Fluorimetric determination of febuxostat in dosage forms and in real human plasma via Förster resonance energy transfer

Abstract

A rapid, simple, selective and precise fluorimetric method was developed and validated for determination of a selective xanthine oxidase inhibitor; febuxostat (FBX) in pharmaceutical formulations and in human plasma. The proposed method is based on quenching effect of FBX on the fluorescence intensity of terbium (Tb ) through fluorescence resonance energy transfer (FRET) from Tb to FBX. The formed complex was measured at λ 320 nm/λ 490 nm against a reagent blank. Fluorescence intensity of Tb was diminished when FBX was added. A linear relationship between the fluorescence quenching value of the formed complex ΔF=FTb3+-FFBX-Tb3+ and the concentration of FBX was investigated. The reaction conditions and the fluorescence spectral properties of the complex have been studied. The linearity range of the developed method was 1.0-16.0 μg/ml. The suggested method was applied successfully for the estimation of FBX in bulk powder, dosage forms and spiked plasma samples with excellent recoveries (96.79-98.89%). In addition, the developed method has been successfully applied for determination of FBX in real plasma samples collected from healthy volunteers with good recoveries (82.06-85.65%). All obtained results of the developed method were statistically analyzed and validated according to ICH (International Conference on Harmonization) guidelines.

Combined experimental/computational aspects for the molecular interaction of empagliflozin with bovine serum albumin: Quantification and application to human plasma

“…FRET phenomenon is widely applied for both the determination of the distance between the donor (fluorophore) and acceptor (quencher) molecules and the estimation of the energy transfer efficiency [22, 30, 31]. By plotting an overlay of the normalized emission spectrum of BSA (3.0 μM) in Tris–HCl buffer and the normalized excitation spectrum of EMP (20.0 μM) under the same experimental and instrumental settings (Figure S3), spectral overlap integral (J) was 3.16 × 10 16 M −1 cm −1 nm 4 , calculated from the following equation (Equation 5) [31]: where F (λ) represents the BSA fluorescence intensity and ɛ (λ) stands for the EMP molar absorption coefficient (L/mol cm) at wavelength λ.…”

“…FRET phenomenon is widely applied for both the determination of the distance between the donor (fluorophore) and acceptor (quencher) molecules and the estimation of the energy transfer efficiency [22,30,31]. By plotting an overlay of the normalized emission spectrum of BSA (3.0 μM) in Tris-HCl buffer and the normalized excitation spectrum of EMP (20.0 μM) under the same experimental and instrumental settings (Figure S3), spectral overlap integral (J) was 3.16 Â 10 16 M À1 cm À1 nm 4 , calculated from the following equation (Equation 5) [31]:…”

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

“…Febuxostat (FEB), a novel non-purine selective inhibitor of xanthine oxidase, which is used for the treatment of hyperuricaemia in gout. 1 In the literature, several methods of FEB analysis have been described in different matrices including spectrophotometric, 2-4 spectrofluorimetric, [5][6][7] high performance liquid chromatographic methods in combination with UV, 8,9 fluorimetric, 10 mass (MS) [11][12][13] and tandem mass MS/MS detections, 14 and a capillary chromatographic method.…”

Two different synchronous spectrofluorimetric approaches for simultaneous determination of febuxostat and ibuprofen

“…From the literature survey, the analysis of FEB was performed using different methods including spectrofluorimetry [10][11][12][13], spectrophotometry [14,15], HPLC [9,[16][17][18][19], LC-MS [20][21][22], micellar electrokinetic capillary chromatography [23], HPTLC [24][25][26][27] and GC [28]. Similarly, the assay of IBU has been achieved applying different methods including spectrofluorimetry [29][30][31][32], spectrophotometry [33,34], HPLC [35][36][37], LC-MS [38,39], HPTLC [37], capillary zone electrophoresis [40,41], potentiometry [42] and GC [43,44].…”