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 method of preparing an angioplasty balloon catheter having a balloon with an exterior surface, the method comprising:
 mixing at least one drug with a volatile solvent to create a drug solution, the at least one drug comprising paclitaxel and the volatile solvent comprising at least one volatile organic solvent optionally in mixture with water;   applying said drug solution to said exterior surface of the balloon and   evaporating the volatile solvent.   
     
     
         2 . The method of  claim 1 , wherein said drug mixture is applied by dipping or spraying. 
     
     
         3 . The method of  claim 1 , wherein a predetermined amount of said solution of known concentration is applied to the balloon to provide a balloon with a predetermined loading of paclitaxel thereon. 
     
     
         4 . The method of  claim 3 , wherein the solution is applied from a pipette. 
     
     
         5 . The method of  claim 1 , wherein said volatile solvent comprises ethanol. 
     
     
         6 . The method of  claim 1 , wherein said volatile solvent is a mixture of a volatile organic solvent and water. 
     
     
         7 . The method of  claim 1 , wherein said at least one drug consists of paclitaxel. 
     
     
         8 . The method of  claim 1 , further comprising the step of applying a modulating layer comprising a polymer to said balloon after evaporating said solvent. 
     
     
         9 . The method of  claim 8 , wherein the modulating layer has a thickness of about 50 Angstroms to about 5000 Angstroms. 
     
     
         10 . The method of  claim 9 , wherein the modulating layer has a thickness of about 50-2000 Angstroms. 
     
     
         11 . The method of  claim 8 , wherein said modulating layer further comprises a drug. 
     
     
         12 . The method of  claim 13 , wherein the modulating layer comprises a silicone. 
     
     
         13 . The method of  claim 1 , wherein said at least one drug comprising paclitaxel further comprises a second drug selected from the group consisting of anticoagulants, anti-inflammatory agents, antimitotics, antithrombogenics, thrombolytics, nitric oxide-containing polymers, vascular cell promoters, growth factors, and mixtures thereof. 
     
     
         14 . The method of  claim 1 , wherein the at least one drug further comprises a member of the group consisting of dexamethasone, prednisolone, corticosterone, budesonide, estrogen, sulfasalazine, mesalamine, 5-fluorouracil, cisplatin, vinblastine, vincristine, epothilones, endostatin, angiostatin, thymidine kinase inhibitors, lidocaine, bupivacaine, ropivacaine, and mixtures thereof. 
     
     
         15 . The method of  claim 1 , wherein the drug solution is applied to the balloon while the balloon is in a substantially deflated state. 
     
     
         16 . The method of  claim 1 , wherein the drug solution is applied to the balloon while the balloon is in an inflated state. 
     
     
         17 . The method of  claim 1 , wherein the total amount of paclitaxel on the balloon after evaporating said volatile solvent is in the range of from about 200 μg to about 1532 μg. 
     
     
         18 . A method of preparing an angioplasty balloon catheter having a balloon with an exterior surface, the method comprising:
 mixing at least one drug with a volatile solvent to create a drug solution, the at least one drug selected from the group consisting of paclitaxel dexamethasone, prednisolone, corticosterone, budesonide, estrogen, sulfasalazine, mesalamine, 5-fluorouracil, cisplatin, vinblastine, vincristine, epothilones, endostatin, angiostatin, thymidine kinase inhibitors, lidocaine, bupivacaine, ropivacaine, and mixtures thereof, and the volatile solvent comprising at least one volatile organic solvent optionally in mixture with water;   applying said drug solution to said exterior surface of the balloon and   evaporating the volatile solvent.   
     
     
         19 . A method of delivering paclitaxel, to an inner wall of a blood vessel of a patient from an angioplasty catheter having an expandable balloon with the paclitaxel on an outer surface of the balloon, the method comprising:
 providing a balloon of a balloon catheter having a layer consisting of dried paclitaxel on the outer surface of the balloon; and   employing the catheter for vessel dilatation.   
     
