Micro-reservoir osmotic release systems and microtube array device

• US 7,534,241 B2
• Filed: 09/23/2003
• Issued: 05/19/2009
• Est. Priority Date: 09/23/2002
• Status: Expired due to Fees

• Current Assignee: Microchips Biotech, Inc. (Keratin Biosciences, Inc.)
• Original Assignee: MicroCHIPS Inc.
• Inventors: Coppeta, Jonathan R., Santini, John T. Jr., Uhland, Scott A.
• Primary Examiner(s): Sirmons; Kevin C
• Assistant Examiner(s): MOULTON, ELIZABETH ROSE
• Application Number:
  US10/668,573
• Publication Number:
  US 20040106914A1
• Time in Patent Office: 2,065 Days
• Field of Search: 6048901-8921, 604/93.01, 604/173
• US Class Current: 604/891.1
• CPC Class Codes: A61K 9/0004 Osmotic delivery systems; Sustained release driven by osmosis, thermal energy or gas
• 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 9/0097 Micromachined devices; Microelectromechanical systems [MEMS]; Devices obtained by lithographic treatment of silicon; Devices comprising chips intradermal microneedle arrays A61K9/0021; MEMS in general B81B7/02
• CPC Class Codes: A61M 2005/14513 with secondary fluid driving or regulating the infusion
• CPC Class Codes: A61M 2037/0023 Drug applicators using microneedles
• CPC Class Codes: A61M 2205/0244 Micromachined materials, e.g. made from silicon wafers, microelectromechanical systems [MEMS] or comprising nanotechnology
• CPC Class Codes: A61M 2205/0266 Shape memory materials
• CPC Class Codes: A61M 31/00 Devices for introducing or retaining media, e.g. remedies, in cavities of the body A61M25/00 takes precedence ; introducing or retaining ophthalmic products into the ocular cavities A61F9/0008
• CPC Class Codes: A61M 31/002 Devices for releasing a drug at a continuous and controlled rate for a prolonged period of time artificial gland structures or devices A61F2/022; intra-uterine contraceptive devices A61F6/14; tampons for introducing into the vagina A61F13/20, A61L15/00; suppositories or bougies for intra-vaginal or intra-uterine application A61K9/02; physical forms of medicinal preparations for sustained or differential drug release A61K9/20, A61K9/50
• CPC Class Codes: A61M 37/00 Other apparatus for introducing media into the body for reproduction or fertilisation A61B17/425; apparatus for iontophoresis or cataphoresis A61N1/30; Percutany, i.e. introducing medicines into the body by diffusion through the skin salt baths A61H33/04
• CPC Class Codes: A61M 37/0015 by using microneedles
• CPC Class Codes: A61M 5/141 with capillaries for restricting fluid flow
• CPC Class Codes: A61M 5/14276 specially adapted for implantation
• CPC Class Codes: A61M 5/14526 the piston being actuated by fluid pressure

Abstract

Devices and methods are provided for controlled release of chemical molecules, such as drugs. One device comprises a plurality of reservoirs; a rupturable covering, such as a thin metal film, enclosing a first end of each reservoir; a release formulation in each reservoir comprising chemical molecules for release; an expanding material layer in each reservoir; and a semi-permeable membrane enclosing a second end of each reservoir distal the release formulation, the semi-permeable membrane being operable to permit selected molecules (e.g., water) from outside the reservoir to diffuse to the expanding material layer to expand the expanding material layer and displace the release formulation in an amount effective rupture the rupturable membrane and discharge the release formulation. The device may further comprises a reservoir cap covering semi-permeable membrane and means for selectively disintegrating the reservoir cap to initiate diffusion of fluid molecules from outside the reservoir and through the semi-permeable membrane.

