Patent ID: 6468506
Filing Date: 2002-10-22
Classification: A61K,A61P,C08J,C08L

Abstract:
A process for the production of gaseous microparticles for ultrasonic diagnosis, whose wall material is built up from polyesters of &agr;-, &bgr;-, or &ggr;-hydroxycarboxylic acids, comprising:dissolving the polyester(s) and optionally a surface-active substance in an organic solvent or solvent mixture to obtain a polyester solution, of which at least one solvent is readily water-miscible, dispersing a liquid perfluorinated compound which is not a solvent for the polymer in the polyester solution to obtain a dispersion and then dispersing the dispersion in water that contains a surface-active substance using a stirring mechanism, removing the solvent by pumping in gas and applying a vacuum to obtain a suspension, and mixing the suspension with a suitable pharmaceutically acceptable cryoprotector and freeze-drying to yield gaseous microparticles.