Method of coating microneedle

• US 8,771,781 B2
• Filed: 10/18/2007
• Issued: 07/08/2014
• Est. Priority Date: 05/15/2007
• Status: Active Grant

• Current Assignee: Hisamitsu Pharmaceutical Company Incorporated
• Original Assignee: Hisamitsu Pharmaceutical Company Incorporated
• Inventors: Tokumoto, Seiji, Matsudo, Toshiyuki, Kuwahara, Tetsuji
• Primary Examiner(s): SELLMAN, CACHET I
• Application Number:
  US12/599,394
• Publication Number:
  US 20100280457A1
• Time in Patent Office: 2,455 Days
• Field of Search: None
• US Class Current: 427/2.1
• CPC Class Codes: A61K 9/0021 Intradermal administration, e.g. through microneedle arrays, needleless injectors mechanical aspects A61M
• CPC Class Codes: A61M 2037/0053 Methods for producing microneedles
• CPC Class Codes: A61M 37/0015 by using microneedles
• CPC Class Codes: B81B 2201/055 Microneedles
• CPC Class Codes: B81B 2203/0361 Tips, pillars
• CPC Class Codes: B81C 1/00206 Processes for functionalising a surface, e.g. provide the surface with specific mechanical, chemical or biological properties

Abstract

The present invention provides a method of coating microneedles by which the microneedles mounted on a microneedle device are coated accurately and easily in a mass-producible manner. In this method, a microneedle device (22) with a plurality of microneedles (21) is mounted on a table (23), while a mask plate (25) with a plurality of apertures (24) is fixed to a frame member (26), and a coating solution (27) is drawn in the direction of arrow A on the mask plate (25) using a spatula (28) to fill the apertures (24) with the coating solution. The microneedles (21) are inserted in the apertures (24) before or after the filling of the apertures (24) with the coating solution (27) to coat the microneedles (21).

Claims

1. A method of coating microneedles comprising the steps of:

filling a coating solution on a flat mask plate having blind holes as apertures arranged in rows and columns into the apertures using a spatula as a filling means so that the apertures are filled to capacity with the coating solution, and inserting microneedles of a microneedle device to the apertures filled with the coating solution to coat the microneedles.

2. The method of coating microneedles according to claim 1, wherein the steps are carried out at a relative humidity of 70.0 to 100% RH.

3. The method of coating microneedles according to claim 1, wherein the coating solution contains a carrier having a molecular weight of 1000 or more compatible with a physiologically active substance having a molecular weight of 1000 or more.

4. The method of coating microneedles according to claim 3, wherein the carrier having a molecular weight of 1000 or more is a polysaccharide.

5. The method of coating microneedles according to claim 4, wherein the polysaccharide is one or more selected from the group consisting of pullulan, hydroxypropylcellulose and hyaluronic acid.

6. The method of coating microneedles according to claim 1, wherein a coating amount to the microneedle is adjusted by changing at least one of

a. an opening diameter of the apertures formed on the mask plate,

b. a viscosity of the coating solution,

c. a clearance between the mask plate and the microneedle basal surface,

d. a spatula pressure,

e. a speed of spatula stroke,

f. a thickness of the mask plate, and

g. an attack angle between the spatula and the mask plate.

7. The method of coating microneedles according to claim 6, wherein an opening diameter of the apertures formed on the mask plate is in a range of 100 μ

m² to 90000 μ

m², which exceeds a cross sectional area of the microneedle at a lower end of the apertures when inserting the microneedle.

8. The method of coating microneedles according to claim 6, wherein a viscosity of the coating solution is in a range of 500 cps to 60000 cps.

9. The method of coating microneedles according to claim 6, wherein a clearance between the mask plate and the microneedle basal surface is in a range of 0 to 500 μ

m.

10. The method of coating microneedles according to claim 6, wherein a spatula pressure is in a range of 0.001 to 0.4 MPa.

11. The method of coating microneedles according to claim 6, wherein a thickness of the mask plate is in a range of 10 to 500 μ

m.

12. The method of coating microneedles according to claim 6, wherein an attack angle between the spatula and the mask plate is in a range of 65°

to 90°

.

13. The method of coating microneedles according to claim 6, wherein a speed of spatula stroke is in a range of 2 to 800 mm/sec.

14. A microneedle device comprising microneedles coated by the coating method of claim 1.