The present invention provides dimethyl sulphoxide solvate of 4-(4-{3-[4-chloro-3 -(trifluoromethyl)phenyl]ureido}phenoxy)-N2-methylpyridine-2-carboxamide, process for its preparation, pharmaceutical composition comprising it and its use for the treatment of cancer. The present invention also provides a novel HPLC method for the identification, quantification and isolation of related substances of sorafenib.