Preparation process for disperse colloidal systems from a substance in the shape of nanoparticles

The method is characterized according to the invention in that:(1) a liquid phase is prepared constituted essentially by a solution of the substance in a solvent or in a mixture of solvents, and can be supplemented with one or more surfactants,(2) a second liquid phase is prepared constituted essentially by a non-solvent or a mixture of non-solvents of the substance and may be supplemented with one or more surfactants, the non-solvent or the mixture of non-solvents the substance being miscible in all proportions with the solvent or mixture of solvents of the substance,(3) is added, with moderate stirring, one of the liquid phases obtained under (1) or (2) to the other, so as to obtain a colloidal suspension of nanoparticles of the substance, and (4) if the is desired, removal of all or part of the solvent or solvent mixture of the substance and the non-solvent or mixture of non-solvents of the substance, so as to obtanie a colloidal suspension of desired concentration of nanoparticles or to obtain a powder of nanoparticles. Applications: chemistry, biochemistry, pharmacy, medicine.