[Fluorometric determination of glibornuride in plasma and serum using 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole]

Glibornuride, tolbutamide and gilbenclamide react on heating with 7-chloro-4-nitrobenzo-2-oxa-1.3-diazole (NBD-chloride) in amylacetate to form a highly fluorescent NBD-amine. A fluorometric determination of glibornuride is presented. Reaction conditions and the extraction of glibornuride from plasma and serum are described. The method is sensitive to measure drug levels after therapeutic doses. The detection limit is ca. 40 ng/ml and the recovery rate is ca. 100%. The coefficients of variation for the determination of drug levels of 1 to 0.1 mug/ml range from 4.1% to 12.1%.