Formation of aqueous small droplet aerosols assisted by supercritical carbon dioxide

An aerosol with a high number density of particles with droplet sizes small er than 3 mu m in diameter is produced by rapidly expanding an emulsion com prised of an aqueous solution and supercritical fluid CO2 at pressures from 1071 to 5000 psi at 35 degrees to 100 degrees C, After dilution with air, fine droplet aerosols of aqueous pharmaceuticals, such as rhDNase, are suit able for pulmonary drug delivery. Dehydration of the aqueous droplets yield s fine-particle dry powders, potentially important in pharmaceutical proces sing and in the generation of fine particles of metal oxides by pyrolysis o f metal nitrates or acetates, Thin films of metals or metal oxides can be f ormed by directing an aerosol containing coating precursors onto heated sur faces.