Bioequivalence study of vardenafil hydrochloride tablets in Chinese healthy subjects
Objective To evaluate the bioequivalence of the vardenafil hydrochloride tablets in fasting and fed conditions in healthy Chinese adult subjects with the test and reference formulations.Methods A randomized,open,single-dose,two-preparation,two-sequence,two-period,crossover design was used,and 40 healthy male subjects enrolled in the fasting state and 66 healthy male subjects enrolled in the fed state.The trial was conducted in two cycles,with 20 mg of either the subject formulation or the reference formulation,vardenafil hydrochloride tablets,being administered in each cycle.The drug concentration of vardenafil in plasma was determined by the liquid chromatography-tandem mass spectrometry(LC/MS-MS)method.Pharmacokinetic parameters were calculated using the non-compartment model,and the safety evaluation indexes were statistically analyzed using SAS 9.4 or above version program data statistical software.Results Arithmetic mean values of the main pharmacokinetic parameters of the subject formulation of vardenafil hydrochloride tablets and the reference formulation in the fasting state:Cmaxwere(34.94±18.33)and(36.69±19.45)ng·mL-1;AUC0-t were(74.38±34.11)and(74.25±33.37)ng·mL-1·h;AUC0-∞ were(76.70±34.36)and(76.46±33.84)ng·mL-1·h,respectively.Arithmetic mean values of the main pharmacokinetic parameters of the subject formulation of vardenafil hydrochloride tablets and the reference formulation in the fed state:Cmax were(22.84±12.48)and(21.68±11.12)ng·mL-1;AUC0_twere(70.82±35.88)and(72.71±34.63)ng·mL-1·h;AUC0-∞ were(73.48±36.44)and(75.29±35.12)ng·mL-1·h,respectively.The 90%confidence intervals for the geometric mean ratios of the main pharmacokinetic parameters such as Cmax,AUC0-t and AUC0-∞ of the prototype drug vardenafil in plasma after oral administration of 20 mg of the test and reference formulations of vardenafil tablets to the subjects in fasting and postprandial states fell within the equivalence interval of 80.00%to 125.00%.Conclusion The subject formulation of vardenafil hydrochloride tablets was bioequivalent to the reference formulation in fasting and fed conditions in healthy Chinese subjects.
vardenafil hydrochloride tabletpharmacokineticsbioequivalenceliquid chromatography-tandem mass spectrometry