Study on fluorescence properties of HCV antiviral (velpatasvir) and its fluorimetric determination in presence of sofosbuvir; application to stability study and human plasma

Abstract

Velpatasvir (VLP) is a new, oral, direct-acting antiviral with potent inhibitory activity against all hepatitis C virus (HCV) genotypes. A highly sensitive, simple, fast and specific one fluorometric method for determination of VLP in the presence of sofosbuvir was developed and validated. The fluorescence behavior of VLP in different organic solvents was examined and explained. Methanol was concluded to be the best sensitizing reagent. The native fluorescence intensity of VLP was accomplished at 383 nm with 339 nm for excitation wavelength. The impacts of experimental variables included pH, various organized media, and time of stability were examined and optimized. A linear relationship was achieved between the VLP concentration and the fluorescence intensity in a range of 5 to 5 × 10 ng mL with 0.70 and 0.23 ng mL , for quantitation and detection limits respectively. The proposed method was utilized for analyzing of VLP in human plasma and additionally expanded to examine the stability of VLP after its exposure to various stress conditions, like oxidative, alkaline, acidic, UV, daylight and sunlight conditions, according to ICH guidelines. Furthermore, the kinetics of acidic and oxidative degradations of VLP was examined. Moreover, the half-life times of the reaction (t ) and the first-order reaction rate constants were estimated. Finally, a suggestion for the degradation pathway was presented.

Thin‐layer chromatography/fluorescence detection approach for sensitive and selective determination of hepatitis C virus antiviral (velpatasvir): application to human plasma

“…VLP has strong native fluorescence properties [ 15 ] and therefore the drug could be determined using the fluorescence reflection mode (with excitation wavelength of 335 nm) after separation on TLC plates.…”

Microenvironment improvement protocol for the sensitive spectrofluorimetric determination of an hepatitis C virus antiviral (Simeprevir): application to human plasma

“…The use of micellar media has become one technique that is commonly applied to enhance the fluorescence emission of many fluorophores and therefore could successfully decrease the limit of detection (LOD) of the method. This approach has been applied to improve the sensitivity of the spectrofluorimetric analysis of several compounds . As presented in Figure , SPV has weak inherent fluorescence in aqueous solution at λ em 427 nm after excitation at λ ex 337 nm.…”

Novel spectrofluorimetric approach for determination of ledipasvir through UV-irradiation: application to biological fluids, pharmacokinetic study and content uniformity test

“…10,11 The spectrouorometric technique is one of the well-known analytical tools that provide the goal of increasing the method simplicity, selectivity and sensitivity without loss of precision. 16 In spite of the reported spectrouorimetric methods [12][13][14] were applied for the determination of LDS in the plasma and tablets but they not extended to pharmacokinetic study and content uniformity test of LDS by this technique. Moreover, up till now the determination of LDS in the faecal samples (the major excretion route for LDS 5 ) was not reported by any technique.…”