Microneedle comprising microfiber network structure
The present disclosure relates to a microneedle comprising a microfiber network structure, and more specifically, relates to a microneedle which comprises an insoluble microfiber network structure comprised in a substrate portion of a dissolving microneedle, so that it can deliver a large amount of an aqueous solution of drugs to skin through a hole for drug injection on the back side of a patch without including drugs in the microneedle, also regardless of drug types.
1 . A method of manufacturing a microneedle comprising:
i) first mixing a microneedle forming material with oxidized biocellulose microfibers;
ii) applying the mixture from (i) to a mold to form the microneedle, wherein the mold comprises a mold cavity to form a needle portion; and
iii) separating the microneedle formed in (ii) from the mold,
wherein the microneedle comprises the needle portion in which a plurality of needles are formed and a substrate portion to which the plurality of needles are attached,
wherein in i), the oxidized biocellulose microfibers are intertwined in three dimensions to form a microfiber network structure that cannot enter the mold cavity to form the needle portion,
wherein the substrate portion comprises the microfiber network structure,
wherein in ii), the microfiber network structure is comprised in the substrate portion and not comprised in the needle portion,
wherein some or all of alcohol groups of the oxidized biocellulose are substituted with carboxyl groups, and
wherein the method provides the microneedle in one casting step.
2 . The method according to claim 1 , wherein the microneedle forming material is swollen or dissolved in skin.
3 . The method according to claim 1 , wherein the microneedle forming material comprises a water-soluble polymer.
4 . The method according to claim 1 , wherein the microneedle forming material comprises one or more selected from the group consisting of hyaluronic acid or salts thereof, carboxymethyl cellulose or salts thereof, vinyl pyrrolidone-vinyl acetate copolymers, poly vinyl alcohols, poly vinyl pyrrolidone and sugars.
5 . The method according to claim 1 , wherein the content of the microfiber network structure comprised in the microneedle is 0.01% by weight or more, but less than 13.6% by weight based on the total weight of the microneedle.
6 . The method according to claim 1 , wherein a drug injection hole is formed in the substrate portion of the microneedle.
7 . The method according to claim 6 , wherein when a drug is injected through the drug injection hole, the injected drug is spread over the entire area of the microneedle patch by the microfiber network structure comprised in the substrate portion.
8 . The method according to claim 1 , wherein in the oxidized biocellulose, 0 . 8 mmol/g cellulose or more of cellulose among all alcohol groups comprised in the biocellulose before oxidation is substituted with a carboxyl group.