Microneedle device

Abstract

Reduce the labor of pre-moisturizing the skin and provide a new microneedle device. 【Solution means】A microneedle device 100 including an adhesive layer 1 and a microneedle sheet layer 10, wherein the adhesive layer 1 has one or more apertures 1a, and the microneedle sheet layer 10 has a substrate 2 and a plurality of microneedles 3 protruding from the substrate. The substrate 2 and the microneedles 3 are formed of a material that can dissolve or swell in vivo, and the microneedle sheet layer 10 is arranged so as to at least partially overlap the apertures 1a of the adhesive layer 1. Microneedle device 100.

Description

Technical Field

[0001] The present invention relates to a micro-needle device.

Background Art

[0002] Beauty technology has been continuously evolving day by day.

[0003] "Micro-needle technology" has been attracting attention in recent years as one of the beauty technologies. The micro-needle technology in the beauty industry is a technology that forms micro-needles by solidifying biodegradable components such as hyaluronic acid into micro-needle shapes and attaches them to the skin to allow components such as hyaluronic acid to penetrate the skin. More specifically, a micro-needle sheet containing micro-needles is adhered to the skin by, for example, an adhesive tape or the like, and the micro-needles penetrate the skin. Then, the moisture in the skin diffuses into the micro-needles, the needle portions inserted into the skin swell, and then dissolve. As a result, biodegradable components such as hyaluronic acid penetrate into the skin and exhibit a beauty effect.

[0004] In Patent Document 1, as a novel beauty method for improving blood circulation in the entire face and brightening the color tone of the entire face, a beauty method is disclosed in which a micro-needle sheet having a plurality of micro-needles is attached to a part of the face to brighten the color tone of the entire face.

[0005] Further, in Patent Document 2, as a micro-needle patch that is rapidly absorbed into the body and its usage method, a rapid dissolution method (excluding medical acts) of a micro-needle array is disclosed, which supplies moisture from the back of a micro-needle array having a substrate made mainly of a water-swellable polymer and having a thickness of 500 μm or less, and swells the micro-needle array with the moisture.

[0006] Note that Patent Document 3 discloses a method using an electrokinetic delivery system. More specifically, the method of Patent Document 3 is a method for delivering a drug to a treatment site under an electrically resistant layer of an individual's skin, comprising the steps of bringing a plurality of microneedles for penetrating the electrically resistant layer of the individual's skin into contact with the individual's skin, and electrokinetically driving the drug or the drug and an electrical carrier for the drug into the treatment site through the microneedles while bypassing the electrically resistant layer of the individual's skin.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0008] When applying microneedle technology, in order to penetrate beauty components or the like constituting the microneedle sheet layer (especially microneedles) into the skin, it is necessary to stably hold the microneedle sheet layer on the skin surface with its needle portion inserted into the skin. Usually, an adhesive layer such as an adhesive tape having a larger area than the area of the back surface (the surface opposite to the needles) of the microneedle sheet layer is placed on the back surface of the microneedle sheet layer, and the microneedle sheet layer is adhered to the skin surface with the adhesive force of the adhesive layer in a state where its needle portion is inserted into the skin.

[0009] However, when the entire back surface of the microneedle sheet layer is in close contact with the adhesive layer, depending on the constituent material of the adhesive layer, components leaching from the adhesive layer may affect the performance of the microneedle sheet layer. Therefore, there is room for improvement in the application of microneedle technology.

[0010] The present invention aims to improve the above circumstances, and its object is to provide a new microneedle device capable of suppressing the influence of the adhesive layer in contact with the back surface of the microneedle sheet layer on the performance of the microneedle sheet layer.

Means for Solving the Problems

[0011] The present invention for achieving the above object is as follows.

[0012] 〈Aspect 1〉 A microneedle device including an adhesive layer and a microneedle sheet layer, wherein the adhesive layer has one or more apertures, the microneedle sheet layer has a substrate and a plurality of microneedles protruding from the substrate, the substrate and the microneedles are formed of a material that can dissolve or swell in vivo, and the microneedle sheet layer is arranged so as to at least partially overlap the apertures of the adhesive layer, a microneedle device. 〈Aspect 2〉 The microneedle device according to Aspect 1, further including an electrode sheet layer on a surface of the adhesive layer opposite to the microneedles. 〈Aspect 3〉 The microneedle device according to Aspect 1 or 2, wherein the microneedle sheet layer is arranged so as to overlap the apertures of the adhesive layer or inside the apertures. 〈Aspect 4〉 Further including a support layer, wherein the support layer is arranged in the apertures of the adhesive layer, and The micro-needle sheet layer is supported by the support layer. The micro-needle device according to any one of Aspects 1 to 3. <Aspect 5> The micro-needle device according to any one of Aspects 1 to 4, wherein the material that can be dissolved or swollen in the living body is hyaluronic acid. <Aspect 6> The micro-needle device according to any one of Aspects 1 to 5, which is for skin care. <Aspect 7> A beauty method using the micro-needle device according to any one of Aspects 1 to 6, including permeating at least a part of the constituent material of the micro-needles into the skin by attaching and closely adhering the micro-needle side of the micro-needle device to the skin. Beauty method. <Aspect 8> A beauty method using the micro-needle device according to any one of Aspects 2 to 6, including permeating at least a part of the constituent material of the micro-needles into the skin by attaching and closely adhering the micro-needle side of the micro-needle device to the skin, and applying a pulsed current to the skin through the electrode sheet layer. including Beauty method. [Advantages of the Invention]

