Patent ID: 7138141

Claim:
A method for preparing dispersible dry powders of biological macromolecules, said method comprising: providing an evaporable liquid medium containing a macromolecule selected from the group consisting of proteins, polypetides, oligopeptides, nucleic acids, and polysaccharides, wherein the concentration of total solids in the liquid medium is less than 10% by weight; atomizing the liquid medium consisiting of said marcomolecule to form droplets by flowing the liquid medium and an atomization gas stream at a gas:liquid mass flow ratio above 5 under conditions selected to form droplets having an average size of between 5 μm and 11 μm; and drying the droplets in a single drying step, in a heated gas stream, wherein the heated gas stream has an outlet temperature of at least 70° C., to produce particles having a rugosity of at least 2.0 as measured by air permeametry, wherein 90% of the mass of the powder comprises particles having a diameter in the range of between about 0.1 microns and about 7 microns, and wherein the particles have a final moisture content of below 5% by weight.