An inhalable pharmaceutical solution aerosol comprising beclometasone dipropionate, ethanol and a propellant selected from 1,1,1,2-tetrafluoroethane, 1,1,1,2,3,3,3-heptafluoropropane and a mixture thereof, wherein the aerosol has a droplet size having a mass median aerodynamic diameter of 0.5-2.0 &mu；m, for maintaining lung function above 60% of baseline FEV1, or reducing the occurrences of lung function falling below 60% of baseline FEV1.
