Coating for implantable medical devices

• US 7,247,364 B2
• Filed: 02/25/2005
• Issued: 07/24/2007
• Est. Priority Date: 02/26/2003
• Status: Expired due to Fees

• Current Assignee: Advanced Cardiovascular Systems Incorporated
• Original Assignee: Advanced Cardiovascular Systems Incorporated
• Inventors: Tang, Yiwen, Pacetti, Stephen D., Hossainy, Syed F. A., Tung, Andrew C.
• Primary Examiner(s): Chen; Vivian
• Application Number:
  US11/067,375
• Publication Number:
  US 20050143808A1
• Time in Patent Office: 879 Days
• Field of Search: None
• US Class Current: 428/212
• CPC Class Codes: A61F 2/0077 Special surfaces of prostheses, e.g. for improving ingrowth A61F2/30767 takes precedence
• CPC Class Codes: A61F 2/06 Blood vessels
• CPC Class Codes: A61F 2250/0067 Means for introducing or releasing pharmaceutical products into the body
• CPC Class Codes: Y10T 428/13 Hollow or container type article [e.g., tube, vase, etc.]
• CPC Class Codes: Y10T 428/24942 including components having same physical characteristic in differing degree
• CPC Class Codes: Y10T 428/3154 Of fluorinated addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31786 Of polyester [e.g., alkyd, etc.]
• CPC Class Codes: Y10T 428/31855 Of addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31935 Ester, halide or nitrile of addition polymer

Abstract

An implantable medical device, such as a stent, is disclosed having a coating. The coating includes a poly(butylene terephthalate-co-ethylene glycol)polymer. The coating can also include a drug.

Claims

1. An implantable medical device, comprising a coating, the coating including a poly(butylene terephthalate-co-ethylene glycol)polymer,

wherein the poly(butylene terephthalate-co-ethylene glycol)polymer comprises hydrophilic units derived from ethylene glycol between about 40% and about 90 molar % of the total units of the PBT-PEG polymer, and

wherein the coating is formed-by a method comprising a post-coating process to cause the hydrophilic units to be extracted or bloom to the coating-air interface.

2. The implantable medical device of claim 1, wherein the implantable medical device is a stent.

3. The imp lantable medical device of claim 1, wherein the ratio between the units derived from ethylene glycol and the units derived from butylene terephthalate is between about 0.67:

1 and 9;

1.

4. The implantable medical device of claim 1, additionally including a therapeutic substance.

5. The implantable medical device of claim 4, wherein the therapeutic substance is selected from a group of paclitaxel, docetaxel, rapamycin, 40-O-(2-hydroxy)ethyl-rapamycin, 40-O-(3-hydroxy)propyl-rapamycin, 40-O-[2-(2-hydroxy)ethoxy]ethyl-rapamycin, and 40-O-tetrazole-rapamycin, and analogs thereof.

6. The implantable medical device of claim 1, wherein the ethylene glycol units constitute 40 to 90 mole % of the polymer.

7. The implantable medical device of claim 1, wherein the ethylene glycol units constitute 55 to 80 mole % of the polymer.

8. An implantable medical device, comprising a coating, the coating including a first region comprising poly(butylene terephthalate-co-ethylene glycol) and a second region comprising poly(butylene terephthalate-co-ethylene glycol), wherein the mole % of the ethylene glycol is higher in the second region than the first region,

wherein units of ethylene glycol in poly(butylene terephthalate-co-ethylene glycol) of the first region or units of ethylene glycol in poly(butylene terephthalate-co-ethylene glycol) of the second region were extracted or bloomed to the coating-air interface.

9. The implantable medical device of claim 8, wherein the device is a stent.

10. The implantable medical device of claim 8, wherein the second region is over the first region.

11. The implantable medical device of claim 8, wherein the second region is the outermost layer of the coating.

12. The implantable medical device of claim 8, wherein the second region is the outermost layer of the coating and the first region is a reservoir layer including a drug and which is positioned beneath the outermost layer.

13. The implantable medical device of claim 8, wherein the coating additionally includes a therapeutic substance.

14. The implantable medical device of claim 13, wherein the therapeutic substance is selected from a group of paclitaxel, docetaxel, rapamycin, 40-O-(2-hydroxy)ethyl-rapamycin, 40-O-(3-hydroxy)propyl-rapamycin, 40-O-[2-(2-hydroxy)ethoxy]ethyl-rapamycin, and 40-O-tetrazole-rapamycin, and analogs thereof.