Study on relative bioavailability and pharmacokinetics of metformin hydrochloride sustained-release tablets in healthy dogs

OBJECTIVE The relative bioavailability between metformin hydrochloride (MH) sustained-release tablets and commercial tablets and the pharmacokinetics were studied in 6 healthy dogs. METHODS The study was conducted in a two-treatment,two-period,two-sequence randomized cross-over trial. The plasma concentration of MH after an oral single-dose in the subjects was determined by HPLC.The important pharmacokinetic parameters were caculated. RESULTS From the plasma concentration-time data of both preparations in the single-dose study,the t 1/2(ke)、k e、t max、C max and AUC 0-∞ for metformin hydrochloride sustained-release tablets and commercial tablets were( 8.3± 2.8) and ( 3.8± 2.1)h,( 0.09± 0.03) and ( 0.24± 0.13) h -1,( 3.3± 0.8) and ( 1.5± 0.8)h,( 9.8± 3.5) and ( 14.6± 4.3)mg·L -1,( 70.2± 33.5) and ( 62.5± 23.3) mg·h·L -1,respectively. A adequate ANOVA analysis showed that there was no significant difference (P 0.05) between them. The relative bioavailability of the metformin hydrochloride (MH) sustained-release tablet was 112.3%.CONCLUSION These two dosage forms were bioequivalent.