Methods of forming microparticle coated medical device

• US 8,361,539 B2
• Filed: 09/15/2003
• Issued: 01/29/2013
• 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): Tran, Susan
• Assistant Examiner(s): WORSHAM, JESSICA N
• Application Number:
  US10/663,181
• Publication Number:
  US 20040052858A1
• Time in Patent Office: 3,424 Days
• Field of Search: 424/489, 424/490, 424/497
• US Class Current: 427/2.25
• 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 method of coating a stent comprising:

adding polymeric particles containing a therapeutic substance to a fluid form of a stent coating material, wherein the coating material comprises a polymeric material dissolved in a solvent, such that the polymeric particles containing the therapeutic substance are suspended in the coating material;

applying the fluid form of the coating material comprising the polymeric particles added thereto to a stent; and

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

2. The method of claim 1, wherein the polymeric particles are made by water-in-oil emulsion.

3. The method of claim 1, wherein the polymeric particles have a hydrogel consistency.

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

5. The method of claim 1, wherein the film layer comprises the polymeric material encasing the polymeric particles.

6. The method of claim 1, wherein the polymeric material dissolved in the solvent is selected from the group consisting of polyvinyl alcohol, ethylene-vinyl alcohol copolymers, polyurethanes, and copolymers and mixtures thereof.

7. The method of claim 6, wherein the polymeric material dissolved in the solvent is a polyurethane.

8. The method of claim 6, wherein the polymeric material dissolved in the solvent is polyvinyl alcohol.

9. The method of claim 6, wherein the polymeric material dissolved in the solvent is an ethylene-vinyl alcohol copolymer.

10. The method of claim 1, wherein the coating material further comprises a second therapeutic substance that may be the same as or different from the therapeutic substance of the polymeric particles.

11. The method of claim 1, wherein a polymer of the polymeric particles is different from the polymeric material of the coating material.

12. The method of claim 1, wherein the coating material is free from any therapeutic substances.

13. The method of claim 1, wherein the film layer is free from any therapeutic substances such that the therapeutic substance is encased only in the polymeric particles.

14. The method of claim 13, wherein a polymer of the polymeric particles is different from the polymeric material of the coating material.

15. The method of claim 1, wherein the polymeric particles comprise a polymer, the constituent monomer of the polymer or at least one constituent monomer of the polymer being vinyl pyrrolidone.

16. The method of claim 1, wherein the polymeric particles comprise a polymer, the constituent monomer of the polymer or at least one constituent monomer of the polymer being polyethylene glycol diacrylate.

17. The method of claim 1, wherein the polymeric particles comprise poly(alginate).

18. The method of claim 1, wherein the polymeric particles comprise cellulose acetate phthalate.