HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC METHOD FOR DETERMINATION OF GLIBENCLAMIDE IN HUMAN PLASMA

An HPLC method for quantitative determination of glibenclamide in huma n plasma is described. The methodology is based on simple one step ext raction of glibenclamide and diazepam (internal standard) from human p lasma with dichloromethane. The drugs were eluted from a resolve 5 u s pherical C-18 column with a mobile phase consisting of 0.05 hydrogen p hosphate:methanol (40:60%, v/v) justed to pH 4.0 with phosphoric acid. The drug and the internal standard were eluted at a flow rate of 1.2 mi per minute, and the optimum detector wavelength was 230 nm. The chr omatography time was eleven minutes and the resolution between the dru g and internal standard was excellent. Quantitation was achieved by th e measurement of peak area ratios and the minimum detectable concentra tion was 5 ng/ml. The calibration curve of the assay was linear over t he range of 10-400 ng/ml, The intraday coefficient of variation were r anged from 0.53% to 3.19%, whereas interday coefficient of variation w ere from 2.31% to 7.90%. The relative and absolute recoveries varied b etween 91.7% and 101.5%. Stability results showed that glibenclamide i s stable for at least 10-weeks in plasma when freezed at -20 degrees C . The utility of the analytical methodology for the quantitative deter mination of glibenclamide in pharmacokinetic studies in the human plas ma was demonstrated.