Simultaneous Estimation of Olmesartan and Atorvastatin in Bulk and Fromulation by Using Uv Spectroscopy and Rp-hplc

Volume 1(2) March-April 2013 Page 244 SIMULTANEOUS ESTIMATION OF OLMESARTAN AND ATORVASTATIN IN BULK AND FROMULATION BY USING UV SPECTROSCOPY AND RP-HPLC Revanth Reddy B * , Aravind G Nimra college of pharmacy, Vijayawada *Corresponding author: E.mail: [email protected] ABSTRACT Simple, rapid and accurate UV Spectroscopic (Simultaneous Equation method and First order derivative method) and an isocratic RP – HPLC methods showed excellent sensitivity, reproducibility, accuracy, and repeatability. In simultaneous UV method, the overlaid spectra of mixture of Olmesartan medoxomil and Atorvastatin calcium were recorded. From the spectra, 256.5nm for Olmesartan medoxomil and 247nm for Atorvastatin calcium was selected as wavelength to construct simultaneous equation. The percentage label claim present in tablet formulation was found to be 100.187 ± 1.074% and 101.511 ± 1.841% for Olmesartan medoxomil and Atorvastatin calcium respectively. In second method, the same spectrums were derivatised and 247 nm selected for detection of Olmesartan medoxomil where Atorvastatin calcium shows zero crossing and also 310 nm selected for detection of Atorvastatin calcium where Olmesartan medoxomil shows zero crossing. The percentage label claim present in formulation was found to be 100.254 ± 1.6281 and 99.968 ± 0.000054 for Olmesartan medoxomil and Atorvastatin calcium respectively. In RP-HPLC method, mobile phase used is acetonitrile: phosphate buffer pH 3.0 (60:40 V/V) with flow rate of 0.9 mL per min, the retention time of Olmesartan medoxomil and Atorvastatin calcium were found to be 3.19 and 4.63, respectively at 252 nm. The percentage purity was found to be 101.12 ± 0.8107 and 101.83 ± 0.4684 for Olmesartan medoxomil and Atorvastatin calcium, respectively. The low % RSD values for recovery indicated that the method was found to be accurate.