JP2016189845A - Microneedle sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a microneedle sheet capable of sufficiently administering moisture to the skin by causing the moisture supplied from a back face of the microneedle sheet to reach the skin, supplying a moisture content required for dissolving a microneedle to the microneedle, and sufficiently administering an object substance contained in the microneedle.SOLUTION: A microneedle sheet is configured so as to include a sheet-like base material that can be permeated with moisture, and a plurality of microneedles on one surface of the sheet-like base material.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a microneedle sheet for administering a target substance into the skin, and particularly to a microneedle sheet having a property that a sheet-like base material constituting the microneedle sheet allows moisture to pass through.

  A microneedle sheet has a plurality of microneedles arranged on a sheet-like substrate. A microneedle has a shape that hardly feels pain even when it is stabbed into the skin. By attaching the microneedle sheet to the skin, the microneedles stick into the skin, and a wide range of drugs can be administered.

  A soluble microneedle sheet that dissolves microneedles in the human body is composed of a target substance to be administered and a water-soluble material that is dissolved by moisture in the skin, such as dextran and hyaluronic acid, and moisture released from the skin. The When such a microneedle sheet is stabbed into the skin, the microneedles containing the target substance are swollen and dissolved by the moisture absorbed from the skin, and the target substance is delivered into the skin. Therefore, it is necessary to supply a sufficient amount of moisture to the microneedle sheet for dissolution.

  For such a problem, for example, Patent Document 1 discloses a technique in which the back surface of a microneedle sheet is covered with an adhesive tape in which holes are formed, and moisture is supplied from the back surface.

JP 2011-194189 A

  However, in the microneedle sheet disclosed in Patent Document 1, the penetration of the supplied moisture is inhibited by the adhesive tape and the sheet-like base material of the microneedle sheet, and the moisture does not reach the skin. There was a problem that it could not be administered sufficiently. In addition, since the supplied water does not reach the skin, the amount of water necessary for dissolution of the microneedles cannot be secured, and the target substance contained in the microneedles cannot be sufficiently administered.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a microneedle sheet that can sufficiently administer a target substance contained in a microneedle and water to be supplied.

  Hereinafter, a plurality of modes will be described as means for solving the problems. These embodiments can be arbitrarily combined as necessary.

  The microneedle sheet of the present invention is characterized by having a sheet-like base material having a property of passing moisture and a plurality of microneedles on one surface of the sheet-like base material.

  In a preferred embodiment, at least one through hole is formed in at least the sheet-like substrate.

  In a preferred embodiment, the thickness at the center of the sheet-like substrate is smaller than the thickness around the sheet-like substrate.

  In a preferred embodiment, the ratio of the area of the through hole to the area of the sheet-like substrate is 5 to 30%.

  In these preferred embodiments, a water supply layer containing an active ingredient is laminated on the other surface of the sheet-like substrate.

  In a preferred embodiment, the moisture supply layer is formed from a porous material.

  In a preferred embodiment, the moisture supply layer is any one of sponge, woven fabric, nonwoven fabric, absorbent cotton, and aqueous gel.

  The microneedle sheet according to the present invention is configured to have a sheet-like base material having a property of passing moisture and a plurality of microneedles on one surface of the sheet-like base material. Therefore, since the supplied water reaches the skin and the microneedles through the sheet-like base material, the target substance contained in the microneedles and the supplied water can be sufficiently administered.

It is sectional drawing of the microneedle sheet | seat which concerns on one Embodiment of this invention. It is sectional drawing of the microneedle sheet | seat which has a through-hole in a sheet-like base material. It is sectional drawing of the microneedle sheet | seat in which the center of a sheet-like base material is formed thinner than the circumference | surroundings. It is sectional drawing of the microneedle sheet | seat which concerns on the modification of embodiment of this invention. It is sectional drawing of the microneedle sheet | seat which has a water supply layer.

  The microneedle sheet of the present invention has a sheet-like substrate having a property of allowing moisture to pass through, and a plurality of microneedles on one surface of the sheet-like substrate. Hereinafter, an exemplary embodiment of the microneedle sheet of the present invention will be described.

<First embodiment>
First, a first embodiment according to the microneedle sheet of the present invention will be described with reference to the drawings.

  The microneedles 11 may be conical or pyramidal, for example, or may have another shape. The size is set, for example, in a range where the height is 10 μm to 1 mm, the maximum bottom width is 10 μm to 1 mm, and the aspect ratio is 0.5 to 4.

(Raw material of micro needle)
The raw material of the microneedles 11 is a polymer substance that is harmless to the human body, and includes, for example, a resin that is harmless to the human body, a polysaccharide that is harmless to the human body, a protein that is harmless to the human body, and a biologically active substance derived therefrom.

  The polymer substance that is harmless to the human body as the raw material of the microneedles 11 preferably has at least one of the properties of in vivo solubility and biodegradability. Here, the in vivo solubility is a property that dissolves in vivo, and the in vivo degradability is a property that decomposes in vivo. By forming the microneedles 11 with a polymer substance having at least one of both properties, the microneedles 11 that have entered the skin are subjected to the action of at least one of dissolution and decomposition in the living body, Since it gradually changes over time, it does not remain in the skin for a long time as a solid.

