Abstract

Identification, isolation, characterization and quantification of a new impurity in Rosuvastatin calciumtablet dosage form

Author(s): Srinivasarao Koppala, Parsharamulu Rayam, V.Ranga Reddy, Jaya ShreeAnireddy

During the stability study of Rosuvastatin calcium (RSV) tablets, an unknown impurity was found at level of 0.8% by newly developed reverse phase HPLCmethod. The unknown impurity was identified by liquid chromatography –tandem mass spectrometry using electrospray ionization source and Q-trap mass analyzer (LC–ESI–QT/MS/MS). The drug product was subjected to stress to enhance the level of this impurity. The unknown was isolated by preparative liquid chromatography and characterized using the LC-MS, HRMS, NMR and IR spectral studies. Based on the spectroscopic data, the impurity was characterized as (3R,5S,E)-7-(4-(4- fluorophenyl)-6-isopropyl-2-(N-methylmethysulfonamido)pyrimidin-5- yl ) -3 ,5 -d ihyd r o xy-N-me thyl -N- ( (2S,3R,4R, 5R) -2 ,3 ,4 ,5 ,6 - pentahydroxyhexyl)hept-6-enamide (Imp-1). It is a novel impurity and not reported elsewhere. The newly developed method was validated as per ICH guidelines to demonstrate specificity, sensitivity, linearity, precision, accuracy and the stability-indicating nature.