# US 8,771,781 B2 · Method of coating microneedle > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,771,781 B2 - Document ID: US8771781B2 - Status: Granted - Kind: B2 - Application number: 12/599,394 - Filed: 2007-10-18 - Published: 2010-11-04 - Granted: 2014-07-08 - Earliest claimed: 2007-05-15 - Assignees: Hisamitsu Pharmaceutical Co., Inc. - Applicants: Seiji Tokumoto; Toshiyuki Matsudo; Tetsuji Kuwahara - Inventors: Seiji Tokumoto; Toshiyuki Matsudo; Tetsuji Kuwahara - Web page: https://patentgrep.com/patent/US8771781B2 ## CPC - A61M 37/0015: {by using microneedles} - A61K 9/0021: {Intradermal administration, e.g. through microneedle arrays or needleless injectors} - B81C 1/00206: {Processes for functionalising a surface, e.g. provide the surface with specific mechanical, chemical or biological properties} - A61M 2037/0053: {Methods for producing microneedles} - B81B 2201/055: Microneedles - B81B 2203/0361: Tips, pillars - A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)} - A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D) - B81C: PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS (making microcapsules or microballoons B01J13/02; processes or apparatus specially adapted for the manufacture or treatment of piezoelectric, electrostrictive or magnetostrictive elements per se H10N30/01) - B81B: MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES (piezoelectric, electrostrictive or magnetostrictive elements per se H10N30/00, H10N35/00) ## 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 ### Claim 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. ### Claim 2 (depends on 1) 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. ### Claim 3 (depends on 1) 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. ### Claim 4 (depends on 3) The method of coating microneedles according to claim 3, wherein the carrier having a molecular weight of 1000 or more is a polysaccharide. ### Claim 5 (depends on 4) 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. ### Claim 6 (depends on 1) 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. ### Claim 7 (depends on 6) 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 μm2 to 90000 μm2, which exceeds a cross sectional area of the microneedle at a lower end of the apertures when inserting the microneedle. ### Claim 8 (depends on 6) 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. ### Claim 9 (depends on 6) 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 μm. ### Claim 10 (depends on 6) The method of coating microneedles according to claim 6, wherein a spatula pressure is in a range of 0.001 to 0.4 MPa. ### Claim 11 (depends on 6) The method of coating microneedles according to claim 6, wherein a thickness of the mask plate is in a range of 10 to 500 μm. ### Claim 12 (depends on 6) 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°. ### Claim 13 (depends on 6) 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. ### Claim 14 (depends on 1) A microneedle device comprising microneedles coated by the coating method of claim 1.