Performance liquid chromatographic analysis of glipizide: application to in vitro and in vivo studies

This paper describes the validation of a sensitive, accurate, and reproducible method for the determination of a release profile of glipizide from controlled-release dosage forms. In this method, an in vitro dissolution profile of commercial controlled-release dosage forms is determined using a reversed-phase C(18) column, mobile phase (acetonitrile-buffer, 0.05 M KH(2)PO(4) adjusted to pH 3.5 with orthophosphoric acid), and UV detection at a wavelength of 275 nm. The method is validated for linearity, accuracy, precision, and detection and quantitation limits. The same method can be exploited to determine the plasma concentration of glipizide. The peak area versus plasma concentration is linear over the range of 12.5-1000 ng/mL and the detection limit was 5 ng/mL in plasma. The average accuracy was 99.90% with a relative standard deviation (RSD) of not more than 3%. Repeatability and reproducibility were found to be good with an RSD of less than 3%.