Bioequivalence of glipizide controlled-release tablets in Chinese healthy volunteers

Objective To study the relative bioavailability and bioequivalence of two glipizide controlled -release preparations in healthy volunteers.Methods The tests were carried out according to single dosage regimen and multiple dosage regimen in a open crossover design. In single dosage regimen, 24 enrolled healthy volunteers were randomized given 5mg of test or reference preparation.In multiple dosage regimen,22 enrolled subjects were given 5 mg of test or reference preparation once daily for 7 consecutive days. LC-MS/MS was used to determine the glipizide concentration in serum. Pharmacokinetic parameters and relative bioavailability were calculated, and bioequivalence of the two preparations was evaluated.Results The main pharmacokinetic parameters were calculated as follows:In single dosage regimen, for reference and test preparations, t1/2β were (9.12±2.73), (8.60±4.43)h ;tmax were (10.67±5.13), (9.08±2.76)h;Cmax were (135.9 ±41.1),(157.9±25.3)ng·mL-1;AUC0-48 were (2852.0±946.6), (3021.5±899.9)ng·h·mL-1;AUC0-∞ were (3002.4±1107.6), (3167.6±1090.6) ng·h·mL-1 respectively. The relative bioavailability was (109.2 ±25.4)%.In multiple dosage regimen,for reference and test preparations, t1/2β were (11.31±3.37), (10.97±3.49 )h; tmax were (6.8 ±3.5), (6.6±3.7) h; Cssmax were (187.4±54.5), (176.0±72.3) ng·mL; Cssmin were (61.3 ±28.1), (69.1±41.2 )ng·mL; AUC0-48 were (3495.0 ±1110.6), (3488.2±1554.9)ng·h·mL-1;AUC0-∞ were (3670.7±1199.7), (3650.5±1599.2) ng·h·mL-1,respectively. The relative bioavailability was (101.0 ±32.1)%.DF were (56.2 ±19.9)%,(49.7±22.5)% for reference and test preparation,respectively.Conclusion The two preparations were bioequivalent.