Propellant mixtures and medicament aerosols which contain them are described for micronising medicaments for pulmonary use. The propellant mixture is in a subcritical state and contains at least one component from a first class of propellant gasses and at least one component from a second class of propellant gasses. The first class includes propellant gasses with an evaporation enthalpy of 200 kJ/kg or less at 25 °C and a vapour pressure of 20 bars or more at 25 °C, and the second class includes propellant gasses with an evaporation enthalpy of 300 kJ/kg or more at 25 °C and a vapour pressure of 10 bars or less at 25 °C. By using this propellant mixture in a medicament aerosol, micronised medicaments are obtained in which approximately 80 % by weight of the generated particles have less than 8 νm diameter.