Pharmacokinetics of metformin gastric-retentive tablets in healthy volunteers

The single-dose pharmacokinetics of two gastric-retentive, extended-release tablet formulations of metformin hydrochloride in fed, healthy volunteers were compared with those of the currently marketed immediate-release metformin hydrochloride product. The plasma concentration-time profiles demonstrated extended-release characteristics from the gastric-retentive tablets. The mean bioavailability from each gastric-retentive tablet was approximately 115%, relative to the immediate-release (IR) product. C-max values were lower and t(max) values were greater for the gastric-retentive tablets compared with the IR product. In contrast to conventional extended-release metformin tablets reported in the literature, these gastric-retentive tablets showed extended-release plasma concentration profiles of metformin hydrochloride and increased bioavailability compared with the immediate release tablet.