[0013] According to the present invention, it is possible to provide a new micro-needle device that reduces the labor of pre-moisturizing the skin and can efficiently dissolve the needle portions inserted into the skin. [Brief Description of the Drawings]

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0015] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. For convenience of explanation, in each figure, the same or corresponding parts are denoted by the same reference numerals, and duplicate explanations are omitted. Further, the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the gist of the invention.

[0016] 《Microneedle Device》 The microneedle device of the present invention is A microneedle device including an adhesive layer and a microneedle sheet layer, The adhesive layer has one or more apertures, The microneedle sheet layer has a substrate and a plurality of microneedles protruding from the substrate, The base material and the micro needles are made of a material that can be dissolved or swollen in vivo, and the micro needle sheet layer is arranged so as to at least partially overlap the apertures of the adhesive layer, a micro needle device is provided.

[0017] FIG. 1 is a schematic cross-sectional view showing an example of the micro needle device of the present invention.

[0018] The micro needle device 100 of the present invention shown in FIG. 1 includes an adhesive layer 1 and a micro needle sheet layer 10. In the micro needle device 100, the adhesive layer 1 has one or more apertures 1a. Further, the micro needle sheet layer 10 has a base material 2 and a plurality of micro needles 3 protruding from the base material. Further, as shown in FIG. 1, the micro needle sheet layer 10 is arranged so as to at least partially overlap the apertures 1a of the adhesive layer 1.

[0019] When the entire back surface of the micro needle sheet layer is in contact with the adhesive layer, depending on the constituent material of the adhesive layer, the components leaching from the adhesive layer may affect the performance of the micro needle sheet layer.

[0020] Specifically, for example, when a hydrogel layer with a high water content is used as the adhesive layer, the hydrogel layer retains the moisture of the skin and / or supplies moisture to the skin in addition to the role of attaching and holding the micro needle sheet layer to the skin, thereby promoting the swelling and / or dissolution of the material forming the micro needles in the skin. However, in such a case, if the entire back surface of the micro needle sheet layer is in contact with the adhesive layer, the moisture of the hydrogel layer may swell and / or dissolve the micro needle sheet layer before the micro needle sheet layer is attached to the skin.

[0021] On the other hand, according to the present invention, one or more apertures are provided in the adhesive layer, and the microneedle sheet layer at least partially overlaps with the apertures of the adhesive layer, thereby suppressing the components leaching from the adhesive layer, for example, the moisture leaching from the hydrogel layer as the adhesive layer, from affecting the performance of the microneedle sheet layer.

[0022] Hereinafter, each member that can constitute the microneedle device of the present invention will be described in detail.

[0023] 〈Adhesive layer〉 In the present invention, as the adhesive layer, for example, it may not cause pain when peeled off while having a holding force when adhered to the skin. The adhesive layer may be a layer provided by applying, impregnating, adhering, casting, etc. an adhesive component on one surface of the base material of the adhesive layer.

[0024] Here, the adhesive component is not particularly limited, and examples thereof include various water-soluble polymers, oil-soluble polymers, or gel agents obtained by partially modifying these by means such as crosslinking. More specifically, as the adhesive component, for example, it may be a hydrogel, but is not limited thereto.

[0025] The adhesive layer may contain a conductive material such as conductive particles, and thereby can have conductivity. Examples of such a conductive material such as conductive particles include carbon, graphite, carbon nanotubes, organic conductive substances such as PEDOT-PSS, and metals such as copper, aluminum, and silver. When the adhesive layer has conductivity, for example, by using it in combination with an electrode sheet layer described later, a pulsed current can be applied to the skin favorably.

[0026] As described above, when a hydrogel layer is used as the adhesive layer, the hydrogel layer, in addition to the role of adhering and holding the microneedle sheet layer to the skin, can retain the moisture of the skin and / or supply moisture to the skin, thereby promoting the swelling and / or dissolution in the skin of the material forming the microneedles.

[0027] In addition, since the hydrogel has conductivity, for example, when used in combination with an electrode sheet layer described later, the application of pulsed current to the skin can be performed favorably.

[0028] Hereinafter, an adhesive layer using the hydrogel will be exemplarily described.

