Patent ID: 7887846
Filing Date: 2011-02-15
Classification: A61K,A61P,Y10S

Abstract:
1. A process for making a swellable and degradable microsphere preparation comprising the steps of: a) forming a first solution having a pH of at least 3 or about 3 comprising: b) forming a second solution comprising at least one substantially chlorinated hydrocarbon of less than 6 carbon units, c) forming a first suspension with agitation comprising the first and second solutions at a temperature below the activation temperature of the azo initiator of (a); d) increasing the temperature of the first suspension to a temperature at which the water soluble azo initiator is activated; e) agitating the first suspension until it forms a second suspension comprising a gelatinous precipitate suspended in an organic liquid phase, wherein microspheres are formed; f) allowing the second suspension to cool to a temperature that is at about 30° C. or below 30° C. while agitating the second suspension; g) washing the second suspension at least once with a dehydrating solvent wherein water is removed from the microspheres, producing a microsphere slurry comprising washed microspheres; h) recovering the washed microspheres from the microsphere slurry; and i) heating the washed microspheres to a temperature above 25° C. for a time sufficient to substantially dry the washed microspheres to form the swellable and degradable microsphere preparation; wherein the process is carried out in absence of a crosslinking agent.