Article comprising a microneedle and methods of use

1. A method of injecting a fluid into a body, comprising injecting a fluid through an article into a body, the article comprising:

a first side comprising a central cavity portion and a platform portion that projects from the first side and that is not coplanar with the central cavity portion;

a second side opposite the first side; and

at least three hollow microneedles extending from the platform portion in a first direction;

wherein the platform portion substantially surrounds the central cavity portion;

wherein the platform portion comprises an inner perimeter proximate the central cavity portion and an outer perimeter distal the central cavity portion;

wherein the at least three hollow microneedles each comprise a body that comprises:

an outer surface;

a base segment having a base and a first shape that is defined by a first section of the outer surface;

a tip segment having a tip and a second shape that is defined by a second section of the outer surface, wherein the second shape is distinct from the first shape;

a transition plane that delineates the base segment and the tip segment; and

a central axis;

wherein a first angle, defined by the central axis of each of the at least three hollow microneedles and a shortest line extending from the outer perimeter of the platform and through the transition plane of the microneedle, is less than about 50°.

2. The method of claim 1 , wherein a second angle, defined by the central axis and a shortest line extending from the inner perimeter and through the transition plane, is less than about 50°.

3. The method of claim 1 , wherein the transition plane is disposed about 500 μm to about 800 μm away from the platform portion when measured along the central axis.

4. The method of claim 1 , wherein the first side further comprises a microneedle-free peripheral portion extending laterally from at least a part of the outer perimeter of the platform portion, wherein the peripheral portion is canted away from the platform portion in a second direction opposite the first direction.

5. The method of claim 4 , wherein the article further comprises a side wall portion that extends from the platform portion or, the peripheral portion; wherein the sidewall portion extends substantially opposite the first direction.

6. The method of claim 1 , wherein the central cavity portion is a closed cavity portion.

7. The method of claim 1 , wherein the central cavity portion is a through-hole extending from the first side through the second side.

8. The method of claim 1 , wherein the platform is circinate.

9. The method of claim 1 , wherein the at least three hollow microneedles are disposed in a circinate arrangement.

10. The method of claim 1 , wherein a unitary body comprises the platform portion, the peripheral portion, and the central cavity portion.

11. The method of claim 1 , wherein at least one microneedle of the at least three hollow microneedles further comprises:

a base;

and wherein

the tip segment of the at least one microneedle further comprises

a first bevel face oriented diagonally with respect to the central axis and extending through at least 75% of the body diameter, a second bevel face oriented substantially perpendicular to the central axis and intersecting the first bevel face, a bevel opening defined by a first edge of the first bevel face and a second edge of the second bevel face; and wherein the at least one microneedle further comprises a hollow channel that extends axially into the body from the bevel opening.

12. The method of claim 1 , wherein

the tip segment of the at least one microneedle further comprises a beveled surface, and a bevel opening in the beveled surface; and wherein the at least one microneedle further comprises

a first channel that extends axially from the bevel opening through at least a portion of the elongated body, wherein the first channel has a first wall that is substantially aligned with the central axis; and

a second channel that extends radially from the first channel to the bevel opening, wherein the second channel has a second wall that is oriented substantially orthogonal to the central axis;

wherein the first channel and second channel merge to form the bevel opening.

13. The method of claim 1 , wherein at least one microneedle of the at least three microneedles comprises a hollow channel extending through the article from a first opening proximate the tip to a second opening in the second side of the article.

14. The method of claim 1 , wherein the article is operatively coupled to an actuator.

15. The method of claim 1 , wherein the body is an animal body.

16. The method of claim 1 , wherein the article further comprises a skin-contact adhesive layer in an annular configuration and wherein the method further comprises the step of contacting the skin-contact adhesive to a skin surface to secure the article to the skin surface.

17. The method of claim 1 , wherein injecting the fluid into a body comprises delivering a pharmaceutical composition comprising an active compound to the body.

18. A method of extracting fluid from a body, comprising extracting a fluid from a body into an article, the article comprising:

a first side comprising a central cavity portion and a platform portion that projects from the first side and that is not coplanar with the central cavity portion;

a second side opposite the first side; and

at least three hollow microneedles extending from the platform portion in a first direction;

wherein the platform portion substantially surrounds the central cavity portion;

wherein the platform portion comprises an inner perimeter proximate the central cavity portion and an outer perimeter distal the central cavity portion;

wherein the at least three hollow microneedles each comprise a body that comprises:

an outer surface;

a base segment having a base and a first shape that is defined by a first section of the outer surface;

a tip segment having a tip and a second shape that is defined by a second section of the outer surface, wherein the second shape is distinct from the first shape;

a transition plane that delineates the base segment and the tip segment; and

a central axis;

wherein a first angle, defined by the central axis of each of the at least three hollow microneedles and a shortest line extending from the outer perimeter of the platform and through the transition plane of the microneedle, is less than about 50°.

19. The method of claim 18 , wherein the article is operatively coupled to an actuator.

20. The method of claim 18 , wherein at least one microneedle of the at least three hollow microneedles further comprises:

a base;

and wherein

the tip segment of the at least one microneedle further comprises

a first bevel face oriented diagonally with respect to the central axis and extending through at least 75% of the body diameter, a second bevel face oriented substantially perpendicular to the central axis and intersecting the first bevel face, a bevel opening defined by a first edge of the first bevel face and a second edge of the second bevel face; and wherein the at least one microneedle further comprises a hollow channel that extends axially into the body from the bevel opening.

21. The method of claim 18 , wherein at least one microneedle of the at least three hollow microneedles comprises:

an elongated body having a central axis; and further wherein

the tip segment of the at least one microneedle further comprises a beveled surface, and a bevel opening in the beveled surface; and wherein the at least one microneedle further comprises

a first channel that extends axially from the bevel opening through at least a portion of the elongated body, wherein the first channel has a first wall that is substantially aligned with the central axis; and

a second channel that extends radially from the first channel to the bevel opening, wherein the second channel has a second wall that is oriented substantially orthogonal to the central axis;

wherein the first channel and second channel merge to form the bevel opening.