Validated spectrophotometric methods for the determination of bifonazole in pharmaceuticals by charge transfer complexation

Abstract

Two simple and selective visible spectrophotometric methods were developed for assay of bifonazole in pure drug and in its pharmaceutical formulation. The developed methods were based on the charge transfer complexation reaction of bifonazole with 2,5-dichloro-3,6-dihydroxy-1,4-benzoquinone (CAA) for method A and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) for method B, resulting in the formation of colored complex. The colored reaction products were quantitated spectrophotometrically at 517 nm and 457 nm for bifonazole-CAA and bifonazole-DDQ complexes, respectively. The complexes obeyed Beer’s law in the concentration range of 50.00–400.00 and 5.00–50.00 lg mL1 with molar absorptivities at 0.0956 · 104 and 0.6953 · 104 L mol1 cm1 for method A and method B, respectively. The proposed procedures were successfully applied for the quantitative determination of bifonazole in its pharmaceutical formulation. The solid charge transfer complexes of bifonazole with each of the p-acceptor reagent were also synthesized and characterized by FT-IR spectroscopy.