Bioactive agent release coating and controlled humidity method

• US 20030232122A1
• Filed: 06/18/2002
• Published: 12/18/2003
• Est. Priority Date: 06/18/2002
• Status: Active Grant

• Current Assignee: Surmodics Incorporated
• Original Assignee: Surmodics Incorporated
• Inventors: Chappa, Ralph A., Ofstead, Ronald F., Tran, Linh V., Hergenrother, Robert W., Anderson, Aron B., Lawin, Laurie R.
• Granted Patent: US 7,097,850 B2
• Time in Patent Office: Days
• US Class Current: 427/2.1
• CPC Class Codes: A61L 2300/602 Type of release, e.g. controlled, sustained, slow
• CPC Class Codes: A61L 2300/606 Coatings
• CPC Class Codes: A61L 29/085 Macromolecular materials
• CPC Class Codes: A61L 29/16 Biologically active materials, e.g. therapeutic substances A61L29/048 takes precedence
• 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

Abstract

A coating composition in the form of a one or multi-part system, and method of applying such a composition under conditions of controlled humidity, for use in coating device surfaces to control and/or improve their ability to release bioactive agents in aqueous systems. The coating composition is particularly adapted for use with medical devices that undergo significant flexion and/or expansion in the course of their delivery and/or use, such as stents and catheters. The composition includes the bioactive agent in combination with a first polymer component such as polyalkyl(meth)acrylate, polyaryl(meth)acrylate, polyaralkyl(meth)acrylate, or polyaryloxyalkyl(meth)acrylate and a second polymer component such as poly(ethylene-co-vinyl acetate).

Claims

1. A method for controlling the rate of release of a bioactive agent from a coating composition provided in vivo, the method comprising the steps of:

a) providing a composition comprising a bioactive agent in combination with a plurality of polymers, including a first polymer component selected from the group consisting of polyalkyl(meth)acrylates and aromatic poly(meth)acrylates, and a second polymer component comprising poly(ethylene-co-vinyl acetate), and

b) applying the coating composition under conditions of controlled humidity to provide a corresponding controlled bioactive agent release profile in vivo.

2. A method according to claim 1 wherein the aromatic poly(meth)acrylates are selected from the group consisting polyalkyl(meth)acrylates, polyaryl(meth)acrylates, polyaralkyl(meth)acrylates, and polyaryloxyalkyl(meth)acrylates, and the coating is provided upon a surface of an implanted medical device and humidity is controlled either by controlling the humidity at which the device is coated with the composition and/or by controlling the water content of the coating or coated composition itself.

3. A method according to claim 1 wherein the coating is provided upon a surface of an implanted medical device and comprises a plurality of coating compositions, each independently coated under conditions of controlled humidity.

4. A method according to claim 2 wherein the device is one that undergoes flexion and/or expansion in the course of implantation or use in vivo.

5. A method according to claim 1 wherein the first polymer component is selected from the group consisting of:

a) polyalkyl(meth)acrylates with alkyl chain lengths from 2 to 8 carbons,

b) polyaryl(meth)acrylates, polyaralkyl(meth)acrylates, and polyaryloxyalkyl(meth)acrylates with aryl groups having from 6 to 16 carbon atoms, the first polymer component having a weight average molecular weight of about 50 to about 900 kilodaltons.

6. A method according to claim 5 wherein the polyaryl(meth)acrylates are selected from the group consisting of poly-9-anthracenylmethacrylate, polychlorophenylacrylate, polymethacryloxy-2-hydroxybenzophenone, polymethacryloxybenzotriazole, polynaphthylacrylate, polynaphthylmethacrylate, poly-4-nitrophenylacrylate, polypentachloro(bromo, fluoro)acrylate and methacrylate, polyphenylacrylate and methacrylate, the polyaralkyl(meth)acrylates are selected from the group consisting of polybenzylacrylate and methacrylate, poly-2-phenethylacrylate and methacrylate, poly-1-pyrenylmethylmethacrylate, and the polyaryloxyalkyl(meth)acrylates are selected from the group consisting of polyphenoxyethylacrylate and methacrylate, polyethyleneglycolphenylether acrylates and methacrylates.

7. A method according to claim 2 wherein the composition is coated onto the device under relative humidity controlled at a level of between about 0% and about 95% relative humidity.

8. A method according to claim 5 wherein the second polymer component is selected from the group consisting of poly(ethylene-co-vinyl acetate) polymers having vinyl acetate concentrations of between about 8% and about 90% by weight.

9. A method according to claim 8 wherein the vinyl acetate concentrations are between about 20% and about 40% by weight.

10. A method according to claim 1 wherein the composition is provided in a form selected from the group of solution, emulsion, mixture, dispersion or blend.

11. A method according to claim 10 wherein the total combined concentrations of both polymers in the composition is between about 0.05% and about 70% by weight.

12. A method according to claim 10 wherein the first polymeric component has a weight average molecular weight of from about 100 kilodaltons to about 500 kilodaltons and the poly(ethylene-co-vinyl acetate) has a vinyl acetate content of from about 20% to about 40% by weight.

