58ESTIMATION OF SIMVASTATIN AND EZETIMIBE BY USING HPTLC METHODA high-performance thin-layer chromatographic method has been developed and validated for the estimation of Simvastatin and ezetimibe simultaneously in combined dosage forms. The stationary phase used was pre-coated silica gel 60F 254. The mobile phase used was a mixture of Benzene: methanol: Acetone: Triethylamine (7.2:1:0.4 v/v/v/v). The detection of spots was carried out at 266 nm. The method was validated in terms of linearity, accuracy, precision and specificity. The calibration curve was found to be linear between 0.8 and 4.0 µg/spot for Simvastatin and 0.1 and 1.0 µg/spot for ezetimibe. The limit of detection and the limit of quantification for Simvastatin were found to be 160 ng/spot and 560 ng/spot respectively, and for ezetimibe, 30 ng/spot and 80 ng/spot respectively. The proposed method can be successfully used to determine the drug content of marketed formulation.bedadurgaprasad@gmail.comResearch312012Simvastatin,Ezetimibe, High-Performance Thin-Layer ChromatographyB. Durga Prasad,V. Girija Sastry,D. Prabhakar,M. Ram Mohan,A. Vara PrasadDepartment of Organic & Analytical Research Laboratory, Trinity College of Pharmaceutical Sciences, Peddapally, Karimnagar (dist)-505172. A.P, India.,Department of Organic & Analytical Research Laboratory, Trinity College of Pharmaceutical Sciences, Peddapally, Karimnagar (dist)-505172. A.P, India.,Department of Pharmaceutical Chemistry, AU College of Pharmacy, Andhra University, Vishkapatnam (Dist)-530003, A.P, India,Department of Analytical Chemistry, Talla padmavathi College of Pharmacy, Warngal (Dist)-506002. A.P, India, Department of Analytical Chemistry, Sri Balaji College of Pharmacy, Choppadandi, Karimnagar (Dist) -505415. A.P, India.