  In addition, the biosoluble and / or biodegradable polymer substance forming the microneedles 11 is preferably water-soluble. In the case of a water-soluble polymer substance, the microneedles 11 are dissolved by moisture in the skin, so that the target substance can be easily introduced into the skin using the microneedles 11.

  Examples of polysaccharides that are water-soluble and have at least one of in vivo solubility and biodegradability and are harmless to the human body and compounds derived therefrom are maltose, dextran, water-soluble chitosan, and pullulan. , Sodium chondroitin sulfate, sodium hyaluronate and glycogen. Examples of proteins harmless to the human body having at least one of water solubility, in vivo solubility and biodegradability and compounds harmless to the human body derived therefrom include serum albumin and serum α-acid glycoprotein. It is done. Examples of a resin that is at least one of water-soluble and in-vivo-soluble and biodegradable and harmless to the human body and compounds derived from it are biodegradable polymers that are harmless to the water-soluble human body. And compounds derived therefrom. Examples of biodegradable polymers that are harmless to the water-soluble human body and compounds that are harmless to the human body include carboxyvinyl polymers and polyethylene glycol (PEG), which is a water-soluble and biocompatible polymer, and lactic acid / glycolic acid. -A block polymer having water solubility and biodegradability obtained by block copolymerization of a copolymer (PLGA), polycaprolactone (PCL) or polylactic acid (PLA).

  Examples of the non-water-soluble resin having at least one of in vivo solubility and biodegradability are harmless to the human body and compounds derived from it are polylactic acid, polyglycolic acid, and the like. Polydioxanone may be mentioned.

  Note that the microneedle may be formed from at least one of the above materials. Further, at least two different raw materials may be formed in layers, or at least two different raw materials may be mixed and formed. The above raw materials can also be used as a target substance, and the microneedles 11 may be formed only from the target substance. For example, the microneedles 11 may be formed only from sodium hyaluronate.

(Water supplied)
Moisture is supplied from the surface of the microneedle sheet 10 opposite to the surface on which the microneedles 11 are formed. As the moisture, for example, cosmetics such as skin lotion, cosmetic liquid, and milky lotion may be used. Moreover, you may use the medicinal cosmetics containing the active ingredient which has the effect of preventing rough skin and acne, or the effect of whitening or deodorant. These can be supplied directly, alone or in combination.

(Sheet substrate)
The microneedle sheet of the present invention has a sheet-like substrate having a property of allowing moisture to pass through, and a plurality of microneedles on one surface of the sheet-like substrate. Therefore, the material of the sheet-like substrate has a property of passing moisture supplied from the surface opposite to the surface on which the microneedles 11 are formed. Examples of such a material include resins such as cellulose, polyurethane, polyethylene, and polyamide. These may be used after being processed into, for example, a woven fabric, a nonwoven fabric, or a film. Preferably, since the sheet-like base material and the microneedles can be integrally formed, the same material as the microneedles is used.

  The sheet-like substrate 12 is preferably processed with through holes (see FIG. 2). The through hole may be formed only in the sheet-like base material 12 or may be formed through a part of the sheet-like base material 12 and the microneedles 11. The shape of the through hole is not particularly limited, and may be a circular shape or a polygonal shape.

By processing the through-hole, the following effects can be obtained.
(1) Since moisture easily reaches the microneedles 11, the supplied moisture is absorbed by the microneedles together with moisture absorbed from the skin, and the microneedles that have absorbed moisture swell and easily dissolve. That is, the dissolution rate of the microneedles 11 can be increased.
(2) The supplied water can be accurately administered to the portion where the microneedle is stuck.

  The amount of water supplied to the microneedle sheet 10 through the through hole is determined by the ratio of the area of the through hole to the area of the sheet-like substrate 12, that is, the opening ratio. The aperture ratio is preferably 5 to 30%. If it is less than 5%, the amount of water supplied to the microneedle sheet 10 decreases, and it becomes difficult to efficiently administer the target substance contained in the microneedles 11 and the active ingredient contained in the supplied water. On the other hand, if it exceeds 30%, the strength of the sheet-like substrate 12 is reduced and the ratio of the through holes penetrating the microneedles 11 is increased, so that the dose of the target substance contained in the microneedles 11 is reduced. By adjusting the aperture ratio in this way, the supplied water can be efficiently delivered to the skin and the microneedles, and the active ingredient contained in the water and the target substance contained in the microneedles can be efficiently administered.

  The sheet-like base material 12 holds the microneedles 11. It is preferable that the thickness of the sheet-like base material 12 is 20-100 micrometers. If it is less than 20 μm, it is difficult to handle because it is thin, and the microneedle 11 is difficult to pierce the skin. On the other hand, if it exceeds 100 μm, it takes time for moisture supplied from the surface opposite to the surface on which the microneedles of the sheet-like substrate 12 are formed to reach the skin through the sheet-like substrate. Moreover, since the rigidity of a sheet | seat goes up, the followable | trackability to skin worsens.

