Coatings for medical devices

Abstract

A method and device for local delivery of a water-insoluble therapeutic agent to the tissue of a normal or diseased body lumen is disclosed. An expandable structure of a medical disposable device, such as a balloon of a balloon catheter, is coated with a non-durable coating which includes an amphiphilic polymer or copolymer, in embodiments polyethylene glycol, having a substantially water-insoluble therapeutic agent dispersed therein. In some embodiments, the coating may also include iodine. The medical disposable device is inserted into a body lumen, and expanded to contact the non-durable coating against the body lumen and deliver the substantially water-insoluble therapeutic agent to the body lumen tissue.

What is claimed is: 
     
         1 . A catheter assembly for insertion into the vasculature comprising:
 a catheter shaft;   a balloon coupled to the catheter shaft, the balloon comprising an outer surface; and   an amphiphilic coating disposed on the outer surface of the balloon;   wherein the amphiphilic coating has a thickness from about 0.01 μm to about 10 μm, and   wherein the amphiphilic coating comprises a therapeutic agent and a therapeutic agent density of about 0.1 μg/mm 2  to about 1.5 μg/mm 2 .   
     
     
         2 . The catheter assembly of  claim 1 , wherein the amphiphilic coating further comprises iodine. 
     
     
         3 . The catheter assembly of  claim 1 , wherein the amphiphilic coating further comprises iodine in an amount from about 1% to about 4%, wherein the amount is measured in dry weight of said amphiphilic coating. 
     
     
         4 . The catheter assembly of  claim 1 , wherein the amphiphilic coating further comprises a polymer matrix. 
     
     
         5 . The catheter assembly of  claim 4 , wherein the polymer matrix comprises at least one amphiphilic polymer. 
     
     
         6 . The catheter assembly of  claim 5 , wherein the polymer matrix complexed with iodine. 
     
     
         7 . The catheter assembly of  claim 6 , wherein the amphiphilic coating comprises an amount of iodine from about 1% to about 4%, wherein the amount is measured in dry weight of said amphiphilic coating. 
     
     
         8 . The catheter assembly of  claim 7 , wherein the therapeutic agent is dispersed throughout the polymer matrix. 
     
     
         9 . The catheter assembly of  claim 8 , wherein the therapeutic agent is paclitaxel. 
     
     
         10 . The catheter assembly of  claim 5 , wherein the polymer matrix comprises a polymer selected from the group consisting of polyethylene glycol, polyvinyl pyrrolidone and hydroxypropyl cellulose. 
     
     
         11 . The catheter assembly of  claim 10 , wherein the polymer comprises polyethylene glycol. 
     
     
         12 . The catheter assembly of  claim 11 , wherein the polyethylene glycol has a molecular weight of 1.5 KD to 50 KD. 
     
     
         13 . The catheter assembly of  claim 12 , wherein the polymer matrix is complexed with iodine. 
     
     
         14 . The catheter assembly of  claim 11 , wherein the polymer matrix complexed with iodine. 
     
     
         15 . The catheter assembly of  claim 14 , wherein the amphiphilic coating comprises an amount of iodine from about 1% to about 4%, wherein the amount is measured in dry weight of said amphiphilic coating. 
     
     
         16 . The catheter assembly of  claim 15 , wherein the therapeutic agent is dispersed throughout the polymer matrix. 
     
     
         17 . The catheter assembly of  claim 16 , wherein the amphiphilic coating has a therapeutic agent density of from about 0.25 μg/mm 2  to about 0.8 μg/mm 2 . 
     
     
         18 . The catheter assembly of  claim 17 , wherein the therapeutic agent is paclitaxel. 
     
     
         19 . The catheter assembly of  claim 16 , wherein the amphiphilic coating has a therapeutic agent density of from about 0.25 μg/mm 2  to about 0.8 μg/mm 2 . 
     
     
         20 . A method comprising:
 introducing a catheter assembly of  claim 1  into a patient's vasculature;   expanding the balloon in the vasculature for a period from about 5 seconds to about 300 seconds so the amphiphilic coating contacts a wall of a body lumen and transfers the therapeutic agent to the wall of the body lumen.