16ฮฒ-Methyl-3,20-dioxopregna-1,4-diene-17,21-diyl dipropanoate,2-oxo-2-((8R,9S,10R,13S,14S,16S,17R)-10,13,16-trimethyl-3-oxo-17-(propionyloxy)-6,7,8,9,10,11,12,13,14,15,16,17-dodecahydro-3H-cyclopenta[a]phenanthren-17-yl)ethyl propionate,Beclomethasone Impurity