[0029] (Hydrogel) In the present invention, a hydrogel is a general term for gel-like hydrophilic polymers containing water inside. More specifically, examples of hydrogels include gels containing natural polymers such as agar, gelatin, agarose, xanthan gum, gellan gum, schizophyllan gum, gum arabic, tragacanth gum, karaya gum, cellulose gum, tamarind gum, guar gum, locust bean gum, glucomannan, chitosan, carrageenan, quince seed, galactan, mannan, starch, dextrin, curdlan, casein, pectin, collagen, fibrin, peptide, chondroitin sulfate salts such as sodium chondroitin sulfate, hyaluronic acid (mucopolysaccharide), hyaluronate salts such as sodium hyaluronate, alginic acid, sodium alginate, and alginate salts such as calcium alginate, and derivatives thereof; gels containing cellulose derivatives such as methylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, carboxymethylcellulose, and salts thereof; gels containing poly(meth)acrylic acids such as polyacrylic acid, polymethacrylic acid, and alkyl copolymers of acrylic acid and methacrylic acid, and salts thereof; gels containing synthetic polymers such as polyvinyl alcohol, polyhydroxyethyl methacrylate, polyacrylamide, poly(N-isopropylacrylamide), polyvinylpyrrolidone, polystyrene sulfonic acid, polyethylene glycol, carboxyvinyl polymer, alkyl-modified carboxyvinyl polymer, maleic anhydride copolymer, polyalkylene oxide resin, crosslinked N-vinylacetamide, crosslinked acrylamide, and starch-acrylate graft copolymer crosslinked products; silicone hydrogels; interpenetrating network structure hydrogels and semi-interpenetrating network structure hydrogels; or mixtures of two or more of these, but not limited thereto.

[0030] (Base material of the adhesive layer) The base material of the adhesive layer is not particularly limited and may be, for example, a woven fabric, non-woven fabric, porous sheet, mesh, or film.

[0031] Further, as the base material of the adhesive layer, for example, the electrode sheet layer described later may be used. In this case, the adhesive layer can apply a pulsed current having a predetermined frequency to the skin, thereby enabling collagen production, moisturization, and wrinkle improvement of the skin.

[0032] (Opening of the Adhesive Layer) In the microneedle device of the present invention, the adhesive layer has one or more openings. The openings of the adhesive layer are for reducing the contact area between the microneedle sheet layer and the adhesive layer or for preventing contact between the microneedle sheet layer and the adhesive layer. Therefore, the number of openings is not particularly limited as long as it is one or more, and may be appropriately adjusted according to the area of the target microneedle device, the size of the microneedle sheet layer, etc.

[0033] For example, the adhesive layer may have one or more, two or more, three or more, four or more, or five or more openings, and may also have ten or fewer, nine or fewer, eight or fewer, seven or fewer, six or fewer, or five or fewer openings. Further, the shape of the openings is not particularly limited and may be appropriately adjusted according to the shape of the target microneedle device or the shape of the microneedle sheet layer. Furthermore, the size and position of the openings are not particularly limited and may be appropriately adjusted according to the area of the target microneedle device, the placement location of the microneedle sheet layer, etc.

[0034] FIG. 2 is a plan view showing some forms of an adhesive layer having one or more openings. More specifically, the adhesive layer 1A shown in FIG. 2(a) has one opening 1a. The adhesive layer 1B shown in FIG. 2(b) has two openings 1a and 1b. The adhesive layer 1C shown in FIG. 2(c) has three openings 1a, 1b, and 1c. The adhesive layer 1C shown in FIG. 2(d) has five openings 1a, 1b, 1c, 1d, and 1e. The adhesive layer 1E shown in FIG. 2(e) has three openings 1a, 1b, and 1c. As also shown in FIGS. 2(a) to 2(e), the number, shape, size, and position, etc. of the openings existing in the adhesive layer are not particularly limited.

[0035] (Water content) In the present invention, the water content of the hydrogel or the adhesive layer is not particularly limited. For example, it may be 0% by mass or more, 0.5% by mass or more, 1.0% by mass or more, 5.0% by mass or more, 10% by mass or more, 20% by mass or more, 30% by mass or more, 40% by mass or more, 50% by mass or more, 60% by mass or more, 70% by mass or more, or 80% by mass or more, and may also be 99% by mass or less, 95% by mass or less, or 90% by mass or less. The water content of the adhesive layer can be measured, for example, from the mass reduction rate associated with heat drying or vacuum drying. Further, the water content of the adhesive layer can be determined from the mass ratio of the adhesive component used and its water content.

[0036] (Thickness of the adhesive layer) Also, the thickness of the adhesive layer is not particularly limited and may be, for example, in the range of 1.0 μm to 10 mm.

[0037] (Area of the adhesive layer) The area of the adhesive layer is not particularly limited and can be appropriately set according to the purpose. For example, when the purpose is to apply the microneedle device to a part of the face, the area of the adhesive layer, when including the area of the apertures, may be, for example, 250 mm 2 or more, 500 mm 2 or more, or 1000 mm 2 or more, and may also be 5000 mm 2 or less, 4000 mm 2 or less, or 3000 mm 2 or less.

[0038] 〈Microneedle sheet layer〉 In the present invention, the microneedle sheet layer has a substrate and a plurality of microneedles protruding from the substrate.

