Nagaraj P. Shetti

Electrochemical behavior of an anticancer drug 5-fluorouracil at methylene blue modified carbon paste electrode

A novel sensor for the determination of 5-fluorouracil was constructed by electrochemical deposition of methylene blue on surface of carbon paste electrode. The electrode surface morphology was studied using Atomic force microscopy and XRD. The electrochemical activity of modified electrode was characterized using cyclic voltammetry and differential pulse method. The developed sensor shows impressive enlargement in sensitivity of 5-fluorouracil determination. The peak currents obtained from differential pulse voltammetry was linear with concentration of 5-fluorouracil in the range 4×10(-5)-1×10(-7)M and detection limit and quantification limit were calculated to be 2.04nM and 6.18nM respectively. Further, the sensor was successfully applied in pharmaceutical and biological fluid sample analysis.

Electro-sensing base for mefenamic acid on a 5% barium-doped zinc oxide nanoparticle modified electrode and its analytical application

In the present work, surface enhanced electro-oxidation of mefenamic acid (MFA) at a glassy carbon electrode modified with 5% barium doped ZnO nanoparticles was studied. Cyclic voltammograms with a maximum peak current at pH 5 in the pH range of 3.0–11.0 were recorded at a scan rate of 50 mV s−1, with a distinct oxidation peak in the range of 0.2–1.0 V (versus Ag/AgCl). Two protons and electrons accompanied the electrode reaction. Based on the experimental results, a possible electro-oxidation mechanism for MFA was proposed. Quantitative analysis of MFA was carried out using a differential-pulse voltammetric method (DPV). Linearity was observed in the range of 500 nM to 10.0 × 103 nM. LOD and LOQ were calculated to be 6.02 nM and 20 nM, respectively. In addition, the developed method was used in the in vitro analysis of MFA in pharmaceutical formulations and spiked human urine samples.

Electrochemical oxidation of loop diuretic furosemide in aqueous acid medium and its analytical application

Abstract An investigation of oxidative–reductive mechanisms of pharmaceutically important molecules gives us information about the metabolic fact of targeted drug. As compared to recent ongoing, time-consuming and costly techniques, there is an urgent needing for development of a sensitive technique, which can help easy understanding of these pathways. Therefore, in the present work, an effective, low-cost and time-saving technique to investigate the reaction mechanism of furosemide in aqueous acid medium is attempted. Furosemide undergoes two-proton and two-electron transfer reaction. The product obtained was analysed by UV spectra. It was found that the chemical oxidation and electrochemical oxidation of furosemide follows two different pathways. In addition, an effective technique has been developed to determine furosemide in its trace level. Good recoveries and low detection limit accomplished the magnitude of the proposed method. The proposed method was adopted for furosemide determination in human urine and pharmaceutical samples.

Electrooxidation of antihistamine drug methdilazine and its analysis in human urine and blood samples

Abstract The electrochemical oxidation of an antihistamine drug, methdilazine, was studied in 9.2 pH with 0.2 M phosphate buffer as supporting electrolyte at 25 ± 0.2°C. Glassy carbon electrode was used to perform the experiment at cyclic voltammetry, linear sweep voltammetry and differential pulse voltammetric techniques. The dependence of the current on pH, concentration and scan rate were investigated. Differential pulse voltammetric technique was adopted to know the linear relation between peak current and methdilazine concentration. The linear response was obtained in the range of 3.0 μM–1.0 mM with a detection limit of 0.1 μM. The proposed method was also applied for the quantitative determination of methdilazine in pharmaceuticals and biological samples.