Simultaneous Quantification of Glibenclamide, Simvastatin, and Quercetin by Using LC-UV Method and Its Application to Pharmacokinetic Study in Rats

A sensitive, precise, and simple LC method for the simultaneous quantification of glibenclamide, simvastatin, and quercetin in rat plasma has been developed and validated. The chromatographic separation was achieved on a cyano column (250 mm × 4.6 mm, 5 µm) maintained at room temperature, using isocratic elution with methanol : acetonitrile : 10 mM potassium dihydrogen orthophosphate, pH adjusted to 4.5 with o-phosphoric acid (8 : 32 : 60, v/v) and detected using UV-VIS detector. Plasma samples were deproteinated with 0.1% perchloric acid and acetonitrile for extraction of the glibenclamide, simvastatin, and quercetin which resulted in their high recoveries. LC calibration curves based on the extracts from the rat plasma were linear in the range of 50–1000 ng mL−1 for all the three drugs. The limit of quantification was 50 ng mL−1. The described method was successfully applied to study the pharmacokinetics of glibenclamide, simvastatin, and quercetin following oral administration, in combination to Sprague-Dawley rats.