Claims

1. A device for the controlled release of chemical molecules comprising:

an array of discrete microtubes constructed of a metal or an alloy, each microtube comprising a reservoir defined therein;

a release formulation which comprises the chemical molecules, the release formulation being wholly contained in each reservoir;

a rupturable covering which closes an opening at a first end of each reservoir; and

a means for rupturing the rupturable covering and positively displacing the release formulation through the opening at the first end, to release the chemical molecules.

2. The device of claim 1, wherein the rupturable covering is provided with one or more defects to facilitate rupture.

3. The device of claim 1, wherein the means comprises a layer of an expanding material, and the release formulation is disposed between the layer of expanding material and the rupturable covering.

4. The device of claim 3, wherein a layer of a barrier material is disposed between the release formulation and the expanding material.

5. The device of claim 3, wherein the expanding material can be activated to expand upon application of heat.

6. The device of claim 1, wherein at least a portion of the array of discrete microtubes is constructed of a shape memory alloy.

7. The device of claim 1, wherein the release formulation is contained in a rigid substructure within the reservoir.

8. The device of claim 1, wherein the release formulation is a drug formulation.

9. The device of claim 1, wherein the rupturable covering comprises a metal foil.

10. The device of claim 1, wherein the microtubes are connected by and extend from a planar base.

11. The device of claim 10, wherein the microtubes and the planar base are constructed of a biocompatible metal.

12. The device of claim 11, wherein the biocompatible metal is selected from the group consisting of titanium, gold, platinum, Nitinol, and stainless steel.

13. The device of claim 10, wherein the microtubes are fused to the planar base by an electroplating process, an electroless plating process, or by a brazing process.

14. The device of claim 10, wherein the planar base is joined to a metal package, which together enclose control electronics for controlling the means for rupturing.

15. A method for the controlled delivery of chemical molecules, comprising:

placing the device of claim 1 at a site for release of the chemical molecules; and

activating the rupturing means to rupture the rupturable covering and release the chemical molecules at the site.

16. The method of claim 15, wherein the chemical molecules comprise a drug and the site is in vivo.

17. The device of claim 1, wherein each microtube has an inner diameter of between about 0.5 mm and 1.0 mm.

18. The device of claim 3, further comprising a semipermeable membrane enclosing a second end of each reservoir distal the rupturable covering, the semipermeable membrane being operable to permit selected molecules from outside the reservoir to diffuse to the expanding material to cause the expanding material to expand and displace the release formulation in an amount effective to rupture the rupturable covering and discharge the release formulation from the reservoir.

19. The device of claim 18, further comprising a reservoir cap, which covers the semi-permeable membrane, and a means for selectively disintegrating the reservoir cap.

20. The device of claim 5, wherein the means for rupturing comprises a reactive coating over at least a portion of the end of the microtube distal the rupturable covering.

21. A device for the controlled release of chemical molecules comprising:

an array of discrete microtubes, each microtube comprising a reservoir defined therein;

a release formulation which comprises the chemical molecules, the release formulation being disposed in each reservoir;

a rupturable covering enclosing a first end of each reservoir; and

a means for rupturing the rupturable covering and positively displacing the release formulation through an opening at the first end, to release the chemical molecules,

wherein the means for rupturing comprises a layer of an expanding material which can be activated to expand upon application of heat and a resistive heating element or resistive coating for heating the end of the microtube distal the rupturable covering upon application of an electric current through the resistive heating element or resistive coating, the release formulation being disposed between the layer of expanding material and the rupturable covering.

22. The device of claim 21, wherein the release formulation is a drug formulation.

23. The device of claim 21, wherein the rupturable covering comprises a metal foil.

24. The device of claim 21, wherein the rupturable covering is provided with one or more defects to facilitate rupture.

25. The device of claim 21, wherein the microtubes are constructed of titanium, gold, platinum, Nitinol, stainless steel, or another metal or alloy.

26. The device of claim 21, wherein the microtubes are connected by and extend from a planar base.

27. The device of claim 26, wherein the planar base is joined to a metal package, which together enclose control electronics for controlling the means for rupturing.