초록 ▼

Microspheres, optionally containing an ingredient to be dispensed through controlled release, are prepared by solvent evaporation of an oil-in-water emulsion formed from an organic solvent containing a polymer and a plasticizer and an aqueous solution containing one or more emulsifying agents. The m

Microspheres, optionally containing an ingredient to be dispensed through controlled release, are prepared by solvent evaporation of an oil-in-water emulsion formed from an organic solvent containing a polymer and a plasticizer and an aqueous solution containing one or more emulsifying agents. The microcapsules formed have a size of between about 3 and about 300 microns in diameter and are porous and spongy in structure as opposed to the hollow core, relatively solid surface structure of microspheres formed by solvent evaporation without utilizing a plasticizer. The microspheres can have a relatively high loading rate of an ingredient to be dispensed combined with a relatively low release rate and are useful for instance for agricultural chemicals, pharmaceuticals or medicines, cosmetics or fragrances.

대표청구항 ▼

[ What is claimed is:] [1.] A process for producing porous spongy microspheres characterized by an uneven porous surface and a porous internal structure resembling a sponge having a diameter between about 3 and about 300 microns comprising: (a) preparing an organic phase comprising a solution of a p

[ What is claimed is:] [1.] A process for producing porous spongy microspheres characterized by an uneven porous surface and a porous internal structure resembling a sponge having a diameter between about 3 and about 300 microns comprising: (a) preparing an organic phase comprising a solution of a polymer and a plasticizer selected from the group consisting of phthalate esters, phosphate esters, citrate, sebacate esters, glycerol, triacetin and acetylated monoglycerides, in an organic solvent; (b) preparing an aqueous phase comprising an aqueous solution of one or more emulsifying agents; (c) combining the organic and aqueous phases under emulsifying conditions to form an emulsion of the organic phase in the aqueous phase; and (d) evaporating the solvent to form said porous, spongy microspheres of uneven porous surface and a porous internal structure resembling a sponge.