Effect of Solvents on Spectrophotometric Determination of Cefpodoxime Proxetil in Pure and Tablet Dosage Form through Ion-Pair Complex Formation Using Bromophenol Blue

A simple, direct and accurate spectrophotometric method has been developed for the determination of cefpodoxime proxetil (CEFP) in pure and tablet dosage form. The method involves the formation of yellow ion-pair complexes between the cited drug and bromophenol blue (BPB) using some solvents. Dichloroethane and chloroform were the best. The absorbance is measured at λ_max 412 and 422 nm in dichloroethane and chloroform, respectively. Variables were studied in order to optimize the reaction conditions. Molar absorptivity (ε) for [CEFP]:[BPB] and [CEFP]:[BPB]2 complexes were selected. Beer's law was obeyed in the concentration range of 0.2788-44.608 μg.mL-1 and 0.5576-44.608 μg.mL^-1 in presence of 1x10^-3 mol.L^-1 of BPB with good correlation coefficient (R²=0.9996 and R²=0.9998) in dichloroethane and chloroform, respectively. The relative standard deviation did not exceed 4.3%. The proposed method was validated for specificity, linearity, precision and accuracy, repeatability, sensitivity (LOD and LOQ) and robustness. The developed method is applicable for the determination of CEFP in pure and different dosage forms with average recovery 98.8% to 101.1%, and 98.6% to 101.2% in dichloroethane and chloroform, respectively, and the results are in good agreement with those obtained by the RP-HPLC reference method.