(16β)-17,21-Dihydroxy-16β-methyl-pregna-1,4,9(11)-triene-3,20-dione (Betamethasone EP Impurity C) is used in biological studies to perform preclinical characterization of VBP15, a novel anti-inflammatory delta 9,11 steroid. This compound is also used in analytical studies to determine the stability from reversed-phase high performance liquid chromatography (RP-HPLC) to separate low levels of dexamethasone and other related compounds from betametasone, which is an active pharmaceutical ingredient.