An uplc method for the determination of sorafenib in human plasma by fluorimetric detection with pre-column derivatization and application to a pharmacokinetic study

This research presents a new, sensitive and selective UPLC method with fluorometric detection for the determination of sorafenib in human plasma and application of the method to a pharmacokinetic study. Sorafenib was precolumn derivatized with 7-chloro-4-nitrobenzofurazan (NBD-Cl) and the separation of the fluorescent derivative was performed with a C18 column (50 mm x 2.1 mm, 1.7 mu m) at 40oC using a mobile phase composed of acetonitrile -0.1% trifluoroacetic acid in water (60:40, v/v) by isocratic elution with flow rate of 0.5 mL min-1. The injection volume was 7 mu L. The method depends on the measurement of the derivative using fluorescence detection (lambda ex = 398 nm, lambda em = 425 nm). The retention time of sorafenib was 3.10 +/- 0.02 min. The novel method was validated in accordance with ICH criteria by studying on the parameters such as specificity, linearity, precision, accuracy and robustness. The method was determined to be linear in a concentration range of 0.25-10 mu g mL(-1) with the correlation coefficient of 0.9995. Limit of detection and quantitation were found to be 0.075 and 0.25 mu g mL-1, respectively. Intraday and interday RSD values were less than 5.48%. The plasma concentration-time profile and pharmacokinetic parameters such as AUC0-t, AUC0-& INFIN;, Cmax, tmax, t1/2 were measured according to the assays. The proposed method is feasible to investigate the bioequivalence and bioavailability and routine analysis of the drug in plasma.