Patent ID: 7348031
Filing Date: 2008-03-25
Classification: A61P,B01J

Abstract:
1. A process for the preparation of dispersible colloidal systems in the form of nanocapsules of mean diameter less than 600 nm, and having a wall comprising a polymer obtained by the polycondensation of a monomer α and a monomer β, and a core comprising a substance B, wherein monomer α is selected from the group consisting of acid dichlorides and diisocyanates, monomer β is selected from the group consisting of diamines, triamines and glycols, and substance B is an oil, comprising the steps of: (1) preparing a first liquid mixture comprising: (2) preparing a second liquid mixture comprising: wherein the solvent or solvent mixture is miscible in all proportions with the non-solvent or non-solvent mixture, and monomer β is present in a concentration which is at least a 5-fold excess, in terms of the number of moles, relative to the concentration of the monomer α; (3) adding the first mixture to the second mixture, with moderate agitation, to give a colloidal suspension of nanocapsules, and maintaining agitation until completion of polymerization; and (4) optionally, removing all or part of the solvent or solvent mixture and non-solvent or non-solvent mixture to give a colloidal suspension having the desired concentration of nanocapsules.