Implantable or Insertable Medical Devices For Controlled Delivery of a Therapeutic Agent

Abstract

The present invention is directed to novel implantable or insertable medical devices that provide controlled release of a therapeutic agent. According to an embodiment of the present invention, a therapeutic-agent-releasing medical device is provided, which comprises: (a) an implantable or insertable medical device; (b) a release layer disposed over at least a portion of the implantable or insertable medical device; and (c) a therapeutic agent. The release layer comprises a styrene copolymer and at least one additional polymer. The release layer regulates the rate of release of the therapeutic agent from the medical device upon implantation or insertion of the device into a patient. The present invention is also directed to methods of forming the above implantable or insertable medical devices, methods of administering a therapeutic agent to a patient using such devices, and methods of modulating the release of therapeutic agent from such devices.

1 - 25 . (canceled) 
     
     
         26 . A method of forming the therapeutic-agent-releasing medical device that comprises (a) an implantable or insertable medical device; (b) a release layer disposed over at least a portion of the implantable or insertable medical device, said release layer comprising (i) a styrene copolymer selected from an alternating styrene copolymer and a random styrene copolymer and (ii) an additional polymer; and (c) a therapeutic agent, said release layer regulating the rate of release of the therapeutic agent from the medical device upon implantation or insertion of the device into a patient, said method comprising: (1) providing a solution comprising: one or more solvents, said styrene copolymer and said additional polymer; (2) applying said solution to a surface of said implantable or insertable medical device; and (3) removing said solvents from said solution to form said release layer. 
     
     
         27 . The method of  claim 26 , wherein said solution further comprises said therapeutic agent. 
     
     
         28 . The method of  claim 26 , wherein said solution is applied over a therapeutic-agent-containing region that comprises said therapeutic agent. 
     
     
         29 . The method of  claim 26 , wherein said solution is applied by a solvent spraying technique. 
     
     
         30 . A method of releasing a therapeutic agent within a patient comprising (1) providing a therapeutic-agent-releasing medical device that comprises (a) an implantable or insertable medical device; (b) a release layer disposed over at least a portion of the implantable or insertable medical device, said release layer comprising (i) a styrene copolymer selected from an alternating styrene copolymer and a random styrene copolymer and (ii) an additional polymer; and (c) a therapeutic agent, said release layer regulating the rate of release of the therapeutic agent from the medical device upon implantation or insertion of the device into a patient and (2) implanting or inserting the therapeutic-agent-releasing medical device of into a patient. 
     
     
         31 . The method of  claim 30 , wherein said medical device is selected from a catheter, a guide wire, a balloon, a filter, a stent, a stent graft, a vascular graft, a vascular patch, a shunt, and an intraluminal paving system. 
     
     
         32 . The method of  claim 30 , wherein said medical device is inserted into the vasculature. 
     
     
         33 . The method of  claim 32 , wherein said therapeutic agent is released in the treatment of restenosis. 
     
     
         34 . A method of modulating a rate of release of a therapeutic agent by a release layer that (a) is disposed over at least a portion of an implantable or insertable medical device and (b) comprises (i) a styrene copolymer selected from an alternating styrene copolymer and a random styrene copolymer and (ii) an additional polymer, said method comprising changing the composition of said release layer. 
     
     
         35 . The method of  claim 34 , wherein the rate of release is modulated by changing the amount of styrene copolymer relative to the amount of the additional polymer. 
     
     
         36 . The method of  claim 35 , wherein the rate of release of the therapeutic agent is increased by increasing the amount of the styrene copolymer relative to the amount of the additional polymer, or the rate of release of the therapeutic agent is decreased by decreasing the amount of the styrene copolymer relative to the amount of the additional polymer. 
     
     
         37 . The method of  claim 34 , wherein the rate of release is modulated by changing the molecular weight of the styrene copolymer. 
     
     
         38 . The method of  claim 34 , wherein the rate of release is modulated by changing the amount of the styrene monomer relative to the total amount of monomer within the styrene copolymer. 
     
     
         39 - 42 . (canceled)