Title:  Preparation method for biodegradable polymeric microspheres using solvent extraction and preparation method for microspheres for treating local inflammation using the same

United States Patent:  6,149,944

Assignee:  Korea Institute of Science and Technology (Seoul, KR)

Filed:  August 2, 1999

PCT NO:  PCT/KR97/00055

102(e) Date:  August 2, 1999

PCT PUB. Date:  October 9, 1997

Foreign Application Priority Data:  Apr 01, 1996[KR] (96/9755)

A preparation method for biodegradable polymeric microspheres using a solvent extraction method for biodegradable polymeric microspheres for treating a local inflammation disease using the same which are capable of effectively curing ozena such as sinusitis and a middle ear infection. Since a non-solvent of polymer is added into an outer aqueous phase in advance, the solidification of the polymer is implemented in a short time which, in turn, improves encapsulation of the therapeutic agent used.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide an improved preparation method for biodegradable polymeric microspheres using a solvent extraction method and a preparation method for biodegradable polymeric microspheres for treating local inflammation using the same which overcome the aforementioned problems encountered in the conventional art.

It is another object of the present invention to provide an improved preparation method for biodegradable polymeric microspheres using a solvent extraction method and a preparation method for microspheres for treating local inflammation using the same which are capable of more effectively preventing a decrease of an encapsulation efficiency of an agent compared to the conventional solvent extraction method.

It is another object of the present invention to provide an improved preparation method for biodegradable polymeric microspheres using a solvent extraction method and preparation method for microspheres for treating local inflammation using the same which are basically directed to developing a continuously releasing therapeutic agent in order to cure a local inflammative disease.

It is another object of the present invention to provide an improved preparation method for biodegradable polymeric microspheres using a solvent extraction method and preparation method for microspheres for treating a local inflammation disease using the same which are capable of effectively curing ozena such as sinusitis and a middle ear inflammation.

The preparation method for biodegradable polymeric microspheres according to the present invention includes a step for first preparing a W/O type emulsion by mixing an inner aqueous phase and an organic phase comprising an organic solvent of polymer in which a biodegradable polymer is dissolved, and then well dispersing the resulting emulsion;

a step for preparing an outer aqueous phase wherein a non-solvent of the polymer is dissolved;

a step for adding the aforementioned W/O type emulsion into the outer aqueous phase to prepare a W/O/W type emulsion; and

a step for removing an organic solvent of polymer.

The preparation method for biodegradable polymeric microspheres for treating local inflammation disease according to the present invention includes a step for preparing a W/O type emulsion by mixing an inner aqueous phase containing water-soluble betalactam antibiotic agent and/or an inhibitor of betalactamase and an organic phase comprising an organic solvent of polymer in which a biodegradable polymer is dissolved, and then well dispersing the resulting emulsion;

a step for preparing an outer aqueous phase wherein a non-solvent of the polymer is dissolved;

a step for adding the aforementioned W/O type emulsion into the outer aqueous phase to prepare a W/O/W type emulsion; and

a step for removing an organic solvent of polymer.

Claim 1 of 2 Claims

What is claimed is:

1. A preparation method for a biodegradable polymeric microspheres for treating local inflammation disease, comprising:

a step for preparing a W/O emulsion by mixing an inner aqueous phase containing water-soluble betalactam antibiotic agent and/or an inhibitor of betalactamase and an organic phase comprising an organic solvent of polymer in which a biodegradable polymer is dissolved, well dispersing the resulting emulsion;

a step for preparing an outer aqueous phase wherein a non-solvent of the polymer is dissolved in an aqueous solution of distilled water containing a surface active agent;

a step for adding the aforementioned W/O emulsion into the said outer aqueous phase to prepare a W/O/W emulsion; and

a step for removing the organic solvent of the polymer.

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