ABSTRACT
Three sensitive methods were developed for simultaneous determination of Ezetimibe [EZB] and Atorvastatin calcium [ATVC] in binary mixtures. First derivative [D[1]] spectrophotometry was employed for simultaneous determination of EZB [223.8 nm] and ATVC [233.0 nm] with a mean percentage recovery of 100.23 +/- 1.62 and 99.58 +/- 0.84, respectively. Linearity ranges were; 10.00-30.00 microg mL[-1] and 10.00-35.00 microg mL[-1], respectively. Isosbestic point [IS] spectrophotometry in conjunction with second derivative [D[2]] spectrophotometry was employed for analysis of the same mixture. Total concentration was determined at IS, 224.6 nm and 238.6 nm over a concentration range of 10.00-35.00 microg mL[-1] and 5.00-30.00 microg mL[-1] respectively. ATVC concentration was determined using D[2] at 313.0 nm [10.00-35.00 micro mL[-1] with a mean recovery percentage of 99.72 +/- 1.36, while EZB was determined mathematically at 224.6 nm [99.75 +/- 1.43] and 238.6 nm [99.80 +/- 0.95]. TLC-densitometry was employed for the determination of the same mixture; 0.10-0.60 [microg band[-1] for both drugs. Separation was carried out on silica gel plates using diethyl ether-ethyl acetate [7:3 v/v]. EZB and ATVC were resolved with R[f] values of 0.78 and 0.13. Determination was carried out at 254.0 nm with a mean percentage recovery of 99.77 +/- 1.30 and 99.86 +/- 0.97, respectively. Methods were validated according to ICH guidelines and successfully applied for analysis of bulk powder and pharmaceutical formulations. Results were statistically compared to a reported method and no significant difference was noticed regarding accuracy and precision