[0039] The microneedle sheet layer according to the present invention is arranged so as to at least partially overlap with the apertures of the above-described adhesive layer. Further, from the viewpoint of preventing contact between the microneedle sheet layer and the adhesive layer, it is preferable that the microneedle sheet layer is arranged so as to overlap with the apertures of the adhesive layer or inside the apertures. When the microneedle sheet layer is arranged inside the apertures of the adhesive layer, from the viewpoint of preventing contact between the microneedle sheet layer and the adhesive layer, for example, an adhesive or the like may be arranged at a portion where the microneedle sheet layer and the adhesive layer can come into contact (for example, refer to the adhesive 6 in FIG. 7 described later). Further, even when the microneedle sheet layer is arranged so as to at least partially overlap with the apertures of the adhesive layer, similarly, an adhesive or the like may be arranged at a portion where the microneedle sheet layer and the adhesive layer can come into contact.

[0040] (Microneedle) The microneedles used in the present invention are formed of a material that can be dissolved or swollen in vivo. The material that can be dissolved or swollen in vivo used in the present invention may be any material that exhibits a certain degree of hardness so as to penetrate the skin and cause irritation, and the material itself is not particularly limited. Examples of such materials that can be dissolved or swollen in vivo include polysaccharides such as hyaluronic acid, chitosan, maltose, alginate, amylose, and agarose, celluloses such as carboxymethyl cellulose and hydroxypropyl cellulose, and starch, but are not limited thereto. Further, when forming the microneedles, these materials that can be dissolved or swollen in vivo may be used alone, or a mixture in which two or more kinds are appropriately blended may be used.

[0041] Among these materials, hyaluronic acid is particularly preferable. Hyaluronic acid is usually used in a salt state, and examples of the salt include metal salts such as sodium salt and potassium salt. As hyaluronic acid, for example, those having an average molecular weight of 10,000 or less to those having a high molecular weight of 800,000 or more measured by HPLC or the like can be used. Further, appropriately, a mixture of a low molecular weight hyaluronic acid and a high molecular weight hyaluronic acid can also be used.

[0042] In addition, water-soluble drugs and cosmetic ingredients that have been conventionally used as transdermal absorption preparations in microneedles, such as ascorbyl palmitate, kojic acid, lucinol, tranexamic acid, potassium 4-methoxysalicylate, pyrimidinyl pyrazole compounds, haksinin extract, oil-soluble licorice extract, whitening ingredients such as vitamin A derivatives; anti-wrinkle ingredients such as retinol, retinoic acid, retinol acetate, retinol palmitate; blood circulation promoting ingredients such as tocopherol acetate, capsaicin, vanillylamide nonylate; diet ingredients such as raspberry ketone, evening primrose extract, seaweed extract; antibacterial ingredients such as isopropylmethylphenol, photosensitizer, zinc oxide; medicinal ingredients such as vitamins such as vitamin D2, vitamin D3, vitamin K may be added.

[0043] In the present invention, the shape of the microneedle is not particularly limited, but a conical shape, a frustum of a cone shape, a conyde shape, etc. are preferable so that it is easy to pierce the skin and does not cause pain when piercing. The conyde shape is a shape called a so-called volcanic shape, and is a shape in which the side surface of the frustum of a cone is curved inward.

[0044] When the diameter of the base of the microneedle becomes thinner, it is likely to break when piercing the skin, and when it becomes thicker, it causes pain when piercing the skin, so about 0.15 to 1.0 mm, preferably about 0.15 to 0.5 mm is appropriate. When the tip diameter becomes thinner (sharper), it is likely to break when piercing the skin, and when it becomes thicker, it is difficult to pierce the skin and causes pain, so 0.01 to 0.2 mm is appropriate.

[0045] The height of the microneedle needs to be high enough to penetrate the skin and cause stimulation. However, if it is too high, there is a risk of reaching the skin basement membrane, and it may also be prone to breakage when penetrating the skin. Therefore, for example, a height of 50 μm to 1000 μm, preferably 100 to 800 μm, more preferably about 300 to 800 μm is appropriate. Also, the pitch between microneedles becomes difficult to penetrate the skin when it is short, and when it is long, the number of microneedles per unit area decreases, and the effect of the present invention may not be exhibited. Therefore, 0.3 to 1.0 mm is appropriate.

[0046] In addition, the number of microneedles in the microneedle sheet layer is not particularly limited. For example, per an area of 100 mm 2 it may be 10 to 3000.

[0047] (Base material of the microneedle sheet layer) In the present invention, the base material of the microneedle sheet layer may have the same material as the microneedle or a different material as long as it can form microneedles on its surface. From the viewpoint of more significantly expressing the effect of the present invention, the base material of the microneedle sheet layer is preferably a material that can dissolve or swell in the living body. Specific examples of the material that can dissolve or swell in the living body are the same as those in the above-mentioned item of "microneedle", and the description is omitted here.

[0048] The thickness of the base material of the microneedle sheet layer is not particularly limited and may be, for example, in the range of 0.01 mm to 2.0 mm.

[0049] (Area of the microneedle sheet layer) The area of the microneedle sheet layer is not particularly limited. However, from the viewpoint of exerting the fixing effect of the hydrogel layer, it can be appropriately set according to the purpose within a range smaller than the area of the above-mentioned hydrogel layer (when including the area of the opening). For example, when the purpose is to apply the microneedle device to a part of the face, the area of the microneedle sheet layer is, for example, 200 mm 2500 mm or more 2 or 1000 mm or more 2 and may be 5000 mm or less 2 4000 mm or less 2 or 3000 mm or less 2 and may be less than that.

