Direct fluid coating of drug eluting balloon

Abstract

A system and method for coating an expandable member of a medical device comprises providing a dispenser in fluid communication with a fluid source with the dispenser having at least one outlet to dispense fluid of the fluid source therefrom. The outlet(s) of the dispenser is positioned proximate a surface of an expandable member, with relative movement between the outlet(s) and the surface of the expandable member established along a coating path, and fluid is dispensed from the dispenser to form a substantially continuous bead of fluid between the at least one outlet and the surface of the expandable member along the coating path, and simultaneously drying the fluid while dispensing the fluid from the dispenser to control flow of fluid on the surface of the expandable member. The fluid source can include a variety of therapeutic agents.

What is claimed is: 
     
         1 . A method of coating an expandable member of a medical device, comprising:
 providing a dispenser in fluid communication with a fluid source, the dispenser having at least one outlet to dispense fluid of the fluid source therefrom;   positioning the at least one outlet of the dispenser proximate a surface of an expandable member;   establishing relative movement between the at least one outlet and the surface of the expandable member along a coating path;   dispensing fluid from the dispenser to form a substantially continuous bead of fluid between the at least one outlet and the surface of the expandable member along the coating path; and   simultaneously drying the fluid while dispensing the fluid from the dispenser to control flow of fluid on the surface of the expandable member.   
     
     
         2 . The method of  claim 1 , wherein the fluid remains substantially in a location where it contacts the surface of the expandable member. 
     
     
         3 . The method of  claim 1 , wherein relative movement provides a velocity ranges approximately from 2 to 20 cm/sec. 
     
     
         4 . The method of  claim 1 , wherein the dispenser is selected from the group consisting of pipet, tubing, flexible tubing, hypotubes, dies, and ball-bearing dispense tubing. 
     
     
         5 . The method of  claim 1 , wherein the dispenser does not contact the expandable member. 
     
     
         6 . The method of  claim 1 , wherein the fluid includes a therapeutic agent. 
     
     
         7 . The method of  claim 1 , wherein the inflatable member is inflated to a pressure of approximately 0.1 to 8 atm prior to coating. 
     
     
         8 . The method of  claim 1 , wherein the dose density of therapeutic agent on the expandable member is greater than 200 μg/cm 2 . 
     
     
         9 . The method of  claim 1 , wherein the relative movement includes rotation, translation, or a combination thereof, of at least one of the expandable member and the at least one outlet. 
     
     
         10 . The method of  claim 9 , wherein the relative movement includes rotation, axial translation, or a combination thereof, of the other of the expandable member and the at least one outlet. 
     
     
         11 . The method of  claim 9 , wherein the medical device further includes a shaft extending from the expandable member, wherein during rotation and translation of the expandable member, the shaft remains straight. 
     
     
         12 . The method of  claim 9 , wherein the medical device further includes a shaft extending from the expandable member, wherein during rotation and translation of the expandable member, a rotation torque is applied to a proximal hub disposed on the shaft. 
     
     
         13 . The method of  claim 9 , wherein the relative movement includes moving the expandable member relative a first axis, and moving the at least one outlet relative a second axis. 
     
     
         14 . The method of  claim 9 , wherein the relative movement defines a helical coating path of the at least one outlet relative to the expandable member. 
     
     
         15 . The method of  claim 1 , wherein dispensing fluid to the surface of the expandable member is repeated along a plurality of coating paths. 
     
     
         16 . The method of  claim 15 , wherein a first fluid is dispensed during a first coating path, and a second fluid is dispensed during a second coating path. 
     
     
         17 . The method of  claim 1 , further comprising controlling dispensing to apply a substantially uniform coating of fluid to a predetermined area of the expandable member. 
     
     
         18 . The method of  claim 1 , wherein the at least one outlet is heated while dispensing fluid therefrom. 
     
     
         19 . The method of  claim 1 , wherein the dispenser includes a plurality of outlets offset from each other. 
     
     
         20 . A system for coating an expandable member of a medical device, the system comprising:
 a support structure to support an expandable member of a medical device;   a dispenser in fluid communication with a fluid source, the dispenser having at least one outlet for dispensing fluid of the fluid source therefrom, the dispenser positioned with the at least one outlet proximate a surface of an expandable member supported by the support structure;   a dryer proximate the dispenser to simultaneously dry the fluid while dispensing the fluid from the dispenser to control flow of fluid on the surface of the expandable member; and   a drive assembly to establish relative movement between the at least one outlet and the surface of the expandable member to dispense fluid from the dispenser as a substantially continuous bead between the at least one outlet and the surface of the expandable member along a coating path.