     
         20 . A method of delivering paclitaxel to an inner wall of a blood vessel the method comprising:
 providing a balloon catheter having a balloon with an outer surface and a dried layer containing the paclitaxel on the outer surface of the balloon;   advancing the balloon within the blood vessel to a treatment site within the blood vessel;   inflating the balloon at the treatment site to contact the balloon with an inner wall of the blood vessel; and   maintaining the inflated balloon in contact with the inner wall of the blood vessel so as to transfer paclitaxel to the inner wall of the blood vessel.   
     
     
         21 . The method of  claim 20 , wherein the blood vessel is a coronary artery. 
     
     
         22 . The method of  claim 20 , wherein at said providing step, the balloon includes a total of from about 152 μg to about 1532 μg of paclitaxel in said dried layer. 
     
     
         23 . The method of  claim 20 , wherein the method is performed without implanting a stent within the blood vessel. 
     
     
         24 . The method of  claim 20 , wherein the balloon comprises a material selected from the group consisting of: a polyamide, polyolefins, polyesters and copolymers thereof. 
     
     
         25 . The method of  claim 20 , wherein the dried layer consists essentially of about 200 μg to about 1532 μg of paclitaxel. 
     
     
         26 . The method of  claim 20 , wherein the time the inflated balloon is in contact with the inner wall of the blood vessel corresponds to said maintaining step. 
     
     
         27 . A method of delivering paclitaxel to an inner wall of a blood vessel of a patient from an implantable medical device having an expandable balloon with the paclitaxel on an outer surface of the balloon, the method comprising the steps of:
 providing an angioplasty balloon having a dried layer of coating material containing paclitaxel on the outer surface of the balloon, wherein the dried layer of coating material is the outermost layer on the balloon, wherein the balloon has folds, and wherein portions of the dried layer are positioned in the folds;   advancing the balloon within the blood vessel to a treatment site within the blood vessel;   inflating the balloon at the treatment site so as to cause the folds to open so that portions of the balloon come into contact with the inner wall of the blood vessel during which amounts of the coating material containing paclitaxel are transferred to the inner wall of the blood vessel;   maintaining the inflated balloon in contact with the inner wall of the blood vessel;   deflating the balloon after said maintaining; and   removing the deflated balloon from the blood vessel.   
     
     
         28 . A method of delivering paclitaxel to an inner wall of a blood vessel from a balloon catheter having an expandable balloon with a coating on an outer surface of the balloon, the method comprising:
 providing a balloon catheter including a balloon with a dried coating consisting of paclitaxel or a mixture of paclitaxel with another bioactive agent, the dried coating being free of any additional coating atop the dried coating;   advancing the balloon within the blood vessel to a treatment site;   inflating the balloon to directly contact the paclitaxel or mixture of paclitaxel with another bioactive agent with an inner wall of the blood vessel; and   delivering the paclitaxel or mixture of paclitaxel with another bioactive agent to the inner wall of the blood vessel while maintaining the paclitaxel or mixture of paclitaxel with another bioactive agent in direct contact with the inner wall of the blood vessel while the balloon is inflated.   
     
     
         29 . A method of delivering paclitaxel to an inner wall of a blood vessel of a patient from an implantable medical device having an expandable balloon with the paclitaxel on an outer surface of the balloon, the method comprising the steps of:
 providing an angioplasty balloon having a dried layer of coating material consisting essentially of paclitaxel on the outer surface of the balloon, wherein the dried layer of coating material is the outermost layer on the balloon, wherein the balloon has folds, and wherein portions of the dried layer are positioned in the folds;   advancing the balloon within the blood vessel to a treatment site within the blood vessel;   inflating the balloon at the treatment site so as to cause the folds to open so that portions of the balloon come into contact with the inner wall of the blood vessel during which amounts of the coating material containing paclitaxel are transferred to the inner wall of the blood vessel;   maintaining the inflated balloon in contact with the inner wall of the blood vessel;   deflating the balloon after said maintaining; and   removing the deflated balloon from the blood vessel.