[0050] 〈Electrode sheet layer〉 The microneedle device of the present invention preferably further includes an electrode sheet layer on the surface of the above-described hydrogel layer opposite to the microneedles.

[0051] Figure 3 is a cross-sectional view showing one form of the microneedle device of the present invention including an electrode sheet layer.

[0052] As shown in Figure 3, the microneedle device 200 of the present invention includes, in this order, an electrode sheet layer 4, an adhesive layer 1 having one or more apertures 1a, and a microneedle sheet layer 10 including a base material 2 and a plurality of microneedles 3 protruding from the base material 2. Although not shown in Figure 3, the electrode sheet layer 4 may have an aperture at the same position as the aperture 1a of the adhesive layer 1.

[0053] Without being limited to theory, the preferred reason for the microneedle device of the present invention to include an electrode sheet layer is considered as follows.

[0054] That is, the electrode sheet layer can apply a pulse wave having a predetermined frequency to the skin. Thereby, it becomes possible to generate collagen in the skin, moisturize the skin, and improve wrinkles. Therefore, it is expected that the combination of collagen generation in the skin by the electrode sheet layer and the diffusion of components such as hyaluronic acid into the skin by the microneedle sheet layer will give high cosmetic effects such as moisture, firmness, and elasticity maintenance to the skin.

[0055] In addition, the electrode sheet layer can more easily adhere to the skin and apply a pulsed wave to the skin through the adhesive layer of the micro-needle device of the present invention. In other words, the adhesive layer also helps to exert the effect of the electrode sheet layer.

[0056] Hereinafter, the details of the electrode sheet layer will be described.

[0057] In the present invention, the mode of the electrode sheet layer is not particularly limited as long as it can apply a pulsed current to the skin. For example, as one mode, the electrode sheet layer has first and second sheet-shaped electrodes independent of each other, and each of the first and second sheet-shaped electrodes is connected to a current generation unit through a conductive cable, and a pulsed current can be applied to the skin through the adhesive layer. An example thereof is shown in FIG. 4.

[0058] In FIG. 4, the electrode sheet layer has first and second sheet-shaped electrodes 72a and 72b. The first and second sheet-shaped electrodes 72a and 72b are independent of each other and can be attached to a desired part of the user's skin through the adhesive layer H. The first and second sheet-shaped electrodes 72a and 72b are electrically connected to the current generation unit 70 by cables 76a and 76b. In the example shown in FIG. 4, 76a and 76b are respectively connected to the first and second sheet-shaped electrodes 72a and 72b. The cables 76a and 76b have a common pin jack or pin plug 76c (not shown) for connecting to the current generation unit 70 at the other end.

[0059] Although not shown in FIG. 4, the adhesive layer H may have one or more openings. In this case, the sheet-shaped electrodes 72a and 72b may or may not have openings at portions overlapping the openings of the adhesive layer H. Further, when the sheet-shaped electrodes 72a and 72b have one or more openings, the respective openings may partially overlap or completely overlap the openings of the adhesive layer H.

[0060] In another aspect, the electrode sheet layer includes a single sheet-shaped electrode having a first electrode portion, a second electrode portion, and an insulating portion provided between the first and second electrode portions. The single sheet-shaped electrode has first and second terminals electrically connected to the first and second electrode portions respectively, and the first and second terminals are connected to a current generating unit, and a pulsed current can be applied to the skin through an adhesive layer. An example thereof is shown in FIG. 5.

[0061] In FIG. 5, the electrode sheet layer has a single sheet-shaped electrode 82. The sheet-shaped electrode 82 includes a first electrode portion 82a and a second electrode portion 82b, and an insulating portion 82c is provided therebetween. The first and second electrode portions 82a, 82b and the insulating portion 82c are formed as a single sheet-shaped member. The sheet-shaped electrode 82 has first and second electrode-side terminals (not shown) connected to the first and second electrode portions 82a, 82b. The current generating unit 80 includes first and second power-side terminals (not shown) that can be detachably coupled to the first and second electrode-side terminals in a hook or snap manner. By coupling the first and second electrode-side terminals to the first and second electrode-side terminals, the sheet-shaped electrode 82 is connected to the current generating unit 80 without passing through a cable. At this time, the current generating unit 80 is attached to the sheet-shaped electrode 82.

[0062] Although not shown in FIG. 5, the adhesive layer H may have one or more apertures. In this case, the sheet-shaped electrodes 82a and 82b may or may not have apertures in the portions overlapping the apertures of the adhesive layer H. Also, when the sheet-shaped electrodes 82a and 82b have one or more apertures, the respective apertures may partially overlap or completely overlap the apertures of the adhesive layer H.

[0063] In the present invention, the material of the electrode sheet layer is not particularly limited, and for example, it may be a conductive polymer having flexibility such that it can follow the unevenness of the skin, carbon black, resin, dielectric elastomer actuator (DEA), IPMC actuator, PVC gel, or the like. Further, it may be thin so as to be attachable to the user's skin, transparent so as not to be conspicuous when worn, or may be in a form matching the color of the user's skin. The electrode sheet layer may be reusable or disposable even when repeatedly used.

