National Toxicology Program

CASRN: 50-33-9

Formula: C19-H20-N2-O2

Synonyms/Common Names:

• 4-BUTYL-1,2-DIPHENYL-3,5-PYRAZOLIDINEDIONE (9CI)

Known Uses:

VETERINARY USE AS ANTI-INFLAMMATORY AGENT AND ANALGESIC. (TDB)

Short-Term Toxicity

• 2-WEEK (Gavage)  (C56531) Completed 
  • NTIS No. PB90-258765  (Peer Review 03/13/1989)
    Citation: Toxicology and Carcinogenesis Studies of Phenylbutazone (CAS No. 50-33-9) in F344/N Rats and B6C3F1 Mice (Gavage Studies)
  • Rats: F344/N; Mice: B6C3F1
• 13-WEEK (Gavage)  (C56531) Completed 
  • NTIS No. PB90-258765  (Peer Review 03/13/1989)
    Citation: Toxicology and Carcinogenesis Studies of Phenylbutazone (CAS No. 50-33-9) in F344/N Rats and B6C3F1 Mice (Gavage Studies)
  • Rats: F344/N; Mice: B6C3F1
  • Dose: R: 0, 25, 50, 100, 200, OR 300 MG/KG M: 0, 40, 80, 150, 300, OR 600 MG/KG

Long-Term Carcinogenicity

• 2-YEAR (Gavage)  (C56531) Report Complete 
  • TR-367 (NTIS No. PB90-258765)  (Peer Review 03/13/1989)
    Toxicology and Carcinogenesis Studies of Phenylbutazone (CAS No. 50-33-9) in F344/N Rats and B6C3F1 Mice (Gavage Studies)
  • Rats: F344/N; Mice: B6C3F1
  • Carcinogenesis Results
  • Male Rats Equivocal Evidence 
  • Female Rats Some Evidence 
  • Male Mice Some Evidence 
  • Female Mice No Evidence 
  • Dose: R: 0, 50, 100, M: 0, 150, 300 MG/KG/50 PER GROUP

Genetic Toxicology

• In Vitro Cytogenetics (CA/SCE)  (534081) Completed 
  • Citation: Galloway, S., Armstrong, M., Reuben, C., Colman, S., Brown, B., Cannon, C., Bloom, A., Nakamura, F., Ahmed, M., Duk, S., Rimpo, J., Margolin, B., Resnick, M., Anderson, B., and Zeiger, E. Chromosome aberration and sister chromatid exchanges in Chinese hamster ovary cells: Evaluations of 108 chemicals. Environ. Molec. Mutagen. Vol. 10 (Suppl 10) (1987) 1-176
  • Chromosome Aberation Positive 
  • Sister Chromatid Exchange Negative 
• Mouse Lymphoma  (421302) Completed 
  •  Positive 
• Micronucleus  (476079) Completed 
  • Mice: B6C3F1
  • Male Negative 
• Salmonella  (030078) 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
  •  Negative