Microparticle coated medical device

• US 8,603,536 B2
• Filed: 09/15/2003
• Issued: 12/10/2013
• Est. Priority Date: 05/09/2001
• Status: Expired due to Fees

• Current Assignee: Advanced Cardiovascular Systems Incorporated
• Original Assignee: Advanced Cardiovascular Systems Incorporated
• Inventors: Wu, Steven Z., Hossainy, Syed F. A., Harish, Sameer, Sanders-Millare, Deborra, Mirzaee, Daryush
• Primary Examiner(s): Wax, Robert A
• Assistant Examiner(s): WORSHAM, JESSICA N
• Application Number:
  US10/663,568
• Publication Number:
  US 20040052859A1
• Time in Patent Office: 3,739 Days
• Field of Search: 424/489, 424/490, 424/497
• US Class Current: 424/490
• CPC Class Codes: A61K 9/1635 obtained by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polyvinyl pyrrolidone, poly(meth)acrylates
• CPC Class Codes: A61K 9/1652 Polysaccharides, e.g. alginate, cellulose derivatives; Cyclodextrin homeopathic globules A61K9/1623
• CPC Class Codes: A61L 2300/416 Anti-neoplastic or anti-proliferative or anti-restenosis or anti-angiogenic agents, e.g. paclitaxel, sirolimus
• CPC Class Codes: A61L 2300/606 Coatings
• CPC Class Codes: A61L 2300/622 Microcapsules
• CPC Class Codes: A61L 31/10 Macromolecular materials
• CPC Class Codes: A61L 31/16 Biologically active materials, e.g. therapeutic substances A61L31/047 takes precedence
• CPC Class Codes: C08L 29/04 Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids

Abstract

A drug-loaded microparticle is applied to a medical device for subsequent application to biological tissues. A method of formulating a drug-loaded microparticle and applying it to the surface of a medical device, such as a stent, is disclosed. The drug-loaded microparticle is formulated by combining a drug with various chemical solutions. Specified sizes of the microparticles and amounts of drug(s) contained within the microparticles may be varied by altering the proportions of the chemicals/solutions. In addition to various drugs, therapeutic substances and radioactive isotopes may also be loaded into the microparticles. The drug-loaded microparticle are suspended in a polymer solution forming a polymer matrix. The polymer matrix may be applied to the entire surface or only selected portions of the medical device via dipping, spraying or combinations thereof.

Claims

1. A drug loaded stent, comprising:

a radially expandable stent body,

a coating layer disposed on the stent body, and

polymeric particles containing a therapeutic substance embedded within the coating layer, wherein the coating layer comprises a polymer different than the polymer from which the particles are made, wherein the coating layer is free from any therapeutic substances.

2. The stent of claim 1, wherein the polymeric particles are made from a hydrogel material.

3. The stent of claim 1, wherein the particles are 0.5 to 2 microns in size.

4. The stent of claim 1, wherein the therapeutic substance is for the treatment of restenosis.

5. The stent of claim 1, wherein the therapeutic substance is a radioactive isotope.

7. The stent of claim 1, wherein the therapeutic substance is completely encased within the polymeric particles.

6. A medical device, comprising an implantable substrate and a coating layer, wherein the coating layer is free from any therapeutic substances but includes particles of a polymeric material having a therapeutic substance added thereto, wherein the therapeutic substance is completely encased within the polymer particles.

8. The medical device of claim 6, wherein the coating layer comprises a polymer different than the polymer from which the particles are made.

9. An implantable medical device made by the method comprising:

adding polymeric particles containing a therapeutic substance to a fluid form of an implantable medical device coating material, wherein the coating material includes a polymeric material dissolved in a solvent, and wherein the polymeric particles containing the therapeutic substance are suspended in the polymeric material dissolved in the solvent;

applying the fluid form of the coating material comprising the polymeric particles added thereto to an implantable medical device; and

solidifying the coating material to a film layer by allowing the solvent to evaporate, wherein the film layer includes the polymeric particles containing the therapeutic substance.

10. The implantable medical device of claim 9, wherein the film layer includes the polymeric material encasing the polymeric particles.