Biodegradable Poly(Ester-Amide) And Poly(Amide) Coatings For Implantable Medical Devices With Enhanced Bioabsorption Times
AssigneeAbbott Cardiovascular Systems Inc.
InventorsMICHAEL HUY NGO, Syed Faiyaz Ahmed Hossainy, Florencia Lim, O. Mikael Trollsas
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Abstract
This invention is generally related to coating layers for implantable medical devices, such as drug delivery vascular stents, and methods of fabricating coated implantable medical devices. Specifically various embodiments of the present invention include methods of fabricating and modulating of coating layers to enhance bioabsorption. The coating layers include poly(ester-amide) and/or poly(amide) polymers.
Claims20
A method of modulating the in vivo absorption rate of a coating on an implantable medical device comprising a poly(ester-amide) (PEA), a poly(amide) (PA) polymer, or a combination thereof, and a drug, the coating layer comprising a polymer phase and a dispersed drug phase, the method comprising:
- a) causing faster and greater water ingress into the coating layer,
- b) increasing fraction of interfacial area of the polymer with the dispersed drug phase, and/or
- c) increasing the surface area of the coating layer or the interfacial area of the polymer phase with the dispersed drug phase;
- wherein the coating layer completely degrades or substantially degrades within 12 months after implantation of the implantable medical device;
- wherein increasing the fraction of interfacial area of the polymer with the dispersed drug phase comprises using a soluble component to polymer ratio in the range of about 1:1 to about 1:7;
- and
- wherein the soluble component comprises a non-therapeutic component, or a non-therapeutic component and the drug.
(canceled)
A method of fabricating an implantable medical device coated with a bioabsorbable coating layer, the method comprising:
- applying to an implantable medical device a coating layer comprising a poly(ester-amide) and/or a poly(amide) polymer, and a soluble component;
- wherein the soluble component to polymer ratio is between 1:1 to 1:7;
- and
- wherein the coating layer thickness is between about 2 μm and 10 μm;
- and
- wherein the polymer in the coating layer, or the coating layer, is substantially absorbed or completely absorbed in vivo in 12 months or fewer after implantation.
A coating layer on a substrate, the coating layer comprising:
- a drug and a poly(ester-amide) polymer and/or a poly(amide) polymer wherein the ratio of drug to polymer is from about 1:3 to about 1:5;
- wherein the coating layer thickness on the substrate is between 2 μm to about 10 μm;
- and
- wherein the polymer mass in the coating layer after 3 months is about 50% or less of the initial polymer mass in the coating layer wherein the reduction is due to in vivo absorption.
A method of fabricating an implantable medical device coated with a bioabsorbable coating layer, the method comprising:
- providing an implantable medical device;
- applying to the implantable medical device a coating layer comprising a poly(ester-amide) and/or a poly(amide) polymer, and a soluble component;
- wherein the soluble component to polymer ratio is between 1:1 to 1:7;
- and
- wherein the coating layer thickness is between about 2 μm and 10 μm;
- determining the in vivo bioabsorption time of the coating layer;
- wherein if the in vivo bioabsorption time is too long:
- increasing the ratio of soluble component to polymer,
- decreasing the coating layer thickness, and/or
- decreasing the domain size of the soluble component;
- or if the in vivo bioabsorption time is too short:
- decreasing the ratio of soluble component to polymer,
- increasing the coating layer thickness, and/or
- increasing the domain size of the soluble component.
Dependencies are inferred from the claim text.