No abstract

We report the first investigational electrochemical study for Remdesvir (REM), a promising antiviral agent used recently for the treatment of COVID-19. An anionic surfactant, silica nanoparticles, and multiwall carbon nanotubes carbon paste (SDS/SiO2/MWCNT/CPE) sensor was designed to introduce our approach. The results revealed irreversible diffusion oxidative reaction of REM with two well-defined peaks (E1/V=1.19, E2/V=1.35) in 0.1 M phosphate buffer of pH 6 using differential pulse (DP) voltammetry. A linear relationship between the peak current and the drug concentration was established over the concentration range of 1.66 x 10-7 - 3.52 x 10-6 M (100-200 ng/mL) with a limit of detection (LOD) of 4.80 x 10-8 M and limit of quantitation (LOQ) of 8.0 x 10-8 M and mean % recovery ± % RSD of 99.05 ± 1.94. The proposed method succeeded in determination of the drug in its pharmaceutical dosage form, in human plasma, and in human urine samples. Finally, the method was validated according to ICH guidelines and FDA guidance for the determination of the drug in biological fluids. The developed data was found to be in good agreement with a validated reported method.

Objectives:In this work we presented a highly sensitive, selective and validated method for determination of tedizolid phosphate (TEDP) antibiotic, based on its native fluorescence in aqueous solution. Methods: The maximum fluorescence intensity was measured at 408 nm after excitation at 298 nm after optimization of all experimental conditions. Results:The measured fluorescence was directly proportional to the concentration of the drug over the range of 2-30 ng/mL with a limit of detection of 0.13 and limit of quantification of 0.44 ng/mL The method succeeded to determine TEDP in its pharmaceutical dosage form and in human plasma with mean % recovery of 100.49 ±1.32 and 99.40 ± 2.18 respectively. Conclusion:The developed data was found to be with a good agreement with a valid method. The method was validated according to ICH guidelines for determination of the drug in its pure form and dosage form and according to FDA Guidance for Industry, Bioanalytical Method Validation for determination of TEDP in human plasma.