13. A method according to claim 12 wherein the first polymeric component has a weight average molecular weight of from about 200 kilodaltons to about 400 kilodaltons and the poly(ethylene-co-vinyl acetate) has a vinyl acetate content of from about 30% to about 34% by weight.

14. A method according to claim 1 wherein the bioactive agent is dissolved or suspended in the coating composition at a concentration of about 0.01% to about 90% by weight.

15. A method according to claim 14 wherein the bioactive agent is selected from the group consisting of thrombin inhibitors, antithrombogenic agents, thrombolytic agents, fibrinolytic agents, vasospasm inhibitors, calcium channel blockers, vasodilators, antihypertensive agents, antimicrobial agents, antibiotics, inhibitors of surface glycoprotein receptors, antiplatelet agents, antimitotics, microtubule inhibitors, anti secretory agents, actin inhibitors, remodeling inhibitors, antisense nucleotides, anti metabolites, antiproliferatives, anticancer chemotherapeutic agents, anti-inflammatory steroid or non-steroidal anti-inflammatory agents, immunosuppressive agents, growth hormone antagonists, growth factors, dopamine agonists, radiotherapeutic agents, peptides, proteins, enzymes, extracellular matrix components, inhibitors, free radical scavengers, chelators, antioxidants, anti polymerases, antiviral agents, photodynamic therapy agents, and gene therapy agents.

16. A method according to claim 5 wherein the bioactive agent is dissolved or suspended in a coating composition having first and second polymer components at a total concentration of about 0.01% to about 90% by weight.

17. A method according to claim 16 wherein the bioactive agent is selected from the group consisting of thrombin inhibitors, antithrombogenic agents, thrombolytic agents, fibrinolytic agents, vasospasm inhibitors, calcium channel blockers, vasodilators, antihypertensive agents, antimicrobial agents, antibiotics, inhibitors of surface glycoprotein receptors, antiplatelet agents, antimitotics, microtubule inhibitors, anti secretory agents, actin inhibitors, remodeling inhibitors, antisense nucleotides, anti metabolites, antiproliferatives, anticancer chemotherapeutic agents, anti-inflammatory steroid or non-steroidal anti-inflammatory agents, immunosuppressive agents, growth hormone antagonists, growth factors, dopamine agonists, radiotherapeutic agents, peptides, proteins, enzymes, extracellular matrix components, inhibitors, free radical scavengers, chelators, antioxidants, anti polymerases, antiviral agents, photodynamic therapy agents, and gene therapy agents.

18. A method according to claim 8 wherein the bioactive agent is dissolved or suspended in the coating composition at a concentration of about 0.01% to about 90% by weight.

19. A method according to claim 18 wherein the bioactive agent is selected from the group consisting of thrombin inhibitors, antithrombogenic agents, thrombolytic agents, fibrinolytic agents, vasospasm inhibitors, calcium channel blockers, vasodilators, antihypertensive agents, antimicrobial agents, antibiotics, inhibitors of surface glycoprotein receptors, antiplatelet agents, antimitotics, microtubule inhibitors, anti secretory agents, actin inhibitors, remodeling inhibitors, antisense nucleotides, anti metabolites, antiproliferatives, anticancer chemotherapeutic agents, anti-inflammatory steroid or non-steroidal anti-inflammatory agents, immunosuppressive agents, growth hormone antagonists, growth factors, dopamine agonists, radiotherapeutic agents, peptides, proteins, enzymes, extracellular matrix components, inhibitors, free radical scavengers, chelators, antioxidants, anti polymerases, antiviral agents, photodynamic therapy agents, and gene therapy agents.

20. A method according to claim 19 wherein the surface is provided by a device that comprises a catheter or stent.

22. A combination comprising a device coated with a composition according to the method of claim 1, the combination being adapted to provide controlled release of the bioactive agent when positioned in an aqueous environment.

23. A combination according to claim 22 wherein the device is an implantable medical device that that undergoes flexion and/or expansion in the course of implantation or use in vivo, and the surface is coated with a plurality of coating compositions, each independently coated under conditions of controlled humidity.

24. A combination according to claim 22 wherein the first polymer component is selected from the group consisting of:

a) polyalkyl(meth)acrylates with alkyl chain lengths from 2 to 8 carbons, b) polyaryl(meth)acrylates, polyaralkyl(meth)acrylates, and polyaryloxyalkyl(meth)acrylates with aryl groups having from 6 to 16 carbon atoms, the first polymer component having a weight average molecular weight of about 50 to about 900 kilodaltons,

and the second polymer component is selected from the group consisting of poly(ethylene-co-vinyl acetate) polymers having vinyl acetate concentrations of between about 8% and about 90% by weight.

25. A combination according to claim 22 wherein the coating is provided by a coating composition in the form of a one part system comprising bioactive agent, and first and second polymer components, and the total combined concentrations of both polymers in the coating composition is between about 0.05% and about 70% by weight, and the bioactive agent is dissolved or suspended in the coating composition at a concentration of about 0.01% to about 90% by weight.

