Abstract: A nanoparticulate system prepared by: 1) preparing a liquid phase essentially consisting of a solution of cyclodextrin modified by acyl groups in an organic solvent or solvent mixture, an active molecule being optionally added thereto; 2) preparing a second liquid phase essentially consisting of water or an aqueous mixture optionally containing one or more surfactants, and optionally having an active molecule added thereto; and 3) gently stirring one of the liquid phases resulting from 1) or 2) into the other in order to obtain, almost instantaneously, a colloidal solution of modified cyclodextrin nanospheres. If required, all or part of the solvent and all or part of the water may be removed. The system may be used as a carrier for pharmaceuticals, cosmetics, chemicals, etc.