The invention provides three polymorphic forms of crystalline levosalbutamol sulphate designated herein as Forms I, II and III. Crystalline levosalbutamol sulphate Form I is characterised by a powder XRD pattern with peaks at 10.8,11.9, 13.0, 18.3,28.5 ± 0.2 degrees 2 theta. Crystalline levosalbutamol sulphate Form II is characterised by a powder XRD pattern with peaks at 8.7, 9.6,15.2, 15.7, 19.1, 27.2, 30.7 ± 0.2 degrees 2 theta. Crystalline levosalbutamol sulphate Form III is characterised by a powder XRD pattern with peaks at 5.5, 6.9, 7.3, 18.7 ± 0.2 degrees 2 theta. Processes for making the new polymorphic forms and pharmaceutical compositions comprising them are also provided. A pharmaceutical composition comprises a therapeutically effective isomer of salbutamol or a salt, solvate, ester, derivative or polymorph thereof, a glucocorticoid and a pharmaceutically acceptable carrier or excipient and optionally one or more other therapeutic agents. Preferably the composition is an aerosol formulation comprising the drugs, a propellant and optionally one or more other ingredients, such as a surfactant, cosolvent, or bulking agent. Alternatively, DPI or inhalation suspensions may be used.