26. A combination according to claim 25 wherein the total combined concentrations of both polymers in the coating composition is between about 0.25% and about 10% by weight.

27. A combination according to claim 23 wherein the device is selected from the group consisting of catheters and stents.

28. A combination according to claim 27 wherein the catheter is selected from the group consisting of urinary catheters and intravenous catheters.

29. A combination according to claim 22 wherein the weight of the coating attributable to the bioactive agent is in the range of about one microgram to about 10 mg of bioactive agent per cm² of the gross surface area of the device.

30. A combination according to claim 29 wherein the weight of the coating attributable to the bioactive agent is between about 0.01 mg and about 0.5 mg of bioactive agent per cm² of the gross surface area of the device, and the coating thickness of the composition is in the range of about 0.1 micrometers to about 100 micrometers.

31. A method of using a combination of claim 23, the method comprising the steps of a) implanting the device in vivo under conditions in which the device undergoes flexion or expansion by being bent by at least 45 degrees or more and/or expanded to more than twice its initial dimension, either in the course of its placement, or thereafter in the course of its use in vivo, and b) permitting the device to remain implanted and to release the bioactive agent in situ.

32. A method according to claim 31 wherein the first polymer component is selected from the group consisting of

a) polyalkyl(meth)acrylates with alkyl chain lengths from 2 to 8 carbons,

b) polyaryl(meth)acrylates, polyaralkyl(meth)acrylates, and polyaryloxyalkyl(meth)acrylates with aryl groups having from 6 to 16 carbon atoms, the first polymer component having a weight average molecular weight of about 50 to about 900 kilodaltons,

and the second polymer component is selected from the group consisting of poly(ethylene-co-vinyl acetate) polymers having vinyl acetate concentrations of between about 8% and about 90% by weight.

33. A method according to claim 32 wherein the weight of the coating attributable to the bioactive agent is between about 0.01 mg and about 0.5 mg of bioactive agent per cm² of the gross surface area of the device, and the coating thickness of the composition is in the range of about 0.1 micrometers to about 100 micrometers.

34. A method according to claim 33 wherein the device is selected from the group consisting of catheters and stents.

35. A system comprising a coated device combination according to claim 22 positioned in situ within a body.

36. A method according to one of claims 1, 15, 21, or 31 wherein the composition further comprises a solvent in which the polymers form a true solution.

37. A method according to one of claims 1, 15, 21, or 31 wherein the device comprises a biomaterial selected from the group consisting of acrylics, vinyls, nylons, polyurethanes, polycarbonates, polyamides, polysulfones, poly(ethylene terephthalate), polylactic acid, polyglycolic acid, polydimethylsiloxanes, and polyetheretherketones, natural organic materials, metals, ceramics, glass, silica, and sapphire.

38. A method according to claim 37 wherein the acrylics are selected from methyl acrylate, methyl methacrylate, hydroxyethyl methacrylate, hydroxyethyl acrylate, acrylic acid, methacrylic acid, glyceryl acrylate, glyceryl methacrylate, methacrylamide, and acrylamide, the vinyls are selected from ethylene, propylene, styrene, vinyl chloride, vinyl acetate, vinyl pyrrolidone, and vinylidene difluoride, the nylons are selected from polycaprolactam, polylauryl lactam, polyhexamethylene adipamide, and polyhexamethylene dodecanediamide, the organic materials are selected from human tissue, wood, cellulose, compressed carbon, and rubber, the metals are selected from titanium, stainless steel, cobalt chromium, gold, silver, copper, and platinum and their alloys, and the ceramics are selected from silicon nitride, silicon carbide, zirconia, and alumina, including combinations of such biomaterials.

39. A method according to one of claims 1, 15, 21, or 31 wherein the device is selected from the group consisting of vascular devices, orthopedic devices, dental devices, drug delivery devices, ophthalmic devices, glaucoma drain shunts, urological devices, synthetic prostheses, dialysis tubing and membranes, blood oxygenator tubing and membranes, blood bags, sutures, membranes, cell culture devices, chromatographic support materials, and biosensors.

40. A method according to claim 39 wherein the vascular devices are selected from grafts, stents, catheters, valves, artificial hearts, and heart assist devices, the orthopedic devices are selected from joint implants, fracture repair devices, and artificial tendons, the dental devices are selected from dental implants and fracture repair devices, and the urological devices are selected from penile, sphincter, urethral, bladder, and renal devices.

21. A method for selecting an optimal bioactive agent release rate from a coated composition on a device to be positioned in vivo, the method comprising the steps of:

a) providing a composition comprising a bioactive agent in combination with a plurality of polymers, including a first polymer component comprising at least one polymer selected from the group consisting of polyalkyl(meth)acrylates, polyaryl(meth)acrylates, polyaralkyl(meth)acrylates, and polyaryloxyalkyl(meth)acrylates, and a second polymer component comprising poly(ethylene-co-vinyl acetate), and

b) coating the composition on test device surfaces at a plurality of different humidity levels in order to provide corresponding release profiles, and evaluating the corresponding release profiles to determine a desired controlled humidity level.