Difference Spectrophotometric Method Development and Validation For Simultaneous Estimation of Rosuvastatin Calcium and Telmisartan in Bulk and Combined Dosage Form

Rosuvastatin calcium and Telmisartan combination is used in the treatment of coronary heart diseases. UV spectrophptometric and chromatographic methods were reported in the literature forthe estimation of Rosuvastatin calcium and Telmisartan. Therefore a simple and highly sensitive difference spectrometric method for the estimation of Rosuvastatin calcium and Telmisartan in bulk and in combined dosage form is described. The proposed method is based on the principle that both the drugs can exhibit two different forms in acidic and basic medium that differs in their absorption spectra in acidic and basic medium. In the difference spectrum, Rosuvastatin calcium showed maxima at 248nm and minima at 237.5nm and Telmisartan showed maxima at 309nm and minima at 286nm. Linearity range was observed in the concentration range of 20-60μg/ml for Rosuvastatin calcium and Telmisartan. Percentage purity and recovery study were in the limit of 98-102% and precision was less than 2 for both drugs. Limit of Detection for Rosuvastatin calicium and Telmisartan were found to be 0.0635μg/ml and 0.1693μg/ml respectively. Limit of Quantitatin for Rosuvastatin calcium and Telmisartan were found to be 0.1925 μg/ml and 0.5129μg/ml respectively. The proposed method can be successfully used for the analysis of pure drug and marketed formulation. The method is found to be precise, simple, accurate and can be applied for the routine estimation of Rosuvastatin calcium and Telmisartan.