Aerosol formulations comprising formoterol fumarate dihydrate, a propellant, ethanol and optionally a steroid, wherein the formoterol fumarate dihydrate has a water content of 4.8-4.28% by weight
A pharmaceutical aerosol formulation comprising formoterol fumarate di-hydrate in suspension, and a steroid in suspension, and a propellant, ethanol, and optionally a surfactant, wherein the formoterol fumarate di-hydrate has a water content of about 4.8 to 4.28% by weight.