Patent ID: 6120805
Filing Date: 2000-09-19
Classification: A61K

Abstract:
A process for preparing a composition of biocompatible microspheres, the process comprising the following steps:(a) preparing a first solution comprising (i) a biodegradable and biocompatible polymer, the polymer selected from the group consisting of homopolymers of lactic acid, homopolymers of glycolic acid, copolymers of lactic acid and glycolic acid, polymers of polyhydroxybutyric acid, polylactones of fatty acid containing more than twelve carbon atoms, polyorthoesters, fatty acid polyhydroxyesters having more than twelve carbon atoms, and polyanhydrides, and (ii) an active principal selected from the group consisting of anti-inflammatory agents, antibacterial agents, anticancer agents, agents having an action on the heart, and diagnostic agents, in a water-immiscible solvent, the solvent being more volatile than water;(b) preparing a second solution in water comprising a biodegradable and biocompatible surface-active agent selected from the group consisting of serum albumin, fetuin, orosmuccoid, glycoproteins, immunoglobulins, gelatin, collagen, bile salts, phospholipid, and lipopolysaccharide;(c) mixing the first solution with the second solution to form an aqueous emulsion by using a high pressure homogenizer capable of producing pressure of about 10.sup.5 to about 11.times.10.sup.5 Pa; and(d) evaporating the water-immiscible solvent;wherein the aqueous emulsion contains less than about 10 ppm of heavy metals, the microspheres have a particle diameter of between about 0.05 micron and about 1 micron, the active principal is present as about 0.05 to about 20% by weight of the composition, the biodegradable and biocompatible polymer is present as about 0.1 to about 40% by weight of the composition, the biodegradable and biocompatible surface-active agent is present as about 0.2 to about 20% by weight of the composition, and water is present as about 20 to about 99.65% by weight of the composition.