Patent ID: 9011888
Filing Date: 2015-04-21
Classification: A61K,A61Q,C01P,C09C

Abstract:
1. A process for producing organic-inorganic composite particles comprising inorganic oxide particles each of which has a cationic charge on the particle surface and polymer gel molecules which are derived from a natural substance, have an anionic functional group and one or more hydroxyl groups in a molecule and further have water retention property due to shrinking and swelling property, said polymer gel molecules being electrostatically bonded to surfaces of the inorganic oxide particles, said process consisting of: (1) a step wherein a solvent capable of shrinking the polymer gel molecules is added to a solution containing the polymer gel molecules and they are stirred, (2) a step wherein the inorganic oxide particles are added to the solution obtained in the step (1) and they are stirred to electrostatically bond the polymer gel molecules to the surfaces of the inorganic oxide particles, (3) a step wherein a solvent capable of swelling the polymer gel molecules is added to the dispersion obtained in the step (2) and they are stirred to swell the polymer gel molecules having been electrostatically bonded to the surfaces of the inorganic oxide particles, (4) a step wherein the dispersion obtained in the step (3) is filtered to separate a solid component, and (5) a step wherein the solid component obtained in the step (4) is dried, wherein the polymer gel molecules are those of hyaluronic acid, the solvent added in step (1) is acetone, and the solvent added in step (3) is water.