Pharmacokinetic studies of metformin and glibenclamide in normal human volunteers

The study was aimed to evaluate various pharmacokinetic parameters of a commercially available fixed dose combination of oral antidiabetics (metformin/glibenclamide 500/5mg tablets) in plasma sample of normal healthy adult male volunteers by applying an accurate, selective, and reproducible hplc-uv analytical method for quantification of metformin hcl and glibenclamide simultaneously in a single chromatographic run. previously no hplc-uv analytical method for simultaneous estimation of metformin/glibenclamide has been reported in pakistan. the human plasma samples were evaluated by using an isocratic high performance liquid chromatography (hplc) system of sykam consisted of a pump with a column of thermo electron corporation usa (ods hypersil c18 4.6 mm x 250 mm), a uv-detector with data processing clarity software. the mobile phase of 0.040m potassium dihydrogen phosphate containing 0.25ml/l triethylamine at ph 3.5 (adjusted with 1:1 phosphoric acid) and acetonitrile (465: 535v/v) was delivered with injection volume of 100μl at flow rate of 1 ml/min at 25°c temperature. the detection was performed at λmax230 nm. by applying this method, important pharmacokinetic parameters cmax, tmax, auc0-∞, aumc0-∞, t1/2, ke, mrt, vd and clt are calculated. maximum plasma concentrations cmax was 131.856±8.050ng/ml for glibenclamide (mean ± sem) and 511.106±12.675 ng/ml for metformin hcl (mean ±sem).