Simultaneous Estimation Of Rosuvastatin Calcium And Ezetimibe In Their Combined Tablet Dosage Form By Absorbance Ratio Method

A simple, accurate, precise, and economical Q-absorbance ratio UV-spectrophotometric method was developed and validated for simultaneous estimating Rosuvastatin Calcium and Ezetimibe in combined tablet dosage form. The solvent used was a 1:1 t mixture of Isopropyl alcohol and distilled water. Two wavelengths 244nm (λmax of Rosuvastatin Calcium) and 240nm (Isoabsorptive point) were selected to estimate Rosuvastatin Calcium and Ezetimibe for the Q-Absorbance ratio method. The drug concentration was determined using the ratio of absorbance at the iso-absorptive point (λ1 = 240 nm) and the λmax of Rosuvastatin Calcium (λ2 = 244 nm). This method is linear for both drugs in the range of 5 to 25 μg/ml at λ1 (R2 = 0.998) and at λ2 (R2 = 0.997) for Rosuvastatin Calcium, and Ezetimibe in the range of 5 to 25 μg/ml for found at λ1 (R2 = 0.9992) and λ2 (R2 = 0.9993). The percentage recovery was 102.11 % of Rosuvastatin Calcium and 99.72 % of Ezetimibe by standard addition method. The LOD was found to be 1.126 μg/ml and 1.400 μg/ml for Rosuvastatin Calcium at λ1 and λ2 respectively. The LOD was found to be 0.713 μg/ml and 0.396 μg/ml for Ezetimibe at λ1 and λ2 respectively. The LOQ was found to be 3.412μg/ml and 4.240μg/ml for Rosuvastatin Calcium at λ1 and λ2 respectively. The LOQ was found to be 2.162μg/ml and 1.199μg/ml for Ezetimibe at λ1 and λ2 respectively. The method was precise as % RSD was found to be less than 2  in Repeatability and Interday for Rosuvastatin Calcium and Ezetimibe. The % assay of analyte drugs in the combined tablet dosage form was found to be 101.41% of Rosuvastatin Calcium and 99.24 % of Ezetimibe which showed good applicability of the developed method.