Patent Title:
Implantable medical device coatings with biodegradable elastomer and releasable taxane agent
Assignee:
Inventors:
Aparna Reddy Sarasam, Angela Rose Barnett, Krista Nicole Gearhart, Jason Lichti, Priscilla Reyes
Patent:
Summary Related to Ultrasonic Spray Nozzle used for a stent coated with paclitaxel:
Stents with coatings consisting of paclitaxel coatings including both the dihydrate solid form and in the amorphous solid forms of paclitaxel are prepared by spray coating a solution comprising paclitaxel, methanol and water. A paclitaxel solution in methanol and water is prepared. Specifically, a 1.74 mM paclitaxel solution is prepared in 68% methanol by dissolving 7.43 mg of paclitaxel in 5 mL of previously made solution of 68% methanol 32% water. The solution is sprayed from an ultrasonic spray gun in a glove box. Before spraying, the glove box is purged with nitrogen at 20 psi for 15 minutes. The atmosphere in the glove box is adjusted until the oxygen meter reads a constant 200 ppm within the glove box. The heat in the glovebox is set to 31° C. (88° F.), the air shroud to 2.0 psi and the ultrasonic power to 1.0 W. The paclitaxel solution is loaded into a syringe and place on the syringe pump in the ultrasonic coating apparatus and a bare metal stent (6×20 ZILVER, Cook Inc., Bloomington, Ind.) is mounted on a mandrel aligned with the spray nozzle. The solution is sprayed onto a stent using a 60 kHz nozzle at a flow rate of 0.03 mL/min, a coating velocity of 0.025 in/sec, a nozzle power of 1.0 W, a process gas pressure of 2.0 psi, and a distance from the nozzle to the stent of about 12 mm, while rotating the stent with an axial rotation rate of 60 rpm. Only the abluminal surface of the stent is coated.
Stent Coating Parameters
Flow Rate (mL/min): 0.01-2
Coating Velocity (in/sec): 0.01-.05
Rotation Speed (rpm): 30-150
Nozzle Power (watts): 0.9-1.2
Process Gas (psi): 0.1-2.5
Distance (mm): 1-25
