INDIRECT SPECTROPHOTOMETRIC DETERMINATION OF MEBENDAZOLE VIA OXIDATION-INDUCED DECOLORIZATION OF NEUTRAL RED DYE: APPLICATION TO PHARMACEUTICAL TABLETS AND HUMAN SERUM

The aim of this method is to develop a simple, accurate, sensitive, inexpensive, indirect spectrophotometric assay of mebendazole in pharmaceutical formulation (tablets) and pure form. The suggested technique relies on the oxidation of mebendazole by the addition of a known excess amount of calcium hypochlorite in an acidic medium at room temperature. Then unreacted calcium hypochlorite is reacted with neutral red dye in order to discolor its color. The absorbance was recorded at 525 nm; at concentrations between 2 and 20 µg/ml, a linear association was seen. The calculated molar absorptivity is 12520.42 L/mol.cm, and the Sandell sensitivity value is 0.0236 μg/cm².The limits of detection (LOD) and quantification (LOQ) were determined and found to be 0.089 µg/mL and 0.298 µg/mL, respectively. Absence of additive interference in the dose forms when the proposed method was successfully used to determine MBZ in dose and bulk medication form.