Development of a high-performance liquid chromatography method for simultaneous determination of pioglitazone and felodipine in pig serum: application to pharmacokinetic study.

A simple and sensitive high-performance liquid chromatographic method was developed and validated for simultaneous estimation of pioglitazone and felodipine in pig serum. The present method consists of protein precipitation, extraction of analytes from pig serum into dichloromethane and separation using reversed-phase C(18) column. Nitrendipine was used as an internal standard and the eluent was monitored by UV detector at 240 nm. The mobile phase used was acetonitrile and 50 mm ammonium acetate buffer at a flow rate of 1 mL/min. The retention times for pioglitazone, felodipine and nitrendipine were found to be 5.12, 10.53 and 7.14 min, respectively. The intraday and inter-day coefficient of variation and percent error values of assay method were less than 7% and mean recovery was more than 94% for each analyte, and the method was found to be precise, accurate and specific during study. The method was successfully applied for pharmacokinetic study of pioglitazone and felodipine from bioadhesive buccal tablet after buccal administration to pigs. The C(Max) , T(Max) , and AUC(0-24) of pioglitazone and felodipine from buccal tablet were found to be 394.6 ng/mL, 5.6 h, 2624.2 ng h/mL and 44.4 ng/mL, 5.5 h, 275.8 ng h/mL, respectively.