Isolation, identification and characterization of degradation impurity of atorvastatin in fixed dose combination of atorvastatin and ezetimibe

Abstract

The objective of this study is to isolation and characterization of unknown degradation product of Atorvastatin calcium in combination formulation product with Ezetimibe by using modern techniques of separation and characterization. An unknown impurity is generating during a forced degradation study of Atorvastatin and Ezetimibe fixed-dose combination tablets. By using the gradient reversed-phase high-pressure liquid chromatographic method, unknown degradation impurity was detected and quantified in the range of 0.05% to 0.2% of Atorvastatin. The impurity was enriched by extreme oxidation degradation of Atorvastatin and isolated through preparative HPLC. The structure of the impurity was characterized by mass and NMR spectrum.