extraction and determination of fexofenadine and levocetirizine in human plasma by hollow fiber liquid phase microextraction and high performance liquid chromatography

a simple, inexpensive and efficient method was used for extraction and determination of fexofenadine and levocetirizine with three–phase hollow fiber liquid-phase microextraction and high-performance liquid chromatography. several parameters influencing the extraction recoveries such as the nature of organic extraction solvent, ph of donor and acceptor phases, stirring rate, extraction time and salt addition to the sample solution (donor phase) were investigated and optimized. under the optimized conditions (toluene as organic solvent, phdonor = 2.5, phacceptor = 12.0, stirring rate of 1000 rpm, extraction time of 30 min, with no salt addition), extraction recoveries were 64% for fexofenadine and 79% for levocetirizine. a good clean-up sample with excellent linearities in the range of 1–500 ng/ml for fexofenadine (r2=0.997) and 0.6-600 ng/mlfor levocetirizine (r2=0.998) were obtained. the limits of detection were 0.3 ng/ml for fexofenadine and 0.2 ng/ml for levocetirizine.