A pharmaceutical composition comprises: (i) a drug component comprising at least one indacaterol compound selected from indacaterol and the pharmaceutically acceptable derivatives thereof； and (ii) a propellant component comprising 1,1-difluoroethane (HFA-152a). Most preferably, the composition has less than 5 ppm of water. Preferably, the composition further comprises a glycopyrrolate (e.g. glycopyrronium bromide) and/or at least one corticosteroid (budesonide, mometasone, beclomethasone, fluticasone). Preferably, the composition further comprises a surfactant (polyvilylpyrrolidone, polyethylene glycol (PEG), oleic acid, lecithin). The composition may, or may not, contain ethanol as a polar excipient. The composition is suitable for use with a metered dose inhaler (MDI). Also claimed is a method for improving the stability of a pharmaceutical composition comprising a propellant and indacaterol through use of HFA-152a as the propellant.
