Bioavailability of three oral dosage forms of cisapride, a gastrointestinal stimulant agent

Relative bioavailability of the investigational gastrointestinal stimulant agent cisapride after oral administraion was determined in healthy men. Treatments administered were (A) two-5-mg tablets; (B) one 10-mg tablet; (C) 10 mL of a l-mg/mL suspension; and (D) 10 mL of a 1-mg/mL aqueous reference solution. The study had a randomized four-way crossover design; drug administration was followed by a standard breakfast. Plasma cisapride concentrations in blood samples drawn over 48 hours were measured by high-performance liquid chromatography. Individual and mean values for bioavailability parameters were subjected to analysis of variance followed by multiple comparison testing. Time to maximum concentration was shortest after administration of the solution. There was a significant difference in mean peak plasma concentrations between treatment A (48.8±12.8 ng/mL) and treatment D (41.6±10.6 ng/mL), with treatment A producing a 17.3% higher peak concentration. No significant differences between treatments were found for area under the plasma concentration-time curve. The overall mean elimination half-life was 7.01 hours. The results of the study indicate that the tablet and suspension dosage forms of cisapride are bioequivalent to the reference solution.