Bioequivalence study of ondansetron tablet in healthy Thai male volunteers.

ABSTRACT

OBJECTIVES: To assess the average bioequivalence of two formulations of 8-mg ondansetron tablets--test product (Unison Laboratories, Thailand) and reference product (Glaxo Wellcome, USA)--in 14 healthy Thai male volunteers. MATERIAL AND METHOD: In a randomized, single dose, fasting, two-period, crossover study design with a 1-week washout period, each subject received an 8-mg ondansetron tablet. Serum samples were collected over a 24-hour period after administration. Subsequently serum concentrations of ondansetron were analyzed by using a validated HPLC-UV method. Pharmacokinetic parameters were determined by using non-compartmental analysis. RESULTS: No significant difference was observed in any of the pharmacokinetic parameters analyzed. The time to reach the maximal concentration (Tmax, hour), the peak concentration (Cmax, ng/ ml) and the area under the concentration-time curve (AUC(0-infinity), ng x h/ml) of ondansetron for reference and test preparations were 2.6 + 1.8 vs 2.2 + 0.6, 49.5 +/- 18.9 vs 48.5 +/- 13.7 and 352.2 +/- 184.7 vs 323.8 +/- 154.5, respectively. The 90 per cent confidence intervals for Test/Reference ratio of Cmax and AUC(0-infinity) were found within the bioequivalence range of 80-125 per cent (90.3-110.0% and 88.4-99.6%, respectively). CONCLUSION: The bioequivalence of these two ondansetron preparations was demonstrated.