[0064] Also, as described above, the electrode sheet layer may be used as a base material of the adhesive layer. In this case, a laminate of the electrode sheet layer and the hydrogel may be regarded as the adhesive layer, and one or more openings may be provided.

[0065] 〈Support layer〉 The microneedle device of the present invention may further include a support layer. This support layer may be disposed, for example, in the opening of the adhesive layer. Thereby, the microneedle sheet layer is supported by the support layer. By including this support layer, the microneedle sheet layer can be easily arranged to overlap the opening of the adhesive layer, that is, a structure in which the microneedle sheet layer and the adhesive layer do not easily come into contact can be obtained.

[0066] For example, FIG. 6 is a cross-sectional view showing one form of the microneedle device of the present invention including a support layer.

[0067] As shown in FIG. 6, the microneedle device 300 of the present invention includes an adhesive layer 1 having one or more openings 1a, a base material 2, a microneedle sheet layer 10 including a plurality of microneedles 3 protruding from the base material 2, and a support layer 5 disposed in the opening 1a of the adhesive layer 1. Here, the microneedle sheet layer 10 is supported by the support layer 5.

[0068] The material constituting the support layer is not particularly limited and may be, for example, a resin that does not dissolve or swell in vivo and does not affect the living body. More specifically, the material constituting the support layer may be, for example, polymethyl methacrylate, cellulose acetate, ethyl cellulose, polyethylene resin, polypropylene resin, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, vinyl chloride-based resin, vinylidene chloride resin, vinyl acetate-vinyl chloride copolymer, polyamide-based resin, polyester resin, ABS resin, SIS resin, SEBS resin, urethane resin, silicone resin, aluminum, etc., but is not limited thereto.

[0069] The thickness of the support layer is not particularly limited and may be, for example, the same thickness as the adhesive layer.

[0070] <Other members> In addition to the members described above, the microneedle device of the present invention may further include other members as long as the effects of the present invention are not impaired.

[0071] The microneedle device of the present invention may further include, for example, a protective sheet layer. The protective sheet layer can be used for the purpose of covering the portion where the adhesive layer is exposed. The protective sheet layer may be peeled off immediately before applying the microneedle device of the present invention to the skin.

[0072] The material constituting the protective sheet layer is not particularly limited and may be, for example, a film such as polyethylene, polypropylene, or polyester.

[0073] <Manufacturing method> The manufacturing method of the microneedle device of the present invention is not particularly limited and may be performed, for example, by preparing and assembling each member as necessary.

[0074] (Preparation of the adhesive layer) The adhesive layer according to the present invention can be obtained by applying one or more apertures to a commercially available one or a material obtained by applying an adhesive component onto a substrate.

[0075] Also, when using an electrode sheet layer as the base material of the adhesive layer, it can be obtained by applying an adhesive on the electrode sheet layer and then making one or more openings. Further, it can also be obtained by making one or more openings in a commercially available electrode sheet layer with an adhesive layer.

[0076] (Preparation of the micro-needle sheet layer) The micro-needle sheet layer according to the present invention can be obtained, for example, by the following method.

[0077] Method (1) A method of casting an aqueous solution of a material mainly composed of a micro-needle forming material such as hyaluronic acid, to which a pharmaceutical component or a cosmetic component is added as necessary, into a mold having the shape of a micro-needle, drying by evaporating moisture at room temperature or by heating, laminating a substrate, and then peeling it off to transfer the micro-needles onto the base material.

[0078] Method (2) A method of casting a layer of the above aqueous solution on the surface of the mold of the above method (1), drying by evaporating moisture at room temperature or by heating, and then peeling it off. In this method, a micro-needle sheet layer in which both the base material and the micro-needles are made of a material mainly composed of a micro-needle forming material to which a pharmaceutical component or a cosmetic component is added as necessary can be obtained.

[0079] Method (3) A method of injection molding an aqueous solution of a material mainly composed of a micro-needle forming material to which a pharmaceutical component or a cosmetic component is added as necessary into the shape of a micro-needle on a substrate, and then drying by evaporating moisture at room temperature or by heating.

[0080] 〈Use〉 The micro-needle device of the present invention is particularly suitable for skin care.

[0081] Here, as skin care, examples include, but are not limited to, moisturizing, whitening, wrinkle improvement, stain improvement, skin tone unevenness improvement, sagging improvement, dullness improvement, dark circle improvement, pore improvement, acne improvement, firmness, or imparting elasticity, etc.

[0082] In addition, the microneedle device of the present invention may be individually or packaged in several pieces for use in skin care. The packaging is preferably a vacuum packaging that seals the microneedle device of the present invention and reduces the pressure inside.

[0083] 《Beauty method》 The present invention also provides a beauty method.

[0084] As one form of the beauty method according to the present invention, it is shown below.

[0085] That is, the first beauty method of the present invention is A beauty method using the microneedle device of the present invention, including penetrating at least a part of the constituent material of the microneedle into the skin by attaching and closely adhering the microneedle side of the microneedle device to the skin. Beauty method is.

