Pharmacokinetic analysis of febuxostat in human serum by UFLC based on fluorimetric derivatization

Abstract

An ultra fast liquid chromatographic (UFLC) method using fluorimetric detection for the quantitation of Febuxostat (FEB) in human serum was developed by precolumn derivatization with 4-bromomethyl-7-methoxy coumarin (BrMmC). The derivatization was catalyzed with dibenzo-18-crown-6-ether to produce a fluorescent derivative which was determined through fluorescence measurement with excitation at 320 nm and emission at 395 nm wavelengths. A C18 column with 100 cm x 4.6 mm, 3 µm particule size was used for the UFLC separation procedure. A mixture of acetonitrile: methanol: 0.05 M aqueous ammonium acetate (pH 5.0) (40:40:20, v/v/v) was used as mobile phase. During the procedure, the flow rate was maintained at 0.5 mL/min. A calibration curve was then plotted as 0.005–3.0 µg/mL with a detection limit of 0.0022 µg/mL and quantification limit of 0.0073 µg/mL. The mean recovery to reveal the accuracy and relative standard deviation (RSD) that indicates the precision of the method were found out to be 85.20 % and less than 3.52 %, respectively. The utility of the new method has been demonstrated by measuring the pharmacokinetics of FEB by administration of 80 mg tablets to a healthy female volunteer, aged 42.