Methylprednisolone EP Impurity H Catalogue G112648 CAS 18462-27-6 M.W 374.47 M.F C22H30O5 Specifications FAQs (6R,8S,9S,10R,11S,13S,14S,17R)-11,17-dihydroxy-17-(2-hydroxyacetyl)-6,10,13-trimethyl-6,7,8,9,10,11,12,13,14,15,16,17-dodecahydro-3H-cyclopenta[a]phenanthren-3-one