A Simple, Specific, and Rapid High Performance Liquid Chromatographic Assay for Glibenclamide in Plasma

Abstract

A simple, rapid, sensitive and relatively specific reverse phase HPLC assay procedure for glibenclamide in rat and human plasma is described. The method employs considerably smaller sample volume (0.2 ml) and a single step extraction with dichloromethane. A relatively high degree of sensitivity (detection limit of the assay was 20 ngml⁻¹) was obtained by using fluorescence detection at excitation and emission wavelengths of 308 and 360 nm, respectively. The mean percentage recovery of the drug in the concentration range of 30–120 ng was 100.6% while the between-day coefficient of variation for the same concentration range was 7.29%.

The assay procedure offers a much better degree of resolution for the glibenclamide peak than was previously reported. This was achieved through the use of a chromatographic column with a finer packing material (Novapak C₁₈, 4 μm) and by selecting the ideal composition, pH and elution rate of the mobile phase—methanol: 0.05 M potassium dihydrogen phosphate (61:39 v/v, pH 4 and pumped at 1.2 ml.min⁻¹).

It is hoped that this micro assay technique will find wider application in both clinical and subclinical pharmacokinetic studies involving glibenclamide.