Spectrophotometric determination of bifonazole in pharmaceutical formulations using bromphenol blue

Abstract

A sensitive spectrophotometric method for the determination of bifonazole is described. Bifonazole was treated with bromphenol blue (BPB) in the presence of citrate buffer (pH 2.5; μ = 0.23). The formed ion-pair complex was extracted with chloroform. By using spectrophotometric measurements, Job's and Bent-French's methods, it was found that bifonazole and BPB formed an ion-pair complex with the absorption maximum at 414 nm (molecular ratio of bifonazole BPB = 1:2) and molar absorptivity 2.23 x 104 L mol-1 cm-1. Beer's law was obeyed up to 2.5 μg ml-1. The proposed method was applied for determination of bifonazole in pharmaceutical formulations. Statistical analysis of the results obtained showed that the proposed method has good reproducibility and precision.