Atorvastatin EP Impurity C

Chemical Name: (3R,5R)-7-[2,3-bis(4-fluorophenyl)-4-(phenylcarbamoyl)-5-(propan-2-yl)-1H-pyrrol-1-yl]-3,5-dihydroxyheptanoic acid (as per EP); (3R,5R)-7-[2,3-Bis(4-fluorophenyl)-5-isopropyl-4-(phenylcarbamoyl)-1H-pyrrol-1-yl]-3,5-dihydroxyheptanoic acid (as per USP)