8 Fluticasone propionate, the active component of FLONASE Nasal Spray, is a synthetic 9 corticosteroid having the chemical name S-(fluoromethyl)6α,9-difluoro-11β-17-dihydroxy-16α-10 methyl-3-oxoandrosta-1,4-diene-17β-carbothioate, 17-propionate and the following chemical 11 structure: 12 13 14