres
0

Also known as

ButapirazolButadionButazolidinFlexazoneAzolidButacoteButazolidineEcobutazone
16 more reported names
FenibutazonaFenilbutazonaFenylbutazonIntrabutazoneArtrizinButadionaDiphebuzolFenibutolIntrazonePhebuzineButozBuzonDiphenylbutazoneEquipalazonePhenylbutazonumAlkabutazona
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External database identifiers

Retrieved from NIH PubChem on 2026-09-02 by checksum-valid CAS matching. Chemical properties do not replace the regulatory decision on this page.

Record details

Chemical name

Phenylbutazone (INN)

Regulatory information

Regulation

(EC) 2009/1223

See every entry this act set

Key data

CAS
50-33-9
EC
200-029-0
Annex
II
Entry number
67

Direct matches are limited for this record, so nearby entries from Annex II are shown as well.

Annex II 70
Nearby record in the same annex

Cantharidine

CAS: 56-25-7
EC: 200-263-3
Annex II 62
Nearby record in the same annex

Brucine

CAS: 357-57-3
EC: 206-614-7

What Annex II means for Phenylbutazone (INN)

Phenylbutazone (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

Yes. Phenylbutazone (INN) is listed in Annex II of EU Cosmetics Regulation 1223/2009 and is prohibited as an intentionally added cosmetic ingredient. Article 17 provides a narrow exception for unintended small quantities that are technically unavoidable under good manufacturing practice, provided the product remains safe under Article 3.

CAS 50-33-9 is the unique numerical identifier assigned to Phenylbutazone (INN) by the Chemical Abstracts Service. In cosmetic compliance work, the CAS number is used to cross-reference the substance across regulatory databases, raw material specifications and safety assessment reports. Multiple EU annex entries may share the same CAS number if the same substance appears under different conditions or in different annexes.

Use the INCI Checker tool on this site to paste your full ingredient list (INCI) and scan it against all Annex II–VI entries. The tool highlights any ingredients that match restricted, prohibited or allergen-flagged records. This is useful for rapid compliance screening of finished product formulas or raw material declarations.
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Source note for Annex II record Phenylbutazone (INN)

This page summarizes one Annex II record for Phenylbutazone (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 Phenylbutazone (INN), but confirm any final regulatory decision against the current official annex wording and source files.

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