ABSORBANCE RATIO SPECTROPHOTOMETRIC METHOD FOR THE SIMULTANEOUS ESTIMATION OF DEXAMETHASONE SODIUM PHOSPHATE AND ATROPINE SULPHATE IN EYE DROP
A simple, sensitive, rapid, accurate, precise Absorbance Ratio Method was developed for the simultaneous determination of Dexamethasone Sodium Phosphate and Atropine Sulphate in combined dosage form. Absorbance ratio method uses the ratio of absorbance at two selected wavelengths, one which is an iso absorptive point and other being the Î»max of one of the two components. Dexamethasone Sodium Phosphate and Atropine Sulphate show an iso absorptive point at 228.60 nm in methanol. The second wavelength used is 239.60 nm, which is the Î»max of Dexamethasone Sodium Phosphate in methanol. The linearity was obtained in the concentration range of 20-60 Î¼g/ml for Atropine Sulphate (r2=0.9991) and 2-6 Î¼g/ml for Dexamethasone Sodium Phosphate(r2=0.9994).LOD is 0.063 and 3.01 Î¼g/ml for Dexamethasone Sodium Phosphate and Atropine Sulphate respectively.LOQ is 0.19 and 9.12 Î¼g/ml for Dexamethasone Sodium Phosphate and Atropine Sulphate respectively. The concentrations of the drugs were determined by using ratio of absorbance at iso absorptive point and at the Î»max of Dexamethasone Sodium Phosphate. The method was successfully applied to pharmaceutical dosage form because no interference from the excipients was found. The results of analysis have been validated.