PHR1139 Supelco


Pharmaceutical Secondary Standard; Certified Reference Material

Synonym: 5,5-Diphenyl-2,4-imidazolidinedione, 5,5-Diphenylhydantoin, Phenytoin

  • CAS Number 57-41-0

  • Empirical Formula (Hill Notation) C15H12N2O2

  • Molecular Weight 252.27

  •  Beilstein/REAXYS Number 384532

  •  EC Number 200-328-6

  •  MDL number MFCD00005264

  •  PubChem Substance ID 329823159

  •  NACRES NA.24



Related Categories Analytical Standards, Analytical/Chromatography, P-S, Pharmaceutical Secondary Standards, Pharmacopeia & Metrological Institutes Standards More...
grade   certified reference material
  pharmaceutical secondary standard
form   neat
mp   293-295 °C (lit.)
Featured Industry   Pharmaceutical (small molecule)
format   neat
pharmacopeia traceability   traceable to PhEur P1290000
  traceable to USP 1535008


General description

Phenytoin is a well-known aromatic anticonvulsant which undergoes metabolism in the hepatic microsomal system. It finds its application as the most effective treatment available for seizure disorders. It belongs to the class of phenyl hydantoins compounds. It can hinder the unnecessary activity of the brain during seizures by bringing stability to the sodium channels, causing decreased electrical conductivity among brain cells.
Pharmaceutical secondary standards for application in quality control, provide pharma laboratories and manufacturers with a convenient and cost-effective alternative to the preparation of in-house working standards.


Phenytoin may be used as a pharmaceutical reference standard in the determination of the analyte in pharmaceutical formulations and combined dosage forms by electrochemical, spectrophotometric, and chromatographic techniques.

These Secondary Standards are qualified as Certified Reference Materials. These are suitable for use in several analytical applications including but not limited to pharma release testing, pharma method development for qualitative and quantitative analyses, food and beverage quality control testing, and other calibration requirements.

Biochem/physiol Actions

Reduces incidence of grand mal seizures; appears to stabilize excitable membranes perhaps through effects on Na+, K+, and Ca2+ channels.

Analysis Note

These secondary standards offer multi-traceability to the USP, EP (PhEur) and BP primary standards, where they are available.

Other Notes

This Certified Reference Material (CRM) is produced and certified in accordance with ISO 17034 and ISO/IEC 17025. All information regarding the use of this CRM can be found on the certificate of analysis.

Values of analytes vary lot to lot.


To see an example of a Certificate of Analysis for this material enter LRAB7779 in the slot below. This is an example certificate only and may not be the lot that you receive.

Safety & Documentation

Safety Information

Signal word 
Hazard statements 
Precautionary statements 
NONH for all modes of transport
WGK Germany 


Certificate of Analysis (COA)

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Protocols & Articles
Peer-Reviewed Papers


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