US Patent 7794754 Methods for fine powder formation

Improved methods for forming fine particles of a material have been developed, wherein the method steps include dissolving the material in a solvent to form a dilute solution, immobilizing the dilution solution, and then removing the solvent to yield particles of the material. Methods of immobilizing the dilute solution include freezing, gelation, and chelation. In a preferred embodiment, the immobilized solvent is removed by lyophilization, i.e. reducing the ambient pressure while avoiding application of sufficient heat to power a phase transition. Essentially any material and solvent for the material can be used in the methods described herein. Proteins and peptides in an aqueous solvent are the preferred systems.