RELATIVE BIOAVAILABILITY OF 3 DIFFERENT CHLORMEZANONE 200-MG PREPARATIONS AFTER SINGLE-DOSE ORAL-ADMINISTRATION

Eighteen male volunteers have been treated with 3 different oral formu lations of chlormezanone according to a randomized 3-way change-over d esign. The test preparation was a tablet (Krewel), reference preparati on 1 was a suspension (Krewel), and reference preparation 2 was a tabl et (Muskel Trancopal, Sanofi Winthrop GmbH). All preparations containe d 200 mg of chlormezanone. Divided in 3 periods the volunteers receive d single doses of the test and the 3 reference formulations, respectiv ely. Blood samples have been drawn immediately prior to each administr ation 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 revers ed-phase HPLC method with UV detection, with a lower limit of quantifi cation of 0.1 mu g/ml. The following mean values have been obtained fo r the test preparation: AUC(0-infinity) 121 mu g X h/ml, C-max of 2.9 mu g/ml at 1.5 h, t(1/2) 38 h, after administration of the suspension: AUC(0-infinity) 111 mu g X h/ml, C-max 2.6 mu g/ml, t(max) 1.5 h, t(1 /2) 40 h, and after administration of the reference tablet: AUC(0-infi nity) 121 mu g x h/ml, C-max 3.0 mu g/ml, t(max) 1.6 h, t(1/2) 38 h. T he test preparation shows a relative bioavailability of 109% compared to the suspension and has been proven to be bioequivalent to the refer ence tablet with regard to extent and rate of absorption.