Patent ID: 8613953

Claim:
A method for obtaining solid micro- or nanoparticles which comprises the steps of: a) preparing in a closed container a mixture that includes an organic solvent or a mixture of organic solvents, a solid compound C and water, where in step a) there is at least one liquid phase and one solid phase, b) adding a fluid B to said mixture prepared in step a) so that the container reaches a first pressure P 1 , allowing said addition of fluid B at said first pressure, P 1 , to prepare a microemulsion of an organic phase saturated with water, where there is no solid phase in step b) and where at said first pressure, P 1 , a predetermined supersaturation value, β, of the solid compound C is less than or equal to 1, wherein said fluid B is a fluid which at atmospheric pressure and room temperature is a gas and which at said first pressure, P 1 , greater than atmospheric pressure, is miscible with the organic solvent, and immiscible or partially miscible with water, and is not a supercritical fluid at any stage, c) varying said first pressure, P 1 , to a second pressure, P 2 , where said variation in pressure does not equal zero, and where at said second pressure, P 2 , said water has an anti-solvent effect which causes precipitation of solid micro- or nanoparticles of compound C with homogenous structure; where in step c) there is at least one liquid phase and one solid phase; and, optionally; d) collecting at said second pressure, P2, said solid micro- or nanoparticles by conventional methods, wherein said solid micro- or nanoparticles have an aspect ratio value close to unity (1).