Hydrocortisone EP Impurity O; (11β)-11,17,19,21-Tetrahydroxypregn-4-ene-3,20-dione; Hydrocortisone impurity O (EP); (8S,9S,10S,11S,13S,14S,17R)-11,17-dihydroxy-17-(2-hydroxyacetyl)-10-(hydroxymethyl)-13-methyl-2,6,7,8,9,11,12,14,15,16-decahydro-1H-cyclopenta[a]phenanthren-3-one; 19-Hydroxyhydrocortisone; Hydrocortisone Imp. O (EP)