Variable diameter cannula and methods for controlling insertion depth for medicament delivery

• US 9,956,114 B2
• Filed: 12/19/2016
• Issued: 05/01/2018
• Est. Priority Date: 06/20/2014
• Status: Active Grant

• Current Assignee: Clearside Biomedical, Inc.
• Original Assignee: Clearside Biomedical, Inc.
• Inventors: Andino, Rafael Victor, Brooks, Christopher John, Zarnitsyn, Vladimir, White, Harrison J.
• Primary Examiner(s): STIGELL, THEODORE J
• Application Number:
  US15/383,582
• Publication Number:
  US 20170095369A1
• Time in Patent Office: 498 Days
• CPC Class Codes: A61F 9/0008 Introducing ophthalmic products into the ocular cavity or retaining products therein putting in contact lenses A61F9/0061; introducing or retaining media in cavities of the body in general A61M31/00
• CPC Class Codes: A61M 2037/0023 Drug applicators using microneedles
• CPC Class Codes: A61M 2210/0612 Eyes
• CPC Class Codes: A61M 37/0015 by using microneedles
• CPC Class Codes: A61M 5/3286 Needle tip design, e.g. for improved penetration
• CPC Class Codes: A61M 5/329 characterised by features of the needle shaft
• CPC Class Codes: A61M 5/3293 characterised by features of the needle hub
• CPC Class Codes: A61M 5/46 having means for controlling depth of insertion
• CPC Class Codes: A61P 27/02 Ophthalmic agents

Abstract

An apparatus includes a microneedle that defines a lumen therethrough. The microneedle has a proximal end portion a distal end portion and a hub portion between the proximal end portion and the distal end portion. The proximal end portion is configured to be coupled to a medicament container, such as, for example a syringe. The portion of the lumen within the proximal end portion has a first diameter. The distal end portion is configured to pierce a target tissue. The portion of the lumen within the distal end portion has a second diameter smaller than the first diameter. The hub portion includes a surface configured to contact the target tissue when the distal end portion is disposed with the target tissue.

Claims

1. A method, comprising:

inserting a distal end portion of a puncture member of a medical injector into a target tissue to define a delivery passageway within the target tissue and such that a distal end surface of a hub of the medical injector is in contact with a target surface of the target tissue, the distal end portion of the puncture member defining at least a portion of the delivery passageway before the distal end surface of the hub contacts the target surface;

exerting a force on an actuation rod of the medical injector when the distal end surface of the hub is in contact with the target surface, the force having a magnitude of less than a threshold value, the force produces movement of the actuation rod within a medicament container coupled to the medical injector and increases a length of the puncture member extending distally from the distal end surface of the hub when the distal end portion of the puncture member is disposed within a first region of the target tissue and the distal end surface of the hub is in contact with the target surface of the target tissue; and

conveying, in response to the exerting, a substance from the medicament container into the target tissue via the puncture member when the distal end portion of the puncture member is disposed within a second region of the target tissue.

2. The method of claim 1, wherein the force increases the length of the puncture member extending distally from the distal end surface of the hub when the distal end surface of the hub is in contact with the target surface such that the distal end portion of the puncture member is moved into the second region of the target tissue.

3. The method of claim 1, wherein movement of the puncture member relative to the distal end surface of the hub in response to the force is limited in response to the distal end portion of the puncture member being disposed within the second region of the target tissue and the distal end surface of the hub is in contact with the target surface of the target tissue.

4. The method of claim 1, wherein the force is sufficient to overcome a backpressure of the second region such that movement of the distal end portion of the puncture member relative to the hub is reduced and the substance is conveyed into the target tissue when the distal end portion of the puncture member moves from the first region to the second region.

5. The method of claim 1, wherein:

the threshold value is about 6N,

the target tissue is an eye, the target surface is any one of a conjunctiva of the eye or a sclera of the eye,

the second region includes at least one of a suprachoroidal space, a lower portion of the sclera, a choroid of the eye, a subretinal space of the eye, or a retina of the eye,

the substance being at least one of a VEGF, a VEGF inhibitor, a PDGFR inhibitor, or a combination thereof.

6. The method of claim 1, further comprising:

during the exerting the force, maintaining a force on the medical injector such that the hub forms a substantially fluid-tight seal with the target surface.

7. The method of claim 1, wherein:

the force is insufficient to convey the substance from the medicament container into the target tissue via the puncture member when the distal end portion of the puncture member is disposed within the first region of the target tissue.

8. The method of claim 1, wherein:

before and during the inserting the distal end portion of the puncture member extends distally from the distal end surface of the hub by a first distance,

during the conveying the distal end portion of the puncture member extends distally from the distal end surface of the hub by a second distance greater than the first distance.

