Method for fabricating polymer-based controlled-release devices

Abstract

The present invention includes a method for producing an implantable polymer/drug matrix mass, comprising the steps of (1) forming a polymer solution/drug mixture comprising a polymer dissolved in an organic solvent and a suspended labile drug; (2) removing the solvent from the polymer solution/drug mixture, thereby forming a solid polymer/drug matrix; and (3) mechanically compressing the polymer/drug matrix, thereby forming an implantable polymer/drug matrix mass.

What is claimed is:  
     
         1 . A method for forming an implantable polymer/drug matrix mass wherein the drug is a protein, consisting essentially of the steps of: 
 a) forming a polymer solution/protein mixture comprising a polymer dissolved in an organic solvent and a suspended protein;    b) removing the solvent from the polymer solution/protein mixture, thereby forming a solid polymer/protein matrix; and    c) mechanically compressing the polymer/protein matrix, thereby forming an implantable polymer/protein matrix mass.    
     
     
         2 . The method of  claim 1  wherein the polymer is a bioerodable polymer.  
     
     
         3 . The method of  claim 1  wherein the solvent is removed from the polymer solution/protein mixture at a temperature below the freezing point of the polymer solution/protein mixture.  
     
     
         4 . The method of  claim 1  wherein the solvent is removed from the polymer solution/protein mixture by a method comprising the steps of: 
 (i) freezing the polymer solution/protein mixture, thereby forming a solid polymer solution/protein mixture; and  
 (ii) extracting the solvent from the solid polymer solution/protein mixture.  
 
     
     
         5 . The method of  claim 4  wherein the polymer solution/protein matrix is frozen by directing the polymer solution/protein mixture into a liquid nonsolvent, at a temperature below the freezing point of the polymer solution/protein mixture.  
     
     
         6 . The method of  claim 5  wherein the polymer solution/protein mixture is directed into the liquid nonsolvent by pouring, atomizing, spraying, extruding or dripping the polymer solution/protein mixture into the liquid nonsolvent.  
     
     
         7 . The method of  claim 4  wherein the polymer/protein matrix is frozen by directing the polymer solution/protein mixture onto a frozen nonsolvent bed in the presence of a liquified gas.  
     
     
         8 . The method of  claim 4  wherein the solvent is extracted from the polymer solution/protein mixture by contacting the solid polymer solution/protein mixture with a nonsolvent, thereby extracting the solvent into the nonsolvent.  
     
     
         9 . The method of  claim 4  wherein the solvent is extracted from the solid polymer solution/protein mixture by lyophilizing the solid polymer solution/protein mixture.  
     
     
         10 . The method of  claim 1  wherein the solvent is removed from the polymer solution/protein mixture by a method comprising the steps of: 
 (i) directing the polymer solution/protein mixture into a nonsolvent at a temperature suitable for precipitating the polymer/protein matrix, thereby forming a polymer/protein matrix-nonsolvent mixture; and  
 (ii) separating the nonsolvent and the polymer/protein matrix by filtering the polymer/protein matrix-nonsolvent mixture.  
 
     
     
         11 . An implantable polymer/protein matrix mass produced by the method of  claim 1 .  
     
     
         12 . The method of  claim 1  wherein the bioerodable polymer is selected from the group consisting of poly(lactic acid), poly(lactic acid-co-glycolic acid) copolymer, poly (caprolactone), polycarbonates, polyamides, polyanhydrides, poly(amino acid)s, poly(ortho ester)s, polyacetals, polycyanoacrylates and polyurethanes.