(7R,8R,9S,13S,14S,17S)-4-bromo-7-(9-bromononyl)-3-hydroxy-13-methyl-7,8,9,11,12,13,14,15,16,17-decahydro-6H-cyclopenta[a]phenanthren-17-yl acetate,(7R,8R,9S,13S,14S,17S)-4-bromo-7-(9-bromononyl)-3-hydroxy-13-methyl-7,8,9,11,12,13,14,15,16,17-decahydro-6H-cyclopenta[a]phenanthren-17-yl acetate,Fulvestrant Impurity