The present invention relates to methods for the preparation of an aerosol. More specifically the present invention provides methods for the preparation of an aerosol of immunoglobulin single variable domains wherein the amount of aggregate formation is significantly reduced. The invention further provides aerosols prepared by the methods of the invention, as well as compositions for use in the methods of the invention. The invention further relates to methods for the preparations of such compositions, to containers, kits and aerosol delivery systems comprising such compositions and to uses of the same.
