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A selective, rapid and sensitive reverse phase ultra- performance liquid chromatography method was developed for the quantitative determination of fexofenadine in human plasma. With carbamazepine as internal standard, sample pretreatment involved a one-step extraction with ethyl acetate from 980µl plasma. The sample was analyzed using 10mM KH2PO4 buffer pH 2.5 and acetonitrile (70:30 v/v) as mobile phase. Chromatographic separation was achieved on an ACQUITY UPLC BEH (C-18) column using isocratic elution. The peak was detected using UV-PDA detector set at 210 nm and the total time for chromatographic separation was 10 min. Linear calibration curves were obtained in the concentration range of 30.09-1805.39 ng/ml with a lower limit of quantification of 30.09 ng/ml. The inter and intra- day precision (RSD) values were below 15% and accuracy (RE) was from 1.55 to 5.51 % at all QC levels. Developed method was found to be accurate, precise, selective and rapid for estimation of fexofenadine in plasma and can be used for pharmacokinetic and bioequivalence studies.

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