Development and validation of a liquid chromatography-tandem mass spectrometry method for the determination of febuxostat in human plasma.
ABSTRACT A rapid and sensitive analytical method based on liquid chromatography coupled to tandem mass spectrometry detection with positive ion electrospray ionization was developed for the determination of febuxostat in human plasma using d(7) -febuxostat as the internal standard (IS). A simple protein precipitation was performed using acetonitrile. The analyte and IS were subjected to chromatographic analysis on a Capcell PAK C(18) column (4.6 × 100 mm, 5 µm) using acetonitrile-5 mm ammonium acetate-formic acid (85:15:0.015, v/v/v) as the mobile phase at a flow rate of 0.6 mL/min. An Agilent 6460 electrospray tandem mass spectrometer was operated in the multiple reaction monitoring mode. The precursor-to-product ion transitions m/z 317 → m/z 261 (febuxsotat) and m/z 324 → m/z (261 + 262) (d(7) -febuxostat, IS) were used for quantitation. The results were linear over the studied range (10.0-5000 ng/mL), and the total analysis time for each chromatograph was 3 min. The intra- and inter-day precisions were less than 7.9 and 7.2%, respectively, and the accuracy was within ±4.2%. No evidence of analyte instability in human plasma was observed storage at -20°C for 31 days. This method was successfully applied in the determination of febuxostat concentrations in plasma samples from healthy Chinese volunteers. Copyright © 2012 John Wiley & Sons, Ltd.
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ABSTRACT: A bioequivalence study was proved of generic Febuxostat 80 mg tablets (T) in healthy volunteers.For this purpose, Authors developed a simple, sensitive, selective, rapid, rugged and reproducible liquid chromatography-tandem mass spectrometry method for the quantification of Febuxostat (FB) in human plasma using Febuxostat D7 (FBD7) as an internal standard (IS) was used. Chromatographic separation was performed on Ascentis Express C18 (50x4.6 mm, 3.5 μ) column. Mobile phase composed of 10 mM Ammonium formate: Acetonitrile (20:80 v/v), with 0.8 mL/min flow-rate. Drug and IS were extracted by Liquid- liquid extraction. FB and FBD7 were detected with proton adducts at m/z 317.1→261.1 and 324.2→262.1 in multiple reaction monitoring (MRM) positive mode respectively. The method was validated with the correlation coefficients of (r(2)) ≥ 0.9850 over a linear concentration range of 1.00-8000.00 ng/mL. This method demonstrated intra and inter-day precision within 2.64 to 3.88 and 2.76 to 8.44% and accuracy within 97.33 to 99.05 and 100.30 to 103.19% for FB. This method is successfully applied in the Bioequivalence study of 9 human volunteers.SpringerPlus 12/2013; 2(1):194.
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ABSTRACT: Background: Due to wide consumption of flavonoids in the dietary supplement, and an imperative role of CYPs and P-glycoprotein inhibition in drug disposition. So there is increasing scientific interest in drug-flavonoid interactions. Objective: The present study aims to investigate the effect of morin, a flavonoid, on the pharmacokinetics of febuxostat in rats. Methods: A simple ultra-performance liquid chromatography method has been developed for the calculation of febuxostat in 100 µl rat plasma using febuxostat D7 as an internal standard (IS). The assay procedure involved a single-step, liquid-liquid extraction of febuxostat and IS from plasma with methanol. Pharmacokinetic parameters of febuxostat were determined in rats after an oral administration of febuxostat (5 mg/kg) to rats in the control, coadministered and pretreated groups of morin (10 mg/kg). Results: Compared to the control rats given febuxostat alone, the Cmax and AUC of febuxostat increased by 18 - 20 and 47 - 50%, respectively, in rats pretreated with morin. The plasma half-life (t1/2) of the pretreated group is increased by 2.5-fold compared with the control group. Consequently, relative bioavailability values of febuxostat in the rats pretreated with morin were significantly higher (p < 0.05) than those from the control and coadministered groups. Increased bioavailability indicates that the presence of morin could be effective in inhibiting CYP1A1, CYP1A2 and CYP3A4-mediated metabolism and/or effective in inhibiting P-glycoprotein-mediated cellular efflux of febuxostat. Conclusion: The presence of morin significantly enhanced the oral exposure of febuxostat, suggesting that concurrent use of morin or morin-containing dietary supplements with febuxostat should be verified to avoid drug-flavonoid interactions.Expert Opinion on Drug Metabolism & Toxicology 02/2014; · 2.94 Impact Factor
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ABSTRACT: An improved, simple and highly sensitive LC-MS/MS method has been developed and validated for quantification of febuxostat with 100 μL human plasma using febuxostat-d7 as an internal standard (IS) according to regulatory guidelines. The analyte and IS were extracted from human plasma via liquid-liquid extraction using diethyl ether. The chromatographic separation was achieved on a Zorbax C18 column using a mixture of acetonitrile and 5 mm ammonium formate (60:40, v/v) as the mobile phase at a flow rate of 0.5 mL/min. The total run time was 5.0 min and the elution of febuxostat and IS occurred at 1.0 and 1.5 min, respectively. A linear response function was established for the range of concentrations 1-6000 ng/mL (r > 0.99). The precursor to product ion transitions monitored for febuxostat and IS were m/z 317.1 → 261.1 and 324.2 → 262.1, respectively. The intra- and inter-day precisions (%RSD) were within 1.29-9.19 and 2.85-7.69%, respectively. The proposed method was successfully applied to pharmacokinetic studies in humans. Copyright © 2013 John Wiley & Sons, Ltd.Biomedical Chromatography 06/2013; · 1.95 Impact Factor