Spectrophotometric and High Performance Liquid Chromatographic Determination of Cefpodoxime Proxetil and Azithromycin Dihydrate in Pharmaceutical formulation

Introduction: UV spectrophotometric methods and High performance liquid chromatographic method were developed for the determination of the Cefpodoxime Proxetil and Azithromycin Dihydrate in tablet form. Methods: In UV Simultaneous equation method and Absorbance ratio method were used. The wavelength of maximum absorbance 232.40 nm for Cefpodoxime Proxetil and 218 nm for Azithromycin Dihydrate are used in simultaneous equation method and 220.60 nm (isoabsorptive point) and 232.40 nm (λ max of Cefpodoxime Proxetil) are used for absorbance ratio method. A simple liquid chromatographic assay has been developed for the determination of Cefpodoxime Proxetil and Azithromycin Dihhydrate. A C 18 (150×4.6 mm, 5 μm) column was used with a mobile phase consisting of Acetonitrile: Methanol: Phosphate buffer (40:40:20 v/v) at a flow rate of 1.0 ml min -1 . Quantitation of both drugs was achieved by using UV detector at 235 nm. Results : Calibration curves were linear in the range of 8-40 μg/ ml for Cefpodoxime Proxetil and 10-50 μg/ml for Azithromycin Dihydrate in absorbance ratio method. Accuracy for both the drugs was in the range of 98-101%. The retention time for Cefpodoxime Proxetil and Azithromycin Dihydrate was found to be 6.14 and 2.95 respectively. Beer’s law was obeyed in a concentration range of 20-100 μg/ml for Cefpodoxine Proxetil and 25- 150 μg/ml for Azithromycin Dihydrate and the regression line equation was derived with a correlation coefficient of 0.9984 and 0.9978 for Cefpodoxime Proxetil and Azithromycin Dihydrate respectively. The method was validated according to ICH guidelines for various parameters like accuracy, precision, specificity, linearity, robustness, LOD and LOQ. Discussion: The proposed procedures were successfully applied to the determination of Cefpodoxine Proxetil and Azithromycin Dihydrate in tablet form, with high percentage of recovery, good accuracy and precision. Key words: Cefpodoxime Proxetil, Azithromycin Dihydrate, Simultaneous equation method, Absorbance ratio method, HPLC, Tablets.