Medical Devices, Drug Coatings and Methods for Maintaining the Drug Coatings Thereon

Abstract

Medical devices, and in particular implantable medical devices, may be coated to minimize or substantially eliminate a biological organism's reaction to the introduction of the medical device to the organism. The medical devices may be coated with any number of biocompatible materials. Therapeutic drugs, agents or compounds may be mixed with the biocompatible materials and affixed to at least a portion of the medical device. These therapeutic drugs, agents or compounds may also further reduce a biological organism's reaction to the introduction of the medical device to the organism. Various materials and coating methodologies may be utilized to maintain the drugs, agents or compounds on the medical device until delivered and positioned.

1 . A device for intraluminal implantation in a vessel comprising a balloon-expandable stent and a coating, said coating comprising a biocompatible polyfluoro copolymer that comprises about eighty-five weight percent vinylidinefluoride copolymerized with about fifteen weight percent hexafluoropropylene and at least one pharmaceutical agent.  
   
   
       2 . A device according to  claim 1  wherein said polyfluoro copolymer consists essentially of 85.5 weight percent vinylidinefluoride copolymerized with 14.5 weight percent hexafluoropropylene.  
   
   
       3 . A device according to  claim 1  wherein said pharmaceutical agent and said copolymer are selected to release said pharmaceutical agent for at least 800 hours following intraluminal implantation.  
   
   
       4 . A device according to  claim 1  wherein said pharmaceutical agent and said copolymer are selected to release said agent for at least 2000 hours following intraluminal implantation.  
   
   
       5 . A device according to  claim 1  wherein said pharmaceutical agent is present in an amount that is from about 12% to about 20% by weight of the coating.  
   
   
       6 . A device according to  claim 3  wherein said agent is present in an amount that is from about 12% to about 20% by weight of the coating.  
   
   
       7 . A device according to  claim 4  wherein said agent is present in an amount that is from about 12% to about 20% by weight of the coating.  
   
   
       8 . A device according to  claim 5  wherein said polyfluoro copolymer consists essentially of 85.5 weight percent vinylidinefluoride copolymerized with 14.5 weight percent hexafluoropropylene.  
   
   
       9 . A device according to  claim 1  further comprising an additional polymer.  
   
   
       10 . A device according to  claim 5  further comprising an additional polymer.  
   
   
       11 . A device according to  claim 6  further comprising an additional polymer.  
   
   
       12 . A device according to  claim 1  wherein said balloon-expandable stent is configured for implantation in a coronary artery.  
   
   
       13 . A device according to  claim 3  wherein said balloon-expandable stent is configured for implantation in a coronary artery.  
   
   
       14 . A device according to  claim 6  wherein said balloon-expandable stent is configured for implantation in a coronary artery.  
   
   
       15 . A device according to  claim 13  wherein said polyfluoro copolymer consists essentially of 85.5 weight percent vinylidinefluoride copolymerized with 14.5 weight percent hexafluoropropylene.  
   
   
       16 . A device according to  claim 1  that releases said pharmaceutical agent at a rate of about 0.001 μg/cm 2 -min to about 100 μg/cm 2 -min.  
   
   
       17 . A device according to  claim 13  that releases said agent at a rate of about 0.001 μg/cm 2 -min to about 100 μg/cm 2 -min.  
   
   
       18 . A method for preparing a device for providing prolonged release of a pharmaceutical agent when implanted in a vessel comprising the steps of: 
 combining a pharmaceutical agent with a biocompatible polyfluoro copolymer that comprises about eighty-five weight percent vinylidinefluoride copolymerized with about fifteen weight percent hexafluoropropylene to provide a coating;    applying said coating to a balloon-expandable stent; and    heating the balloon-expandable stent comprising said coating to a maximum temperature of no greater than about 125° C.    
   
   
       19 . A method according to  claim 18 , wherein said balloon-expandable stent comprising said coating is heated to a maximum temperature of no greater than about 60° C.  
   
   
       20 . A method according to  claim 19 , wherein said polyfluoro copolymer consists essentially of 85.5 weight percent vinylidinefluoride copolymerized with 14.5 weight percent hexafluoropropylene.