The active component of QVAR (beclomethasone dipropionate hfa) 40 mcg Inhalation Aerosol and QVAR 80 mcg Inhalation Aerosol is beclomethasone dipropionate, USP, an anti-inflammatory corticosteroid having the chemical name 9-chloro-11?,17,21-trihydroxy-16??­methylpregna-1,4-diene-3, 20-dione 17,21-dipropionate. Beclomethasone dipropionate (BDP) is a diester of beclomethasone, a synthetic corticosteroid chemically related to dexamethasone. Beclomethasone differs from dexamethasone in having a chlorine at the 9-alpha carbon in place of a fluorine, and in having a 16 beta-methyl group instead of a 16 alpha-methyl group. Beclomethasone dipropionate is a white to creamy white, odorless powder with a molecular formula of C28H37ClO7 and a molecular weight of 521.1. Its chemical structure is: