Method and apparatus for loading a beneficial agent into an expandable medical device
View Patent ↗The present invention relates to method and apparatus for dispensing a beneficial agent into an expandable medical device. The method includes the step of placing an expandable medical device on a support and dispensing a beneficial agent into a plurality of openings in the medical device with a shield gas for controlling a local environment surrounding the dispenser.
1. A method for loading a medical device with a beneficial agent, the method comprising:
providing a medical device with a plurality of holes;
dispensing a beneficial agent through a dispenser into the plurality of holes in a dropwise manner; and
controlling a local environment surrounding a dispensing tip of the dispenser to prevent clogging of the dispenser tip by delivering a shield gas adjacent the tip; and
wherein the shield gas is delivered from an orifice within about 1 inch of the dispensing tip of the dispenser.
2. The method of claim 1 , wherein the local environment is controlled by delivering a shield gas comprising a dry gas to an area surrounding a dispensing tip of the dispenser to control a humidity of the gas in the local environment.
3. The method of claim 2 , wherein the dry gas is selected from the group consisting of nitrogen, helium, argon, dry air, inert gases, and combinations thereof.
4. The method of claim 1 , wherein the shield gas is delivered by providing a liquid source and evaporating the liquid to create the shield gas.
5. The method of claim 1 , wherein the beneficial agent includes a solvent which absorbs water from the environment.
6. The method of claim 1 , wherein the beneficial agent includes a lipophilic drug which crystallizes in the presence of water.
7. The method of claim 6 , wherein the drug is a lipophilic drug.
8. The method of claim 1 , wherein the beneficial agent includes a biological compound and the shield gas is a reducing atmosphere.
9. The method of claim 1 , wherein the shield gas is controlled to maintain a humidity at the dispensing tip below a predetermined humidity.
10. The method of claim 1 , further comprising sensing a humidity and controlling an amount of the shield gas delivered depending on the sensed humidity.
11. The method of claim 1 , wherein the dispenser is a dropwise dispenser.
12. The method of claim 1 , wherein the local environment is controlled by delivering the shield gas and the shield gas comprises a dry gas delivered to an area surrounding a dispensing tip of the dispenser to control a humidity of the gas in the local environment.
13. The method of claim 12 , wherein the dry gas is selected from the group consisting of nitrogen, helium, argon, dry air, inert gases, and combinations thereof.