Simultaneous Determination of Atorvastatin Calcium and Telmisartan in Tablet Dosage Form by Spectrophotometry

Three accurate, precise, sensitive and economical procedures for simultaneous estimation of Atorvastatin Calcium and Telmisartan in tablet dosage form have been developed. The methods employed were absorbance correction method (I), first order derivative spectroscopic method (II) and duel wavelength method (III). The first method employs wavelength 328 nm for direct estimation of Telmisartan where Atorvastatin Calcium shows nil absorbance. Estimation of Atorvastatin Calcium is carried out after correction for absorbance of Telmisartan at 241 nm. The second method is based on first order derivative spectroscopy. Wavelengths 297 nm and 241.8 nm were selected for the estimation of the Atorvastatin Calcium and Telmisartan, respectively. In the third method, Atorvastatin Calcium was determined by plotting the difference in absorbance at 258 and 291 nm (difference is zero for Telmisartan) against the concentration of Atorvastatin Calcium. Similarly for the determination of Telmisartan, the difference in absorbance at 225 and 252 nm (difference is zero for atorvastatin calcium) was plotted against the concentration of Telmisartan. Both the drugs obey Beer’s law in the concentration range 5-30 μg/ml. The results of analysis have been validated statistically and by recovery studies.