Modular Drug Delivery System for Minimizing Trauma During and After Insertion of a Cochlear Lead

• US 20130041331A1
• Filed: 08/17/2012
• Published: 02/14/2013
• Est. Priority Date: 08/29/2007
• Status: Abandoned Application

• Current Assignee: Advanced Bionics LLC (Sonova Holding AG)
• Original Assignee: Advanced Bionics LLC (Sonova Holding AG)
• Inventors: Overstreet, Edward H., Xie, Jian, Colvin, Michael S., Faltys, Michael A.
• Application Number:
  US13/588,837
• Publication Number:
  US 20130041331A1
• Time in Patent Office: Days
• US Class Current: 604/285
• CPC Class Codes: A61K 2300/00 Mixtures or combinations of active ingredients, wherein at least one active ingredient is fully defined in groups A61K31/00 - A61K41/00
• CPC Class Codes: A61K 31/573 substituted in position 21, e.g. cortisone, dexamethasone, prednisone or aldosterone
• CPC Class Codes: A61K 45/06 Mixtures of active ingredients without chemical characterisation, e.g. antiphlogistics and cardiaca
• CPC Class Codes: A61K 9/0024 Solid, semi-solid or solidifying implants, which are implanted or injected in body tissue compositions for intravenous administration, normal injectable solutions or dispersions for, e.g. subcutaneous administration A61K9/0019; brain implants A61K9/0085; (coated) prostheses, catheters or stents A61L
• CPC Class Codes: A61K 9/0046 Ear
• CPC Class Codes: A61N 1/0541 Cochlear electrodes

Abstract

A system for delivering a therapeutic agent to biological tissue includes a surgically implantable lead to be inserted into the biological tissue. The surgically implantable lead includes a preformed cavity. A modular capsule is configured to be retained within the preformed cavity. The modular capsule includes a first therapeutic agent and a second therapeutic agent, wherein the first therapeutic agent elutes rapidly into the biological tissue and the second therapeutic agent elutes more slowly into the biological tissue.

Claims

1. A system for delivering a therapeutic agent to biological tissue comprising:

a surgically implantable lead configured to be inserted into the biological tissue, the surgically implantable lead comprising a preformed cavity; and

a modular capsule configured to be retained within the preformed cavity, the modular capsule comprising a first therapeutic agent and a second therapeutic agent, wherein the first therapeutic agent is configured to rapidly elute into the biological tissue and the second therapeutic agent is configured to more slowly elute into the biological tissue.

2. The system of claim 1, wherein the first therapeutic agent has a higher solubility in aqueous solutions than the second therapeutic agent.

3. The system of claim 1, wherein the first therapeutic agent comprises dexamethosone (DEX) salt and the second therapeutic agent comprises dexamethosone base (DXMb).

4. The system of claim 3, wherein the DEX salt elutes into a surrounding aqueous solution at higher concentrations than the DXMb.

5. The system of claim 1, further comprising a permeable membrane interposed between the biological tissue and therapeutic agents, wherein the first therapeutic agent in a first portion of the capsule has greater access to the membrane and elutes through the membrane in greater proportion than the second therapeutic agent placed in a second portion of the capsule with lesser access to the membrane.

6. The system of claim 5, wherein the permeable membrane comprises least one of porous polytetrafluoroethylene, a silicone membrane, fluorinated ethylene propylene, or cellulose acetate.

7. The system of claim 1, wherein at least one of the first therapeutic agent and the second therapeutic agent comprise microspheres.

8. The system of claim 1, wherein the first therapeutic agent comprises powered dexamethosone (DEX) salt having a first particle size and the second therapeutic agent comprises dexamethosone base (DXMb) having a second different particle size.

9. The system of claim 8, wherein the modular capsule further comprises a permeable membrane encapsulating the powered DEX salt and DXMb.

10. The system of claim 1, wherein the modular capsule comprises a polymer matrix and mixed DXMb and DEX salt particulates.

11. The system of claim 1, wherein the preformed cavity is covered by porous metal layer comprising a number of porous elution paths.

12. A system for delivering a therapeutic agent to biological tissue comprising:

a surgically implantable lead configured to be inserted into the biological tissue, the surgically implantable lead comprising a preformed cavity; and

a modular capsule configured to be retained within the preformed cavity, the modular capsule comprising a drug release profile when inserted in biological tissue, the drug release profile comprising a high initial concentration of a first therapeutic agent and a long term lower concentration of a second therapeutic agent.

13. A modular capsule for delivering a therapeutic agent to biological tissue, the modular capsule comprising:

a membrane;

a first portion comprising a first therapeutic agent; and

a second portion comprising a second therapeutic agent;

wherein the first portion has more direct access to the membrane than the second capsule such that the first therapeutic agent elutes through the membrane in greater proportion than the second therapeutic agent.

14. The capsule of claim 13, wherein the first therapeutic agent comprises dexamethosone (DEX) salt and the second therapeutic agent comprises dexamethosone base (DXMb).

15. The capsule of claim 13, wherein elution of the first therapeutic agent comprises a first particle size and the second therapeutic agent comprises a second particle size.

16. The capsule of claim 13, wherein the modular capsule comprises a solid tablet comprising DXMb and DEX salt.

17. The capsule of claim 13, wherein the capsule releases approximately 0.3 to 0.6 micrograms per day of DXMb into cochlear tissues.

18. The capsule of claim 13, wherein the membrane comprises polyvinyl alcohol (PVA) and walls of the capsule comprise silicone.