Relative bioavailability of 3 different chlormezanone 200 mg preparations after single dose oral administration

Int J Clin Pharmacol Ther. 1997 Mar;35(3):112-6.


Eighteen male volunteers have been treated with 3 different oral formulations of chlormezanone according to a randomized 3-way change-over design. The test preparation was a tablet (Krewel), reference preparation 1 was a suspension (Krewel), and reference preparation 2 was a tablet (Muskel Trancopal, Sanofi Winthrop GmbH). All preparations contained 200 mg of chlormezanone. Divided in 3 periods the volunteers received single doses of the test and the 2 reference formulations, respectively. Blood samples have been drawn immediately prior to each administration and at 21 sampling points within 144 h after dosing. A wash-out period of 2 weeks was maintained between successive drug doses. Plasma concentrations of chlormezanone were determined by a validated reversed-phase HPLC method with UV detection, with a lower limit of quantification of 0.1 microgram/ml. The following mean values have been obtained for the test preparation: AUC0-infinity 121 micrograms x h/ml, Cmax of 2.9 micrograms/ml at 1.5 h, t1/2 38 h, after administration of the suspension: AUC0-infinity 111 micrograms x h/ml, Cmax 2.6 micrograms/ml, tmax 1.5 h, t1/2 40 h, and after administration of the reference tablet: AUC0-infinity 121 micrograms x h/ml, Cmax 3.0 micrograms/ml, tmax 1.6 h, t1/2 38 h. The test preparation shows a relative bioavailability of 109% compared to the suspension and has been proven to be bioequivalent to the reference tablet with regard to extent and rate of absorption.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Administration, Oral
  • Adolescent
  • Adult
  • Analysis of Variance
  • Biological Availability
  • Chlormezanone / administration & dosage
  • Chlormezanone / blood
  • Chlormezanone / pharmacokinetics*
  • Chromatography, High Pressure Liquid
  • Cross-Over Studies
  • Humans
  • Male
  • Muscle Relaxants, Central / administration & dosage
  • Muscle Relaxants, Central / blood
  • Muscle Relaxants, Central / pharmacokinetics*
  • Reference Standards
  • Regression Analysis
  • Spectrophotometry, Ultraviolet
  • Therapeutic Equivalency


  • Muscle Relaxants, Central
  • Chlormezanone