US5879697A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drug-releasing coatings for medical devices
Assignee: Boston Scientific Scimed Inc
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Filing: 1997-04-30
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Granted: 1999-03-09
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Expires: 2017-04-30
Abstract
Abstract The invention is directed to medical devices having a drug-releasing coating and methods for making such coated devices. The coating permits timed or prolonged pharmacological activity on the surface of medical devices through a reservoir concept. Specifically, the coating comprises at least two layers: an outer layer containing at least one drug-ionic surfactant complex overlying a reservoir layer containing a polymer and the drug which is substantially free of an ionic surfactant. Upon exposure to body tissue of a medical device covered with such coating, the ionically bound drug in the outer layer is released into body fluid or tissue. Following release of such bound drug, the ionic surfactant binding sites in the outer layer are left vacant. To maintain the pharmacological activity after delivery of the ionically bound drug, additional amounts of the drug are embedded or incorporated in the reservoir layer in a manner which allows the drug, which is substantially free of ionic surfactants, to complex with the vacant binding sites of the ionic surfactant of the outer layer. As a result, the surface of the medical device is enriched with the drug to provide sustained pharmacological activity to prevent the adverse reaction due to the presence of the medical device. The invention is further directed to medical devices with stabilized drug-releasing coatings. The coatings are stabilized by exposure to a low energy, relatively non-penetrating energy source, e.g., gas plasma or an electron beam energy source.
Inventors
- 👤 Ni Ding
- 👤 Jennifer E. Raeder-Devens
- 👤 Tuyethoa Thi Trinh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 06:14
CPC Classifications
A; A61; A61L; A61L27/00; A61L27/50; A61L27/28; A61L27/34; A61L29/00; A61L29/08; A61L29/085; A61L29/14; A61L29/16; A61L31/00; A61L31/08; A61L31/10; A61L31/14; A61L31/16; A61L2300/00; A61L2300/20; A61L2300/23; A61L2300/236; A61L2300/258; A61L2300/40; A61L2300/41; A61L2300/412; A61L2300/414; A61L2300/42; A61L2300/60; A61L2300/602; A61L2300/606; A61L2300/608; A61L2300/61; A61L2300/80; A61L2300/802
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
160 words
A medical device having at least a portion which is insertable or implantable into the body of a patient, wherein the portion has a surface which is adapted for exposure to body tissue of the patient and wherein at least a part of the surface is covered with a coating for release of at least one biologically active material, the coating comprising an internal reservoir layer and an outer layer in contact with the reservoir layer; wherein the outer layer comprises an ionic surfactant complexed to the biologically active material; and wherein the reservoir layer comprises a polymer incorporating the biologically active material which is substantially free of any ionic surfactant such that the biologically active material of the reservoir layer can migrate outwardly from the reservoir layer, and at least some of the biologically active material of the reservoir can complex with the ionic surfactant in the outer layer as the biologically active material releases from the outer layer.
Claim 2
Dependent Claim
160 words
A medical device having at least a portion which is insertable or implantable into the body of a patient, wherein the portion has a surface which is adapted for exposure to body tissue of the patient and wherein at least a part of the surface is covered with a coating for release of at least one biologically active material, the coating comprising an internal reservoir layer and an outer layer in contact with the reservoir layer; wherein the outer layer comprises an ionic surfactant complexed to the biologically active material; and wherein the reservoir layer comprises a polymer incorporating the biologically active material which is substantially free of any ionic surfactant such that the biologically active material of the reservoir layer can migrate outwardly from the reservoir layer, and at least some of the biologically active material of the reservoir can complex with the ionic surfactant in the outer layer as the biologically active material releases from the outer layer.
Claim 3
Dependent Claim
12 words
The device of claim 1 wherein the device is an expandable stent.
Claim 4
Dependent Claim
12 words
The device of claim 2 wherein the device is a self-expanding stent.
Claim 5
Dependent Claim
16 words
The device of claim 1 wherein the polymer of the reservoir layer is an elastomeric material.
Claim 6
Dependent Claim
32 words
The device of claim 4 wherein the polymer of the reservoir layer is selected from the group consisting of silicones, polyurethanes, thermoplastic elastomers, ethylene vinyl acetate copolymers, polyolefin elastomers, and EPDM rubbers.
Claim 7
Dependent Claim
14 words
The device of claim 5 wherein the polymer of the reservoir layer is silicone.
Claim 8
Dependent Claim
29 words
The device of claim 1 wherein the biologically active material of the reservoir layer is in a particulate form having an average particle size of 1 to 100 microns.
Claim 9
Dependent Claim
21 words
The device of claim 7 wherein the ratio of reservoir layer thickness to average particle diameter is greater than about 3.
Claim 10
Dependent Claim
21 words
The device of claim 7 wherein the ratio of reservoir layer thickness to average particle diameter is greater than about 5.
Claim 11
Dependent Claim
41 words
The device of claim 1 wherein the biologically active material is selected from the group consisting of glucocorticoids, heparin, hirudin, angiopeptin, aspirin, ACE inhibitors, growth factors, oligonucleotides, antiplatelet agents, anti-hypertensives, anti-coagulant agents, antimitotic agents, antioxidants, antimetabolite agents, anti-inflammatory agents and antibiotics.
Claim 12
Dependent Claim
12 words
The device of claim 10 wherein the biologically active material is heparin.
Claim 13
Dependent Claim
22 words
The device of claim 1 wherein the reservoir layer comprises about 0.1 to about 90 weight % of the biologically active material.
Claim 14
Dependent Claim
22 words
The device of claim 12 wherein the reservoir layer comprises about 10 to about 45 weight % of the biologically active material.
Claim 15
Dependent Claim
17 words
The device of claim 1 wherein the reservoir layer is about 5 to about 200 microns thick.
Claim 16
Dependent Claim
17 words
The device of claim 14 wherein the reservoir layer is about 15 to about 50 microns thick.
Claim 17
Dependent Claim
18 words
The device of claim 1 wherein the ionic surfactant of the outer layer is a quaternary ammonium complex.
Claim 18
Dependent Claim
13 words
The device of claim 16 wherein the ionic surfactant comprises a tridodecylmethylammonium ion.
Claim 19
Dependent Claim
17 words
The device of claim 1 wherein the outer layer is about 0.1 to about 10 microns thick.
Claim 20
Dependent Claim
27 words
The device of claim 1 wherein the coating is constructed to maintain biologically active material on the surface of the device for at least about 24 hours.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-03-08 | 2002-09-07 | 2003-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-03-08 | 2006-09-07 | 2007-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-03-08 | 2010-09-07 | 2011-03-09 | $7700.00 | Window Closed / Lapsed |