Abstract: The present invention relates to a purification method of hydroxypropylmethyl cellulose phthalate, more particularly to a method of preparing high-purity hydroxypropylmethyl cellulose phthalate through a simple crushing process which comprises: increasing fluidity of reaction product mixture by adding fluidization solvent as a post-treatment process; and spraying it into water through a spray nozzle. As a result, formation of fine granular hydroxypropylmethyl cellulose phthalate particles prevents inter-particle coagulation during the a post-treatment process, and phthalic anhydride reactant, free phthalic acid and remaining acetic acid solvent can be removed effectively.

Abstract: The present invention relates to a preparation method of solvent-free water-dispersible hydroxypropyl methyl cellulose phthalate nanoparticle, and more particularly, to a preparation method of solvent-free water-dispersible hydroxypropyl methyl cellulose phthalate nanoparticle, which is environment-friendly and advantageous in disintegration and dissolution when used as an enteric coating material, which is prepared by obtaining suitable hydroxypropyl methyl cellulose phthalate (HPMCP) particle through aqueous emulsification process and regulating content of remaining electrolyte through ion exchange process.