Spectroscopic Determination of Mebendazole Using a 1,10 Phenanthroline–Iron Complex

Abstract

Simple, rapid, and sensitive spectroscopic methods have been proposed to determine the antifungal drug mebendazole. These methods adapted the reduction of ferric into ferrous in a 1,10 phenanthroline–iron complex in an acidic medium giving an orange–red ferroin complex. In the first method, the spectrofluorimetric assay was based on mebendazole quenching for the fluorescence of ferric–phenanthroline complex at pH 3.7. The fluorescence difference was quantitated at 409 nm after excitation at 254 nm. The second method involved the spectrophotometric measurement of the formed complex at 510 nm. A linear correlation was found over the concentrations 3.0–17.0 and 5.0–20.0 μg/mL respectively for methods I and II. The correlation coefficient (r) of the two methods is 0.9998. The two methods were successfully utilized for mebendazole determination in tablets. The mechanism of the reaction pathway is represented. Statistical comparison revealed no significant differences between the findings achieved by the proposed and comparison methods.