[0086] For example, FIG. 7 is a schematic diagram for explaining one aspect of the first beauty method of the present invention. As shown in FIG. 7, the beauty method of the present invention uses a microneedle device 400. As shown in the right figure of FIG. 7, by attaching and closely adhering the microneedle side of the microneedle device 400 to the skin S, at least a part of the constituent material of the microneedle penetrates into the skin. At this time, when the adhesive layer 1 contains moisture, for example, when the adhesive layer is a hydrogel layer, it is possible to supply moisture from around the microneedle to the skin S.

[0087] In the micro-needle device 400, the micro-needle sheet layer 100 is configured to enter the openings of the adhesive layer 1, and an adhesive 6 is provided between the micro-needle sheet layer 100 and the adhesive layer 1. The adhesive 6 fixes the micro-needle sheet layer 100 and the adhesive layer 1 and prevents their direct contact.

[0088] As another form of the beauty method according to the present invention, it is shown below.

[0089] That is, the second beauty method of the present invention is A beauty method using the micro-needle device of the present invention, By attaching and closely adhering the micro-needle side of the micro-needle device to the skin, at least a part of the constituent material of the micro-needle penetrates into the skin, and Applying a pulsed current to the skin through the electrode sheet layer, including beauty method is.

[0090] For example, FIG. 8 is a schematic diagram for explaining one aspect of the second beauty method of the present invention. As shown in FIG. 8, the beauty method of the present invention uses a micro-needle device 500. As shown in the right diagram of FIG. 8, by attaching and closely adhering the micro-needle side of the micro-needle device 500 to the skin S, at least a part of the constituent material of the micro-needle penetrates into the skin, and a pulsed current is applied to the skin through the electrode sheet layer 4. At this time, when the adhesive layer 1 contains moisture, for example, when the adhesive layer is a hydrogel layer, it is possible to supply moisture from around the micro-needles to the skin S.

[0091] Note that the micro-needle device 500 is the same as the micro-needle device 400 except that it further includes an electrode sheet layer 4 on the surface of the adhesive layer 1 of the micro-needle device 400 in FIG. 7 opposite to the micro-needles, and the description thereof is omitted.

[0092] In the second beauty method of the present invention, the pulsed current may have a frequency in the range of, for example, 100 to 5000 Hz, more preferably 200 to 5000 Hz, and still more preferably 500 to 2000 Hz. Also, the current value of the pulsed current can be arbitrarily selected, for example, 100 μA to 1000 μA, 150 μA to 1000 μA, 200 μA to 500 μA, etc. Preferably, it is 200 μA to 500 μA. Since the current value in such a range is equivalent to the current value in human skin, it has little adverse effect on the skin. The voltage can be arbitrarily selected within a range that does not cause adverse effects on the skin, such as 1.0 V to 10.0 V, 5.0 V to 10.0 V, 1.0 V to 5.0 V, etc. The waveform of the pulse wave and voltage can be arbitrarily set, such as a pulse shape, a rectangular wave, a sine wave, a triangular wave, a sawtooth wave, etc.

[0093] In the beauty method of the present invention, the time for at least a part of the constituent material of the microneedle to penetrate the skin is not particularly limited, and may be, for example, 1 hour or more, 3 hours or more, 6 hours or more, or 12 hours or more, and may also be 24 hours or less, or 12 hours or less.

[0094] In the second beauty method of the present invention, the time for applying the pulsed current to the skin is not particularly limited, and may be, for example, 1 minute or more, 5 minutes or more, 10 minutes or more, 20 minutes or more, or 40 minutes or more, and may also be 8 hours or less, 4 hours or less, 3 hours or less, 2 hours or less, or 1 hour or less.

[0095] Also, the frequency of performing the beauty method of the present invention is not particularly limited, and it may be performed continuously or intermittently, regularly or irregularly, such as once a day, once every 2 days, once every 3 days, once every 4 days, once every 5 days, once every 6 days, once every 7 days, once every 1, 2, 3, 4 weeks, etc.

Examples

[0096] Examples are given below to explain the present invention in more detail, but the present invention is not limited thereto.

[0097] 《Examples 1 and 2, and Comparative Example 1》 〈Example 1〉 In Example 1, a conductive carbon sheet was used as the electrode sheet layer. An adhesive layer containing moisture was laminated on this electrode sheet layer to form a laminate of a 20 mm × 20 mm square electrode sheet and the adhesive layer. Then, a circular opening with a diameter of 8 mm was provided at the center of this laminate. On the other hand, a circular micro-needle with a diameter of 9 mm and an area of 64 mm 2 was prepared, and an adhesive was applied in a ring shape to a region 2 mm from the outer periphery of the micro-needle sheet layer, and the micro-needle was laminated on the laminate through the adhesive so that the micro-needle sheet layer and the opening of the laminate overlapped, and a micro-needle device 1 was fabricated.

[0098] Note that, as the micro-needle, a micro-needle sheet layer (area 64 mm 2 ) formed of 138 hyaluronic acids with a height of 200 μm and containing 2 mass% of a fluorescent agent was used.

