Skip to Main Navigation
Skip to Page Content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it's official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you're on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Testing Status of Primidone (primaclone) 10270-A

 

CASRN: 125-33-7

Formula: C12-H14-N2-O2

Synonyms/Common Names

  • 5-Ethyldihydro-5-phenyl-4,6(1H,5H)-pyrimidinedione (9CI)

Short-Term Toxicity

  • 2 weeks (Dosed-Feed)  (C88035)  Completed 
    • Rats: F344/N; Mice: B6C3F1
    • Dose: R: 0, 0.125, 0.25, 0.5, 1.0, OR 2.0% M: 0, 0.0625, 0.125, 0.25, 0.5, OR 1.0% (5/SEX/SPECIES).
  • 13 weeks (Dosed-Feed)  (C88035)  Completed 
    • Rats: F344/N; Mice: B6C3F1
    • Dose: R&M: 0, 0.03, 0.06, 0.13, 0.25, OR 0.5% 20 RATS/SEX + 10 MICE/SEX.

Long-Term Carcinogenicity

  • 2 years (Dosed-Feed)  (C88035)  Completed 
    • TR-476 (NIH Number: 00-3966)  (Peer Review Approval 12/12/1996A )
      Toxicology and Carcinogenesis Studies of Primidone (CASRN 125-33-7) in F344/N Rats and B6C3F1 Mice (Feed Studies)
    • Rats: F344/N; Mice: B6C3F1
    • Carcinogenesis Results
      • Male Rats Equivocal Evidence 
      • Female Rats No Evidence 
      • Male Mice Clear Evidence 
      • Female Mice Clear Evidence 
    • Dose: M: 0, 0.03, 0.06, OR 0.13% R: 0, 0.06, 0.13, OR 0.25% (50/SEX/SPECIES).

Special Studies

  • Toxicokinetic Study  (K88035)  Completed 
    • Rats; Mice
  • Toxicokinetic Study (Gavage)  (S0560)  Completed 
    • Male and Female Rats: F344/N; Male and Female Mice: B6C3F1
    • Dose: 14D: RAT 0.125, 0.25, 0.5, 1.0 OR 2.0%; MICE 0.0625, 0.125, 0.25, 0.5 OR 1.0%; 90D: R&M 0.03, 0.06, 0.13, 0.25 OR 0.5%; 104W: RAT 0.06, 0.13 OR 0.25%; MICE 0.03, 0.06 OR 0.13%.

Genetic Toxicology

  • In Vitro Cytogenetics (CA/SCE)  (945872)  Completed 
    • Sister Chromatid Exchange Negative 
    • Chromosome Aberrations Negative 
  • Micronucleus  (754198)  Completed 
    • Mice: B6C3F1
    • Male Negative 
  • Micronucleus  (A69181)  Completed 
    • Mice: B6C3F1
    • Male Negative 
    • Female Negative 
  • Salmonella  (323716)  Completed 
    • Citation: Mortelmans, K., Haworth, S., Lawlor, T., Speck, W., Tainer, B., and Zeiger, E. Salmonella mutagenicity tests. II. Results from the testing of 270 chemicals Environ. Mutagen. Vol. 8 (Suppl 7) (1986) 1-119
    •  Positive 

Organ Systems Toxicity

  • Continuous Breeding (Legacy) (Dosed-Feed)  (RACB90009)  Completed 
    • Mice: Swiss
    • Dose: 0.03-0.05%; 0, 0.015, 0.05, .15%; N/A; 0, .15%.