Loading and release of water-insoluble drugs

Abstract

A medical device, polymer composition, and method for delivering substantially water-insoluble drugs to tissue at desired locations within the body. At least a portion of the exterior surface of the medical device is provided with a polymer coating. Incorporated in the polymer coating is a solution of at least one substantially water-insoluble drug in a volatile organic solvent. The medical device is positioned to a desired target location within the body, whereupon the drug diffuses out of the polymer coating.

1 . A catheter for delivering a substantially water-insoluble drug at a desired location within a body, comprising: 
 a catheter for insertion into a body lumen, having a shaft and an expandable balloon at a distal end of the shaft,    said balloon having a polymer coating on at least a portion of an exterior surface,    said polymer coating having a thickness of between about 0.2 and 50 microns, said polymer coating containing at least one substantially water-insoluble drug.    
     
     
         2 . The catheter of  claim 1 , wherein said polymer coating has a thickness of between about 1 and 10 microns.  
     
     
         3 . The catheter of  claim 1 , wherein said polymer coating has a thickness of between about 2 and 5 microns.  
     
     
         4 . The catheter of  claim 1 , wherein said polymer coating has a thickness of between about 0.2 and 0.3 microns.  
     
     
         5 . The catheter of  claim 1 , wherein said polymer coating has a thickness greater than about 10 microns.  
     
     
         6 . The catheter of  claim 1 , wherein said polymer coating is layered.  
     
     
         7 . The catheter of  claim 1 , wherein said polymer is hydrophillic.  
     
     
         8 . The catheter of  claim 1 , wherein said polymer is hydrophobic.  
     
     
         9 . The catheter of  claim 1 , wherein said polymer is a polyvinyl aromatic.  
     
     
         10 . The catheter of  claim 1 , wherein said at least one substantially water-insoluble drug is paclitaxel.  
     
     
         11 . The catheter of  claim 1 , wherein said at least one water-insoluble drug comprises a combination of paclitaxel and an agent selected from the group consisting of anti-coagulants, anti-mitotics, anti-thrombogenics, thrombolytics, anti-inflammatory agents, nitric oxide containing polymers, or vascular cell promoters.  
     
     
         12 . The catheter of  claim 1 , wherein said at least one water-insoluble drug is released from said stent over a time frame effective to inhibit proliferative disease when said catheter is positioned at a site of injury to thereby prevent or inhibit undesired cellular proliferation.  
     
     
         13 . A method of preparing a balloon catheter having a balloon with a substantially water-insoluble drug coating comprising: 
 dissolving at least one substantially water-insoluble drug in an organic solvent to create a drug solution; and    applying said drug solution to at least a portion of an exterior surface of the balloon.    
     
     
         14 . The method of  claim 13 , further comprising the step of coating at least a portion of the exterior surface of said balloon with a polymer to form a polymer coating prior to applying said drug solution to at least a portion of the exterior surface of said balloon.  
     
     
         15 . The method of  claim 14 , further comprising the step of evaporating said organic solvent from said polymer coating after applying said drug solution.  
     
     
         16 . The method of  claim 15 , wherein the step of evaporating the organic solvent from said polymer coating is performed in a vacuum oven.  
     
     
         17 . The method of  claim 13 , wherein said drug solution is applied by dipping, dripping, spraying, or pipeting.  
     
     
         18 . The method of  claim 15 , further comprising the step of applying an additional modifying or modulating layer after evaporating said organic solvent.  
     
     
         19 . The method of  claim 18 , wherein said additional modifying or modulating layer comprises a polymer.  
     
     
         20 . The method of  claim 18 , wherein said additional modifying or modulating layer comprises a drug.  
     
     
         21 . The method of  claim 18 , wherein the additional modifying or modulating layer has a thickness of less than about 5000 angstroms.  
     
     
         22 . The method of  claim 18 , wherein the additional modifying or modulating layer has a thickness of between about 50 and 2000 angstroms.  
     
     
         23 . The method of  claim 14 , wherein said polymer coating has a thickness of between about 1 and 10 microns.  
     
     
         24 . The method of  claim 14 , wherein said polymer coating has a thickness of between about 2 and 5 microns.  
     
     
         25 . The method of  claim 13 , wherein the organic solvent is chosen from the group consisting of: ethanol, isopropanol, chloroform, acetone, pentane, hexane, and methylene chloride.  
     
     
         26 . The method of  claim 13 , wherein the organic solvent is chloroform.  
     
     
         27 . The method of  claim 13 , wherein said at least one substantially water-insoluble drug is paclitaxel.  
     
     
         28 . The method of  claim 13 , wherein said at least one water-insoluble drug comprises a combination of paclitaxel and an agent selected from the group consisting of anti-coagulants, anti-mitotics, anti-thrombogenics, thrombolytics, anti-inflammatory agents, nitric oxide containing polymers, or vascular cell promoters.  
     
     
         29 . A method of preparing a balloon catheter having a balloon with a substantially water-insoluble drug coating, comprising: 
 a catheter for insertion into a body lumen, having a shaft and an expandable balloon at a distal end of the shaft,    said balloon having a polymer coating on at least a portion of an exterior surface,    said polymer coating having a thickness of between about 0.2 and 50 microns,    said polymer coating containing at least one substantially water-insoluble drug, said method comprising the steps of:    dissolving said at least one substantially water-insoluble drug in an organic solvent to create a drug solution; and    applying said drug solution to at least a portion of the exterior surface of said balloon.