[0099] <Example 2> In Example 2, a micro-needle device 2 was fabricated in the same manner as in Example 1, except that the electrode sheet layer was not provided.

[0100] <Comparative Example 1> In Comparative Example 1, simply the micro-needle of Example 1 was used as a macro-needle device 3 without having an electrode sheet layer and an adhesive layer.

[0101] <Measurement of Penetration Strength> Using each of the micro-needle devices of Example 1 and 2 and Comparative Example 1, they were applied to human skin, and the penetration strength of each hyaluronic acid was examined.

[0102] More specifically, in Example 1, the micro-needle device 1 was attached to human skin, and using a fixing device, the micro-needle device 1 and the skin were firmly fixed, and a minute current of a pulse wave of 5 V, 250 μA, and 500 Hz was applied to the skin through the electrode sheet for 1 hour. Then, the fixing device was removed, and a minute current was continuously applied to the skin for an additional 1.5 hours.

[0103] Subsequently, the micro-needle device 1 was removed, the surface of the skin at the site where the micro-needles had been applied was cleaned, and a portion of the skin was cut out in a circle with a diameter of 8 mm using a cutter. The obtained skin was placed in 400 μL of methanol and subjected to ultrasonic treatment to extract the fluorescent dye. Then, 200 μL of the extracted sample was measured for fluorescence intensity (Ex: 488 nm, Em: 515 nm) using a spectrophotometer. The measurement results were evaluated as the penetration intensity of the micro-needle device 1 and are shown in FIG. 9.

[0104] In Example 2, after the micro-needle device 2 was applied to human skin for 2.5 hours, the fluorescence intensity was measured in the same manner as in Example 1. The results of the obtained penetration intensity are shown in FIG. 9.

[0105] In Comparative Example 1, after the micro-needle device 3 was applied to human skin for 2.5 hours, the fluorescence intensity was measured in the same manner as in Example 1. The results of the obtained penetration intensity are shown in FIG. 9.

[0106] As is clear from FIG. 9, it was found that both the micro-needle devices 1 and 2 of Examples 1 and 2 had a higher penetration intensity of hyaluronic acid compared to the case of Comparative Example 1. In particular, it was found that the micro-needle device 1 of Example 1 had the highest penetration intensity of hyaluronic acid.

[0107] <<Comparative Example 2>> In Comparative Example 2, a micro-needle device 4 was fabricated in the same manner as in Example 2, except that the adhesive layer was not provided with apertures.

[0108] Then, after the micro-needle device 4 was applied to human skin for 2.5 hours, the fluorescence intensity was measured in the same manner as in Example 1. The results of the obtained penetration intensity are shown in FIG. 10.

[0109] Also, for comparison with Comparative Example 2, the results of Example 2 are also shown in FIG. 10.

[0110] As is clear from the results of FIG. 10, it was found that the microneedle device 2 (Example 2) having apertures in the adhesive layer had a higher penetration strength of hyaluronic acid than the microneedle device 4 (Comparative Example 2) having no apertures in the adhesive layer.

Explanation of Symbols

[0111] 1, 1A, 1B, 1C, 1D, 1E, H Adhesive layer 1a, 1b, 1c, 1d, 1e, Apertures 2 Substrate of microneedle sheet layer 3 Microneedles 4 Electrode sheet layer 5 Support layer 6 Adhesive 10 Microneedle sheet layer 70, 80 Current generating part 72a, 72b, 82 Sheet-like electrodes 76a, 76b Cables 82a First electrode part 82b Second electrode part 82c Insulating part 100, 200, 300, 400, 500 Microneedle devices S Skin

Claims

1. A microneedle device comprising an adhesive layer and a microneedle sheet layer, wherein the adhesive layer has one or more apertures, the microneedle sheet layer has a substrate and a plurality of microneedles protruding from the substrate, the substrate and the microneedles are formed of a material that can dissolve or swell in vivo, and the microneedle sheet layer is disposed so as to at least partially overlap the apertures of the adhesive layer, a microneedle device.

2. The microneedle device according to claim 1, further comprising an electrode sheet layer on a surface of the adhesive layer opposite to the side of the microneedles.

3. The microneedle device according to claim 1, wherein the microneedle sheet layer is disposed so as to overlap the apertures of the adhesive layer or inside the apertures.

4. further comprising a support layer, wherein the support layer is disposed in the apertures of the adhesive layer, and the microneedle sheet layer is supported by the support layer, the microneedle device according to claim 1.

5. The microneedle device according to claim 1, wherein the material that can dissolve or swell in vivo is hyaluronic acid.

6. The microneedle device according to claim 1, which is for skin care.

7. A beauty method using the microneedle device according to any one of claims 1 to 6, comprising permeating at least a part of the constituent material of the microneedles into the skin by attaching and closely adhering the microneedle side of the microneedle device to the skin. A beauty method.

8. A beauty method using the microneedle device according to any one of claims 2 to 6, comprising permeating at least a part of the constituent material of the microneedles into the skin by attaching and closely adhering the microneedle side of the microneedle device to the skin, and applying a pulsed current to the skin through the electrode sheet layer, including a beauty method.

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