Use of nanocrystals for drug delivery from a balloon
A drug delivery balloon ( 10 ) has a drug thereon in the form of crystalline particles ( 12 ), the drug having a predetermined size distribution. Optionally marker particles ( 14, 16 ) are also provided. A texturized coating ( 18 ), a cap layer ( 20 ) and/or other methods may be used to increase particle loading capacity of the balloon.
1. A drug delivery balloon adapted for delivery of a drug to a site in a body passageway, the balloon comprising a balloon wall with an outer surface, and the balloon having a drug disposed on the outer surface, wherein the drug includes a plurality of crystalline drug particles provided directly on and contacting an outer surface of the balloon, wherein the crystalline drug particles comprise paclitaxel, the crystalline drug particles having a predetermined size distribution, wherein said size distribution is in a range of from 0.01 μm to 0.1 μm, wherein the crystalline drug particles are present in mixture with a water soluble excipient material, wherein the water soluble excipient material forms a fibrous matrix holding the crystalline drug particles, wherein a plurality of non-radioactive tracer particles are mixed with the crystalline drug particles, wherein the non-radioactive tracer particles are detectable by one or more of X-Ray, magnetic resonance imaging, or ultrasound.
2. A drug delivery balloon as in claim 1 wherein said crystalline drug particles comprise at least 95% by weight of said drug.
3. A drug delivery balloon as in claim 2 wherein said crystalline drug particles comprise an anti-agglomeration agent in an amount of less than 1% by weight.
4. A drug delivery balloon as in claim 1 wherein the tracer particles are admixed with drug particles on the balloon.
5. A drug delivery balloon as in claim 4 wherein said tracer particles are of similar size distribution and in a predetermined ratio whereby the amount of drug delivered to the site can be estimated on the basis of detection of the tracer particles.
6. A drug delivery balloon as in claim 4 comprising a plurality of different tracer particles that differ in the manner that they are detectable.
7. A drug delivery balloon as in claim 1 wherein said excipient is a member of the group consisting of water soluble polymers, sugars, polysaccharides, contrast agents, citrate esters, and pharmaceutically acceptable salts.
8. A drug delivery balloon as in claim 1 wherein the balloon comprises textured surface that provides increased particle retention.
9. A drug delivery balloon as in claim 1 wherein the balloon has a capping layer over crystalline drug particles that is water soluble and biodegradable and that breaks free from the balloon upon balloon expansion.
10. A drug delivery balloon as in claim 1 having an amount of crystalline dihydrate paclitaxel on the balloon of from 50 to 1000 μg.
11. A drug delivery balloon comprising a coating thereon and a drug applied over the coating, wherein the coating has a textured surface that increases the drug carrying capacity of the balloon, wherein the drug is provided as crystalline particles free from a polymeric material along an outer surface of the crystalline particles, the crystalline particles are held in a fibrous matrix defined by a water soluble excipient material, wherein the crystalline particles having a predetermined size distribution in a range of from 0.01 μm to 0.1 μm, wherein a plurality of non-radioactive tracer particles are mixed with the crystalline particles.
12. A drug delivery balloon as in claim 11 wherein said coating is formed of a soft silicone or urethane material.