Pharmacokinetics of [4-14C] Mofebutazone after oral administration in man

  • M. A. Kassem
  • K. E. Schulte
Original Papers


The pharmacokinetics of mofebutazone was investigated in man after oral administration of [4-14C] mofebutazone in suspension form (7 mg/kg body weight). The blood concentration / time course was found to fit a two compartment open model with first order absorption (ka=10.1 h−1) where elimination (kel=0.304 h−1) occurs only from compartment 1. The maximum concentration was reached after 0.3 h in compartment 1 and after 2 h in compartment 2. Mofebutazone was found to be excreted almost exclusively via the kidney; 97% of the administered dose was found in urine already at 72 h. Excretion takes place very rapidly; 24% of the dose was excreted in 1.5 h and 45% in 3 h. 92% of the mofebutazone excreted was the conjugated form. Two glucuronides were detected in the 24 h urine; one of these seemed to be identical to a glucuronide fractionated from the urine of rat. The renal clearance of mofebutazone in man was found to be 3.38 1/h. The almost complete recovery of mofebutazone in the urine indicates that after oral administration, this drug has a very high bioavailability via the oral route.

Key words

mofebutazone pharmacokinetics oral administration man 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Krohs W. (1965): Pyrazole Derivatives in ‘Analgetics’, edited by G. deStevens, Academic Press, New York, pp. 331–403.Google Scholar
  2. 2.
    Larsen V., Dredahl E. (1966): The embryotoxic effect on rabbits of monophenyl butazone (Monazan) compared with phenylbutazone and thalidomide. Acta Pharmacol. Toxicol.,24, 443–455.Google Scholar
  3. 3.
    Thune S. (1967): Comparison of phenyl- and monophenylbutazone (Mobutazon), especially in respect to the incidence of side effects. A double blind study. Acta Rheumatolog. Scand.,13, 63–80.Google Scholar
  4. 4.
    Woodbury J.F.L., Turner W.A., Tiongson R. (1969): Rheumatoid arthritis: comparison of treatment with monophenylbutazone and phenylbutazone. Can. Med. Assoc. J.101, 801–803.Google Scholar
  5. 5.
    Scarselli V. (1959): Tossicita e cinetica dell eliminazione del 2-fenil, 3,5-diossi, 4-n-butil, pirazolidina comparativamente a quelle del 1,2-difenil-derivato. II Farmaco, Ed. Sci.,14, 347–351.Google Scholar
  6. 6.
    Holmen-Christensen H. (1967): Identification and UV spectrophotometric determination of phenylbutazone analogues from thinlayer chromatograms, in ‘Scientiae Pharmaceuticae’ Vol. II (Proceedings of the 25th Congress of Pharmaceutical Sciences, Prague, 1965), edited by O. Hanc and J. Hubik. Butterworths, London, pp. 152–160.Google Scholar
  7. 7.
    Bass V.-M., Mrongovius R.I. and Schulte K.E. (1980): Disposition of 4-14C mofebutazone in the rat. Eur. J. Drug Metabol. Pharmacok.5, 201–206.CrossRefGoogle Scholar
  8. 8.
    Mrongovius, R., Bass V.-M., and Schulte K.E. (1982): Anti-inflamtory activity and disposition in the rat of mofebutazone and two degradation products. Eur. J. Med. Chem.17, 275–279.Google Scholar
  9. 9.
    Miller J.P. (1971): Health Hazards of Radioactive Pharmaceuticals, in International Encyclopedia of Pharmacology and Therapeutics, Ed.: Peters G., Section 78, Radionucleotides in Pharmacology, Section Ed.: Y. Cohen, Vol. II, pp. 883–901.Google Scholar
  10. 10.
    Wagner J.G. (1975): Fundamentals of Clinical Pharmacokinetics, pp. 102–106, the Hamilton Press, Inc., Hamilton, Illinois.Google Scholar
  11. 11.
    Dieterle W., Faigle J.W., Früh F., Mory H., Theobald W., Alt K.O., and W. Richter (1976): Metabolism of phenylbutazone in man. Arzneim.-Forsch.26, 572–577.Google Scholar
  12. 12.
    Leber H.W., Härders A., and Schütterle G. (1972): Untersuchungen zum Einfluss der Urämie auf die Metabolisierung von Phenylbutazon und Aminophenazon beim Menschen. Klin. Wschr.50, 1092–1096.CrossRefPubMedGoogle Scholar
  13. 13.
    Rowland M., and Riegelman S. (1968): Pharmacokinetics of acetylsalicylic acid after intraveneous administration to rats. J. Pharm. Sci.57, 1313–1319.CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 1984

Authors and Affiliations

  • M. A. Kassem
    • 1
  • K. E. Schulte
    • 2
  1. 1.National Research CentrePharmaceutical Sciences DepartmentCairoEgypt
  2. 2.Institut für Pharmazeutische Chemie der Universität MünsterMünsterF.R.G.

Personalised recommendations