Spectrophotometric Determination of Cefixime Trihydrate in Pharmaceutical Formulations Based on Ion-Pair Reaction with Bromophenol Blue

Cefixime trihydrate is a broad spectrum cephalosporin antibiotic, effective against gram-positive and gram-negative bacterial infections. Simple and rapid method has been developed for the determination of cefixime trihydrate in bulk and pharmaceutical formulations. This method was based on the formation of bluish-green ion-pair complex of cefixime trihydrate with bromophenol blue in dimethyl sulfoxide (DMSO)–acetonitrile medium. Different parameters were studied and optimized. A 2:1 complex was formed between the drug and reagent almost instantaneously at room temperature which has δmax of 610 nm. Under optimum conditions, calibration curve was found to be linear over the range of 10-130 µg mL-1. The method was subjected to analytical quality control. The limit of detection was found to be 1.08 µg mL-1. Recovery studies and interference studies were carried out. The proposed method was successfully applied to the determination of cefixime trihydrate in bulk and pharmaceutical formulations with high precision and accuracy.