  In the above embodiment, cosmetics and medicinal cosmetics have been described as examples of moisture, but the present invention is not limited thereto, and pharmaceuticals can also be used.

(Manufacturing method of microneedle sheet)
[When manufacturing microneedle and sheet-like substrate with the same material]
The microneedle sheet 10 can be integrally manufactured, for example, by pouring the material of the microneedles 11 into a mold in which the shape of the microneedle sheet 10 is carved and drying. If the target substance is a sheet made of sodium hyaluronate, for example, the microneedle sheet 10 may be formed using an aqueous solution of sodium hyaluronate as a main component. In addition, when the target substance is sodium hyaluronate and other physiologically active substances, the microneedle sheet 10 can be produced by pouring an aqueous solution of sodium hyaluronate added with other physiologically active substances into a mold and drying the mold. Good. Moreover, you may use methods other than the above as an addition method of another bioactive substance, for example, can also be added by apply | coating after drying. The microneedle sheet 10 can be manufactured by peeling the manufactured microneedle sheet 10 from the mold.

[When manufacturing microneedles and sheet-like substrate with different materials]
The microneedle sheet 10 is formed by, for example, pouring the material of the microneedles 11 into a mold in which the shape of the microneedles 11 is carved, and setting the sheet-like base material 12 on the mold. It can be manufactured by fixing and drying.

<Second embodiment>
Next, the microneedle sheet according to the second embodiment of the present invention will be described. The second embodiment differs from the first embodiment in that the thickness of the center of the sheet-like substrate 12 is smaller than the surrounding thickness (see FIG. 3).

  The same material as that of the first embodiment can be used as the material of the sheet-like base material 12, but the supplied water permeates through a portion having a small thickness, so that it has a property that it is difficult for moisture to pass through. It can be used even if it exists. Such materials include thermoplastic resins such as polyethylene, polypropylene, and polyethylene terephthalate.

  The part where the thickness of the sheet-like base material 12 is small should correspond to the region where the microneedles 11 are formed. In this way, the supplied water can be easily absorbed by the micro needle.

  In this microneedle sheet, since the thickness around the sheet-like base material is not changed and only the central thickness is small, the sheet-like base material is given flexibility while maintaining the strength of the sheet-like base material. The sheet can follow the skin well.

  In addition, the form in which thickness decreases partially may be sufficient by forming a some recessed part in the center of a sheet-like base material (refer FIG. 4). In such a microneedle sheet, the amount of water absorbed by the microneedle sheet can be easily adjusted by adjusting the number and depth of the recesses. Moreover, since the surface area of the center of the sheet-like base material 12 increases, when the sheet-like base material is the same water-soluble material as the microneedles, the dissolution rate of the sheet-like base material can be increased.

<Third embodiment>
Finally, a microneedle sheet according to a third embodiment of the present invention will be described. The third embodiment is different from the second embodiment in that a moisture supply layer is laminated on the surface of the sheet-like substrate 12 where the microneedles 11 are not formed (see FIG. 5).

  The moisture supply layer can have a size approximately equal to that of the sheet-like substrate 12 or a size that covers the sheet-like substrate 12.

  The moisture supply layer is formed by including the above-described cosmetic or medicinal cosmetic in a flexible porous material such as sponge, woven fabric, non-woven fabric, absorbent cotton, or aqueous gel. As the form of the moisture supply layer, the porous material containing moisture may be used as it is, or may be used in the form of a sheet mask or a pack. In such a microneedle sheet, moisture can be stably and continuously supplied to the microneedle sheet.

  In the third embodiment, for example, when the water supply layer protrudes from the sheet-like base material 12 in each direction, the microneedle can be obtained by applying an acrylic adhesive or the like to the outer edge portion of the protruded water supply layer. The sheet may be fixed to the skin. In addition, when the moisture supply layer is approximately the same size as the sheet-like base material, the microneedle sheet is stabbed into the skin and then wound with a bandage or the like, or a string-like member such as a string or rubber at both ends of the moisture supply layer May be attached to the body, or may be hooked.

  As described above, the microneedle sheet of the present invention can be obtained.

10: Microneedle sheet 11: Microneedle 12: Sheet-like base material 13: Water supply layer

Claims (7)

  A microneedle sheet comprising: a sheet-like base material having a property of allowing moisture to pass through; and a plurality of microneedles on one surface of the sheet-like base material.   The microneedle sheet according to claim 1, wherein at least one through hole is formed in at least the sheet-like base material.   The microneedle sheet according to claim 1, wherein the thickness of the center of the sheet-like substrate is smaller than the thickness around the sheet-like substrate.   The microneedle sheet according to claim 2, wherein a ratio of the area of the through hole to the area of the sheet-like substrate is 5 to 30%.   The microneedle sheet according to any one of claims 1 to 4, wherein a water supply layer containing an active ingredient is laminated on the other surface of the sheet-like substrate.   The microneedle sheet according to claim 5, wherein the moisture supply layer is formed of a porous material.   The microneedle sheet according to claim 5 or 6, wherein the moisture supply layer is one of sponge, woven fabric, nonwoven fabric, absorbent cotton, and aqueous gel.

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