PLASMA-CONCENTRATIONS OF S-VERAPAMIL AFTER SINGLE DOSES OF 2 DIFFERENT GALENIC FORMULATIONS OF RACEMIC VERAPAMIL

The results of enantioselective analysis of verapamil (CAS 52-53-9) in plasma samples obtained at t(max) after single dose applications of a 80 mg fast dissoluting (IR) tablet, a controlled release (CR) formula tion (240 mg) and an intravenous injection of 5 mg verapamil are repor ted The mean fraction of S-verapamil obtained in samples containing th e C(max) of racemic verapamil was somewhat smaller after application o f the IR-form than observed with the CR formulation (IR = 15.8 +/- 3.8 %; CR = 18.8 +/- 2.0%; p < 0.01), after the intravenous application th e mean S-fraction was 32.8 +/- 1.4%. In vitro dissolution tests of the two oral preparations prove that the isomers were released as racemat e.