9. The method of claim 1, wherein:

the force increases the length of the puncture member extending distally from the distal end surface of the hub to create or expand the second region.

10. A method, comprising:

inserting a distal end portion of a puncture member of a medical injector into a sclera of an eye to define a delivery passageway within the eye;

exerting a force on an actuation rod of the medical injector when a surface of the medical injector is in contact with a conjunctiva of the eye or the sclera of the eye and the distal end portion of the puncture member is in the sclera the force having a magnitude of less than about 6N, the force (1) produces movement of the actuation rod within a medicament container coupled to the medical injector, and (2) increases a length of the puncture member extending distally from the surface of the medical injector to at least one of create or increase a suprachoroidal space or a subretinal space;

during the exerting the force on the actuation rod, maintaining a force on the medical injector such that the surface of the medical injector forms a substantially fluid-tight seal with the conjunctiva of the eye or the sclera of the eye; and

conveying, in response to the exerting, a substance from the medicament container into the suprachoroidal space or the subretinal space via the puncture member when the distal end portion of the puncture member is disposed within the suprachoroidal space or the subretinal space.

11. The method of claim 10, wherein the force increases the length of the puncture member extending distally from the surface of the medical injector when the surface of the medical injector is in contact with the conjunctiva of the eye or the sclera of the eye such that the distal end portion of the puncture member is moved into the second region of the eye.

12. The method of claim 10, wherein movement of the puncture member relative to the surface of the medical injector in response to the force is limited when the distal end portion of the puncture member is disposed within the second region of the eye and the surface of the medical injector is in contact with the conjunctiva of the eye or the sclera of the eye.

13. The method of claim 10, wherein the force is sufficient to overcome a backpressure of the second region such that movement of the distal end portion of the puncture member relative to the surface of the medical injector is reduced and the substance is conveyed into the eye when the distal end portion of the puncture member moves from the first region to the second region.

14. The method of claim 10, wherein the second region includes at least one of a suprachoroidal space, a lower portion of the sclera, a choroid of the eye, a subretinal space of the eye, or a retina of the eye.

15. The method of claim 10, wherein the substance is at least one of a VEGF, a VEGF inhibitor, a PDGFR inhibitor, or a combination thereof.

16. The method of claim 10, wherein the first region is an upper portion of the sclera of the eye.

17. The method of claim 10, wherein the inserting includes deforming the conjunctiva of the eye or the sclera of the eye with the surface of the medical injector.

18. The method of claim 10, wherein the inserting is performed when the exerting is performed.

19. The method of claim 10, wherein the exerting the force on the actuation rod of the medical injector includes exerting the force without causing the puncture member to contact a vitreous of the eye.

20. The method of claim 10, wherein the inserting, exerting, maintaining, and conveying are performed without contacting with the puncture member a vitreous body of the eye.

21. A method, comprising:

with a distal end portion of a puncture member of a medical injector extending distally by a first distance from a distal end surface of the medical injector, inserting the distal end portion of the puncture member into a first region of an eye to define a delivery passageway within the eye;

with the distal end portion of the puncture member disposed in the first region, exerting a force on an actuation rod of the medical injector, the force produces movement of the actuation rod within a medicament container coupled to the medical injector and causes the distal end portion of the puncture member to move relative to the medical injector such that (1) the puncture member extends distally by a second distance from the distal end surface of the medical injector and (2) the distal end portion of the puncture member is moved into a second region of the eye, the second distance being greater than the first distance; and

conveying, in response to the exerting, a substance from the medicament container into the second region via the puncture member when the distal end portion of the puncture member is disposed within the second region such that the medicament flows from the second region to a posterior segment of the eye, both the first region and the second region being in an anterior segment of the eye.

22. The method of claim 21, wherein the distal end portion of the puncture member extends distally by the first distance before and during the inserting.

24. The method of claim 21, wherein the force is sufficient to overcome a backpressure of the second region such that movement of the distal end portion of the puncture member relative to the distal end surface of the medical injector and the substance is conveyed into the second region when the distal end portion of the puncture member moves from the first region to the second region.

25. The method of claim 21, wherein:

the threshold value is about 6N,

the second region includes at least one of a suprachoroidal space, a lower portion of the sclera, a choroid of the eye, a subretinal space of the eye, or a retina of the eye,

the substance being at least one of a VEGF, a VEGF inhibitor, a PDGFR inhibitor, or a combination thereof.

26. The method of claim 21, wherein:

the force is insufficient to convey the substance from the medicament container into the eye via the puncture member when the distal end portion of the puncture member is disposed within the first region of the target tissue.

23. The method of 21, wherein movement of the puncture member relative to the distal end surface of the medical injector in response to the force is limited in response to the distal end portion of the puncture member being disposed within the second region of the eye.