Development and validation of RP-HPLC-UV method for the determination of Glipizide in human plasma

A simple, sensitive and selective HPLC method with UV detection for determination of Glipizide in human plasma was developed. Liquid-liquid extraction method was used to extract the drug from the plasma samples. Chromatographic separation of Glipizide was achieved using C18 column (ZORBAX ODS 4.6 × 150 mm). The mobile phase was comprised of 0.01 M potassium dihydrogen phosphate and acetonitrile (65:35, v/v) adjusted to pH 4.25 with glacial acetic acid. The analysis was run at a flow rate of 1.5 mL/min with an injection volume was 20 μL. The detector was operated at 275 nm. The calibration curve was linear over a concentration range of 50-1600 ng/mL. Intra-day and inter-day precision and accuracy values were below 15%. The limit of quantification was 50 ng/mL and the mean recovery was above 98%. Freeze-thaw, short-term, long-term and post-preparative stability studies showed that Glipizide in plasma sample was stable. The method may be successfully applied to analyze the Glipizide concentration in plasma samples for bioavailability and bioequivalence studies.