Spectrofluorimetric Determination Of Mebendazole Lab Report

Enhanced spectrofluorimetric determination of Mebendazole, a benzimidazole anthelmintic drug, through complex formation with Lanthanum (III), in pharmaceutical preparations and spiked human plasma

Abstract
The article concerned with the development of simple, sensitive, rapid and specific spectrofluorimetric procedure for determination of mebendazole. The cited drug was reacted with lanthanum (III) ions to produce highly fluorescent stable complex measured at 340 nm after excitation at 295 nm. Different types of surfactant were tried to enhance the fluorescence of the formed complex but neither of them was effective. The influence of experimental factors on the relative fluorescence intensity of the resulting complexes were studied and optimized.
This interaction was employ in the development of a spectroflourimetric method for the analysis of samples containing this drug. The developed method has the advantage over the previously reported methods on being more sensitive, simple, less time consuming and having low detection limits. Moreover, the developed method utilize an inexpensive reagent and relatively low price instrument which is commonly available in most quality control
The investigated factors included pH, buffer volume, type, concentration of La3+, surfactants type, diluting solvents and reaction time. The influence of pH on the fluorescence intensity of the reaction product was studied using phosphate buffer solution having pH in the range of 4.0 – 8.0. The examined buffer solutions were: acetate, borate, phosphate and Toerell & Stenhagen. The general analytical procedure was performed using different volumes (0.2– 2.0 mL) of phosphate buffer (pH 5.5). The influence of the concentration of La3+ was studied using increasing volumes of a 5.1×10-4 M solution in the range of 0.05 – 2.0 mL of the reagent. The tested diluting solvents included water, dimethyl sulfoxide, acetonitrile, dioxan, ethanol, methanol, and 2-propanol. After mixing the studied drug solution with all reagents, the reaction mixture was allowed to stand at room temperature for different time interval and the fluorescence intensity was measured. Different surfactants were added to the reaction cocktail. These included; an anionic surfactant (sodium dodecyl sulfate, SDS), a cationic surfactant (cetyl pyridinum chloride, CPC) and non-ionic surfactant (Tween-80, Tween-20) and polyethylene glycol, PEG.
2.10. Determination of the reaction stoichiometry
Job’s method of continuous variation (25) was used to investigate the molar ratios of the formed metal complex.