Microstructures for delivering a composition cutaneously to skin

• US 20060129174A1
• Filed: 02/09/2006
• Published: 06/15/2006
• Est. Priority Date: 10/16/2000
• Status: Active Grant

• Current Assignee: Corium, Inc.
• Original Assignee: Corium International, Inc.
• Inventors: Gartstein, Vladimir, Sherman, Faiz Feisal
• Granted Patent: US 8,216,190 B2
• Time in Patent Office: Days
• US Class Current: 606/186
• CPC Class Codes: A45D 26/0004 by abrasion
• CPC Class Codes: A61B 17/205 Vaccinating by means of needles or other puncturing devices
• CPC Class Codes: A61B 17/322 Skin grafting apparatus
• CPC Class Codes: A61B 17/54 Chiropodists' instruments , e.g. pedicure chiropractic devices A61H1/008
• CPC Class Codes: A61B 2017/00761 Removing layer of skin tissue, e.g. wrinkles, scars or cancerous tissue
• CPC Class Codes: A61B 2017/00765 Decreasing the barrier function of skin tissue by radiated energy, e.g. using ultrasound, using laser for skin perforation
• CPC Class Codes: A61B 2017/320008 Scrapers
• CPC Class Codes: A61M 2037/0023 Drug applicators using microneedles
• CPC Class Codes: A61M 2037/003 having a lumen
• CPC Class Codes: A61M 2037/0038 having a channel at the side surface
• CPC Class Codes: A61M 2037/0046 Solid microneedles
• CPC Class Codes: A61M 2037/0053 Methods for producing microneedles
• CPC Class Codes: A61M 37/0015 by using microneedles

Abstract

An improved method and apparatus is provided as a system to deliver a composition, preferably a medical or pharmaceutical composition or active, through the stratum corneum of skin, without introducing bleeding or damage to tissue, and absent pain or other trauma. The dimensions and shapes of the microelements are controlled so as to control the penetration depth into the skin. The microelements can be “hollow” such that passageways are created therethrough to allow the composition to flow from a chamber, through the microelements, and into the skin. Alternatively, the microelements can be “solid,” and the composition is applied directly to the skin just before or just after the microelements are applied to the skin surface to create the openings in the stratum corneum.

Claims

1. A method for reducing the barrier properties of skin, the method comprising:

(a) providing a microstructure having a substrate and a plurality of microelements that protrude from said substrate by at least one predetermined protrusion distance; and

(b) placing and rubbing the microstructure on skin, in which said rubbing motion occurs in a direction that is substantially parallel to a surface of said skin, and wherein said at least one predetermined protrusion distance is sufficient so that many of said plurality of microelements penetrate a stratum corneum layer of said skin.

2. The method as recited in claim 1, wherein said predetermined direction is one of:

(a) linear, or (b) arcuate.

3. The method as recited in claim 1, wherein a shape of said plurality of microelements comprises one of:

(a) a pyramid;

or (b) an open, topless box having three walls;

or (c) a longitudinal wedge;

or (d) a curved wedge;

or (e) an elongated triangle;

or (f) a segmented elongated triangle.

4. The method as recited in claim 1, further comprising:

providing a fluidic compound that flows through first passageways in said substrate, then along channels in walls of said microelements or through second passageways in said microelements, thereby both penetrating said skin and delivering said fluidic compound to said skin in a single procedure.

5. The method as recited in claim 4, further comprising:

attaching said microstructure to said skin, after the stratum corneum has been penetrated during said rubbing step, to provide a protracted delivery of said fluidic compound.

6. The method as recited in claim 4, wherein a shape of at least some of said plurality of microelements and their adjacent substrate comprises one of:

(a) a pyramid having at least one channel along a wall of said pyramid, and at least one passageway in said substrate proximal to the wall of said pyramid, said channel being in fluidic communication with said passageway;

or

(b) an open, topless box having three walls, and at least one passageway in said substrate proximal to one of said three walls;

or

(c) a longitudinal wedge having at least one passageway therethrough which is in fluidic communication with at least one other passageway in said substrate;

or

(d) a curved wedge having at least one passageway therethrough which is in fluidic communication with at least one other passageway in said substrate;

or

(e) an elongated triangle having at least one channel along a wall of said elongated triangle, and at least one passageway in said substrate proximal to the wall of said elongated triangle, said channel being in fluidic communication with said passageway.

7. The method as recited in claim 4, further comprising:

(a) providing at least one chamber that holds said fluidic compound on a distal side of said substrate, wherein said distal side is opposite of a proximal side of said substrate upon which said microelements are formed; and

(b) delivering at least one said fluidic compound from said chamber through said at least one passageway in said substrate onto said skin.

8. The method as recited in claim 7, wherein said delivering step utilizes either iontophoresis or a pressure source.

9. The method as recited in claim 1, further comprising:

providing a fluidic compound on a same surface of said microstructure which contains said microelements, wherein said fluidic compound is at least in part applied into substantially a same area of said skin during said rubbing step.

10. The method as recited in claim 1, further comprising:

providing a backing layer that is impregnated with a fluidic compound and thereby acts as a fluid reservoir for use with said substrate which contains at least one passageway and which allows said fluidic compound to flow therethrough from said backing layer.

11. The method as recited in claim 1, further comprising:

withdrawing a biological fluid from skin by causing said biological fluid to flow then along channels in walls of said microelements or through first passageways in said microelements, then through second passageways in said substrate, thereby both penetrating said skin and sampling said biological fluid from the skin in a single procedure.

12. The method as recited in claim 11, wherein a shape of at least some of said plurality of microelements and their adjacent substrate comprises one of:

(a) a pyramid having at least one channel along a wall of said pyramid, and at least one passageway in said substrate proximal to the wall of said pyramid, said channel being in fluidic communication with said passageway;

or

(b) an open, topless box having three walls, and at least one passageway in said substrate proximal to one of said three walls;

or

(c) a longitudinal wedge having at least one passageway therethrough which is in fluidic communication with at least one other passageway in said substrate;

or

(d) a curved wedge having at least one passageway therethrough which is in fluidic communication with at least one other passageway in said substrate;

or

(e) an elongated triangle having at least one channel along a wall of said elongated triangle, and at least one passageway in said substrate proximal to the wall of said elongated triangle, said channel being in fluidic communication with said passageway.

13. The method as recited in claim 11, further comprising:

providing at least one chamber that receives said biological fluid on a distal side of said substrate, wherein said distal side is opposite of a proximal side of said microelements are formed.

14. The method as recited in claim 1, further comprising:

after said step of withdrawing the microstructure from the skin, manually applying a fluidic compound to substantially a same area of said skin.

15. The method as recited in claim 1, further comprising:

providing a fluidic compound on a same surface of said microstructure which contains said microelements, wherein said fluidic compound is at least in part applied to substantially a same area of said skin during said rubbing step.

16. The method as recited in claim 1, wherein said plurality of microelements exhibit at least one predetermined width, and wherein a healing time of said skin corresponds to a combination of said at least one predetermined protrusion distance and said at least one predetermined width.

17. A microstructure apparatus comprising a substrate and a plurality of microelements affixed to said substrate and extending outwardly therefrom, said microelements being adapted to penetrate a stratum corneum layer of the skin when said microstructure apparatus is placed in contact therewith, said microelements having a proximal end joined to said substrate and a distal end remote from said proximal end, at least some of said microelements comprising an external channel thereon, said external channel extending from said proximal end towards said distal end of said microelement, and being in fluidic communication with said substrate.

18. A microstructure apparatus according to claim 17, wherein said microelement tapers from said proximal end toward said distal end.