Liquid chromatographic determination of glibenclamide in human plasma

The oral hypoglycemic agent glibenclamide was determined in human plasma by liquid chromatography (LC). Samples, with internal standard added, are extracted with dichloromethane. The organic phase is evaporated, and the residue is reconstituted in mobile phase for injection onto the LC column. Intra- and inter-day variability of the method was assessed at high and low levels of the drug. Although coefficients of variation were similar for both intra- and inter-day studies at both levels, CVs were smaller at the higher concentration level. Recovery of the drug was good at both high and low levels. The minimum level of detection was 5 ng/mL.