Tissue conforming microneedle array and patch for transdermal drug delivery or biological fluid collection

• US 7,785,301 B2
• Filed: 11/28/2006
• Issued: 08/31/2010
• Est. Priority Date: 11/28/2006
• Status: Active Grant

• Current Assignee: Vadim V. Yuzhakov
• Original Assignee: Vadim V. Yuzhakov
• Inventors: Yuzhakov, Vadim V
• Primary Examiner(s): Sirmons; Kevin C
• Assistant Examiner(s): Mehta; Bhisma
• Application Number:
  US11/563,892
• Publication Number:
  US 20080125743A1
• Time in Patent Office: 1,372 Days
• Field of Search: 604/46, 604/173, 604/180, 604/272, 604/506, 604/273, 604/274
• US Class Current: 604/272
• CPC Class Codes: A61M 2037/003 having a lumen
• CPC Class Codes: A61M 2037/0046 Solid microneedles
• CPC Class Codes: A61M 37/0015 by using microneedles
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

Microneedle arrays are provided for use on a contoured or flexible tissue surface. In one embodiment, the microneedle array includes a plurality of microneedles, each having a base portion, a tip end portion distal to the base portion, and body portion therebetween; and a flexible substrate which comprises a plurality of apertures, each of which are defined by (i) a plurality of substrate elements which are integral with the base portions of the microneedles, and (ii) at least one spring element connecting at least two of the substrate elements. The spring element may include a curved element, such as a C-shaped, U-shaped, or S-shaped element. Apertures may be defined, for example, by two substrate elements, which connected to three or four spring elements. A skin patch is provided for therapeutic or diagnostic applications, which includes the microneedle array and an adhesive material.

Claims

1. A microneedle array for use on a contoured or flexible tissue surface comprising:

a plurality of microneedles, each having a base portion, a tip end portion distal to the base portion, and a body portion between the base portion and the tip end portion; and

an elastically stretchable substrate which comprises a plurality of apertures, each of which are defined by both;

(i) a plurality of substrate elements which are integral with the base portions of the microneedles, and (ii) at least one spring element integral with and connecting at least two of the substrate elements,

wherein said at least one spring element is configured to allow the substrate to stretch when attached to and worn on the tissue surface.

2. The microneedle array of claim 1, wherein the spring element comprises a curved element.

3. The microneedle array of claim 2, wherein the curved element is C-shaped, U-shaped, or S-shaped.

4. The microneedle array of claim 1, wherein at least one of the apertures is defined by two substrate elements.

5. The microneedle array of claim 1, wherein each substrate element is connected to three or four spring elements.

6. The microneedle array of claim 1, wherein at least one of the plurality of microneedles has a channel extending substantially from the base portion through at least a part of the body portion, the channel being open along at least part of the body portion and in fluid communication with at least one of the apertures in the substrate.

7. The microneedle array of claim 6, wherein the base portion of the at least one of the microneedles is untapered and has a substantially rectangular cross-sectional shape in a plane parallel to the substrate.

8. The microneedle array of claim 7, wherein the at least one channel is open to two opposing surfaces of the microneedle.

9. The microneedle array of claim 6, wherein the tip end portion of the at least one of the microneedles is tapered.

10. The microneedle array of claim 9, wherein the at least one channel extends into the tapered tip end portion.

11. The microneedle array of claim 1, wherein the elastically stretchable substrate and the microneedles are formed of a biocompatible metal or polymer.

12. The microneedle array of claim 11, wherein the elastically stretchable substrate and the microneedles are formed of a biocompatible metal and the biocompatible metal comprises a stainless steel.

13. The microneedle array of claim 1, wherein the length of the plurality of microneedles is between 100 μ

m and 500 μ

m.

14. A skin patch for therapeutic or diagnostic applications comprising:

a microneedle array which comprises

a plurality of microneedles, each having (i) a base portion, a tip end portion distal to the base portion, and a body portion between the base portion and the tip end portion, and (ii) a channel extending substantially from the base portion through at least a part of the body portion, the channel being open along at least part of the body portion;

an elastically stretchable substrate which comprises a plurality of apertures, each of the apertures being defined by both;

(i) two or more substrate elements which are integral with the base portions of the microneedles, and (ii) at least one spring element integral with and connecting the two or more substrate elements,

wherein the channels of the microneedles are in fluid communication with at least one of the apertures in the substrate; and

an adhesive material for securing the microneedle array to a patient'"'"'s skin with the microneedles inserted into the stratum corneum,

wherein said at least one spring element is configured to allow the substrate to stretch when attached to and worn on the patient'"'"'s skin.

15. The skin patch of claim 14, wherein the spring element comprises a curved element.

16. The skin patch of claim 15, wherein the curved element is C-shaped, U-shaped, or S-shaped.

17. The skin patch of claim 14, wherein each substrate element is connected to three or four spring elements,

18. The skin patch of claim 14, wherein the base portion of at least one of the microneedles is untapered and has a substantially rectangular cross-sectional shape in a plane parallel to the substrate.

19. The skin patch of claim 18, wherein the at least one channel is open to two opposing surfaces of the microneedle.

20. The skin patch of claim 14, wherein the tip end portions of the microneedles are tapered.

21. The skin patch of claim 20, wherein the at least one channel extends into the tapered tip end portion.

22. The skin patch of claim 14, wherein the elastically stretchable substrate and the microneedles are formed of a biocompatible metal.

23. The skin patch of claim 14, wherein the elastically stretchable substrate and the microneedles are formed of a biocompatible polymer.

24. The skin patch of claim 14, further comprising a drug storage element for releasing a drug formulation to the patient'"'"'s skin.