Lurasidone Impurity : (3aR,4S,7R,7aS)-2-{[1R,2R]-2-[4-(1,2-benzisothiazol-3-yl)-piperazin-1-yl-methyl]-cyclohexyl methyl}hexhydro-4,7-methano-2H-isoindole-1,3-dione (Transdiene Lurasidone).