Cochlear Implant Electrode Configuration for Drug Eluting

Abstract

A cochlear electrode array for electrically stimulating cochlear tissues including a drug eluting portion will be disclosed. This device is adapted to release over time a therapeutically effective amount of a pharmaceutical agent for the inner ear. The pharmaceutical agent can be released locally for different therapeutic applications.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A-F shows various ways to partially load an implanted cochlear electrode with drug eluting silicone.

FIG. 2A-D shows further various specific embodiments of a cochlear electrode with drug eluting silicone.

FIG. 3 shows an embodiment having drug eluting silicone and drug eluting silicone rod in a slot on the electrode.

FIG. 4A-B shows alternative embodiments for incorporating drug eluting silicone with the electrode.

Claims

1. A cochlear implant electrode array comprising: a cochlear electrode array for electrically stimulating cochlear tissue, the array including a drug eluting portion adapted to release over time a therapeutically effective amount of a pharmaceutical agent for the inner ear.

2. An electrode array according to claim 1, wherein the electrode array includes a slot containing a rod loaded with a pharmaceutical agent.

3. An electrode array according to claim 2, wherein the geometry of the slot determines the rate at which the pharmaceutical agent is released.

4. An electrode array according to claim 1, wherein the pharmaceutical agent is a gel, particulate or solid.

5. An electrode array according to claim 1, wherein the drug eluting portion is a polymer material incorporating the pharmaceutical agent.

6. An electrode array according to claim 5, wherein the polymer material is a silicon-based elastomer.

7. An electrode array according to claim 1, wherein the drug eluting portion is a layer of material sandwiched between two layers of non-drug eluting material.

8. An electrode array according to claim 7, wherein the drug eluting portion comprises 0.25% to 2% of the mass of the electrode array.

9. An electrode array according to claim 1, wherein the drug eluting portion is embedded within non-drug eluting material.

10. An electrode array according to claim 9, wherein the thickness of the non-drug eluting material determines the rate at which the pharmaceutical agent is released.

11. An electrode array according to claim 1, wherein the drug eluting portion begins at 3 mm or less from where the electrode array enters the inner ear.

12. An electrode array according to claim 1, wherein the release rate of the pharmaceutical agent is based on cross-link density of the material in the drug eluting portion.

13. An electrode array according to claim 1, wherein the release rate of the pharmaceutical agent is based on the amount of surface area of the drug eluting portion which is exposed to the fluid of the inner ear.

14. An electrode array according to claim 1, wherein the release rate of the pharmaceutical agent is based on the volume of the drug eluting portion.

15. An electrode array according to claim 1, wherein the drug eluting portion includes first and second drug eluting portions, each portion adapted to release a different pharmaceutical agent.

16. An electrode array according to claim 1, wherein the electrode array includes a plurality of electrical contacts for electrically stimulating the cochlear tissue, at least one of the contacts being coated with the pharmaceutical agent.

17. An electrode array according to claim 1, wherein the pharmaceutical agent is in the form of solid particles of less than 100 μm mixed into the material of the drug eluting portion.

18. An electrode array according to claim 1, wherein the release rate of the pharmaceutical agent is based on having particles of the pharmaceutical agent in a plurality of defined sizes.

19. An electrode array according to claim 18, wherein at least 90% of the particles are less than 50 μm.

20. An electrode array according to claim 18, wherein at least 50% of the particles are less than 10 μm.

21. An electrode array according to claim 1, wherein the pharmaceutical agent is a corticosteroid.

22. An electrode array according to claim 21, wherein the corticosteroid includes betamethasone, clobethasole, diflorasone, fluocinolone, triamcinolone, salt, ester, or combination thereof.

23. An electrode array according to claim 21, wherein the corticosteroid is dexamethasone.

24. An electrode array according to claim 23, wherein the electrode array is adapted to release between 0.1 and 1 μg of dexamethasone during an initial 24 hour period of use.

25. An electrode array according to claim 1, wherein the pharmaceutical agent is an anti-inflammatory agent.

26. An electrode array according to claim 25, wherein the saturated solubility in normal saline of the anti inflammatory agent is not less than 80 μg/ml at 37° C.

27. An electrode array according to claim 25, wherein the electrode array is adapted to release between 1 μg and 5 μg of anti inflammatory agent during the first week after implantation.

28. An electrode array according to claim 1, wherein the pharmaceutical agent is an antibiotic, antioxidant, or growth factor.