# US 10,441,532 B2 · Method of producing transdermal absorption sheet > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,441,532 B2 - Document ID: US10441532B2 - Status: Granted - Kind: B2 - Application number: 15/600,797 - Filed: 2017-05-22 - Published: 2017-11-23 - Granted: 2019-10-15 - Earliest claimed: 2016-05-23 - Assignees: FUJIFILM Corporation - Applicants: FUJIFILM Corporation - Inventors: Satoshi Wakamatsu - Web page: https://patentgrep.com/patent/US10441532B2 ## CPC - A61K 9/0021: {Intradermal administration, e.g. through microneedle arrays or needleless injectors} - A61K 47/36: Polysaccharides; Derivatives thereof, e.g. gums, starch, alginate, dextrin, hyaluronic acid, chitosan, inulin, agar or pectin - A61K 47/38: Cellulose; Derivatives thereof - A61M 37/0015: {by using microneedles} - B29C 39/24: Feeding the material into the mould - A61K 9/7007: {Drug-containing films, membranes or sheets (A61K9/0041, A61K9/0043, A61K9/006, A61K9/0063 take precedence)} - A61M 2037/0053: {Methods for producing microneedles} - B29D 7/01: Films or sheets - B29L 2031/7544: {Injection needles, syringes} - 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) - 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)} - B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00) - B29D: PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE (making granules B29B9/00; making preforms B29B11/00) - B29L: INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES ## Abstract A method of producing a transdermal absorption sheet includes: filling needle-like recessed portions on a mold having the needle-like recessed portions with a polymer solution; drying the filled polymer solution to form a polymer layer; and peeling off the polymer layer, wherein, in drying the polymer solution, low rate drying conditions are set in a concentration range in which an average solid content concentration of the polymer solution is 70 wt % to 80 wt %. When a constant drying rate of water is used as an index, in the concentration range in which the average solid content concentration of the polymer solution is 70 wt % to 80 wt %, and the constant drying rate is lower than a maximum value of a constant drying rate under a drying condition where the average solid content concentration of the polymer solution is less than 70 wt % and more than 80 wt %. ## Claims ### Claim 1 A method of producing a transdermal absorption sheet comprising, in this order: a polymer solution filling step of filling needle-like recessed portions on a mold having the needle-like recessed portions arranged two-dimensionally with a polymer solution; a polymer solution drying step of drying the polymer solution filling the needle-like recessed portions to form a polymer layer; and a peeling-off step of peeling off the polymer layer from the mold, wherein in the polymer solution drying step, low rate drying conditions are set in a concentration range in which an average solid content concentration of the polymer solution is 70 wt % or more and 80 wt % or less in terms of weight percent, and when a constant drying rate of water is used as an index, in the concentration range in which the average solid content concentration of the polymer solution is 70 wt % or more and 80 wt % or less in terms of weight percent, the constant drying rate is set to be lower than a maximum value of a constant drying rate under drying conditions in a concentration range in which the average solid content concentration of the polymer solution is less than 70 wt % and also set to be lower than a maximum value of a constant drying rate under drying conditions in a concentration range in which the average solid content concentration of the polymer solution is more than 80 wt % in terms of weight percent, and wherein the constant drying rate of water under the low rate drying conditions in the concentration range in which the average solid content concentration of the polymer solution is 70 wt % or more and 80 wt % or less in terms of weight percent is 0.10 kg/(h·m2) or less. ### Claim 2 (depends on 1) The method of producing a transdermal absorption sheet according to claim 1, wherein in the concentration range in which the average solid content concentration of the polymer solution is 70 wt % or more and 80 wt % or less in terms of weight percent, a lid having an opening portion is placed at a position where the lid covers the polymer solution. ### Claim 3 (depends on 1) The method of producing a transdermal absorption sheet according to claim 1, further comprising a drug solution filling step of filling the needle-like recessed portions with a drug-containing solution before the polymer solution filling step. ### Claim 4 (depends on 3) The method of producing a transdermal absorption sheet according to claim 3, further comprising a drug solution drying step of drying the drug-containing solution after the drug solution filling step before the polymer solution filling step. ### Claim 5 (depends on 1) The method of producing a transdermal absorption sheet according to claim 1, wherein the polymer solution contains a drug. ### Claim 6 (depends on 1) The method of producing a transdermal absorption sheet according to claim 1, wherein the constant drying rate in at least part of the concentration range in which the average solid content concentration of the polymer solution is less than 70 wt % in terms of weight percent is set to be higher than the constant drying rate in the concentration range in which the average solid content concentration of the polymer solution is 70 wt % or more and 80 wt % or less in terms of weight percent. ### Claim 7 (depends on 1) The method of producing a transdermal absorption sheet according to claim 1, wherein the constant drying rate in at least part of the concentration range in which the average solid content concentration of the polymer solution is more than 80 wt % in terms of weight percent is set to be higher than the constant drying rate in the concentration range in which the average solid content concentration of the polymer solution is 70 wt % or more and 80 wt % or less in terms of weight percent. ### Claim 8 (depends on 1) The method of producing a transdermal absorption sheet according to claim 1, wherein a polymer contained in the polymer solution includes at least one of sodium chondroitin sulfate, hydroxypropyl cellulose, or dextran. ### Claim 9 (depends on 1) The method of producing a transdermal absorption sheet according to claim 1, wherein a sheet portion average thickness after the polymer solution drying step is 50 μm or more and 500 μm or less.