Microneedle patch

Abstract

[Problem] To reduce the burden of discarded plastics on the environment. [Solution] This microneedle patch (10) comprises an adhesive tape (20) and a plurality of microneedles (32). The adhesive tape (20) has a base material sheet (21) and an adhesive layer (25). The adhesive layer (25) fixes the plurality of microneedles (32) to the base material sheet (21). The base material sheet (21) has a base material paper (23) and a coating (24).

Description

Microneedle patch

[0001] This disclosure relates to a microneedle patch.

[0002] The transdermal patch disclosed in Patent Document 1 (Japanese Patent No. 5931155) is for non-invasively administering drugs through the body surface, such as the skin or mucous membrane. The transdermal patch has a plurality of microneedles and a support that supports them. The material of the microneedles is a water-soluble polymer to which the drug has been added. The support is a nonwoven fabric with good breathability.

[0003] Patent No. 5931155

[0004] For the water-soluble polymers that make up microneedles to be absorbed into the body, the microneedles need to be dissolved by water vapor emitted from the body surface. If a breathable nonwoven fabric is used as the support material, the water vapor will pass through the support and dissipate, which may prevent the microneedles from dissolving efficiently. To promote dissolution, it is preferable to use a synthetic resin sheet with poor breathability as the support material. However, if a synthetic resin support is used in a disposable transdermal patch, the waste generated after use of the transdermal patch will contain plastic, which can be an environmental burden.

[0005] The objective of this disclosure is to reduce the environmental burden caused by discarded transdermal patches.

[0006] Several embodiments for solving the problem are described below. These embodiments can be combined as needed.

[0007] A microneedle patch according to one aspect of this disclosure comprises an adhesive tape and a plurality of microneedles. The adhesive tape has a base sheet and an adhesive layer. The adhesive layer fixes the plurality of microneedles to the base sheet. The base sheet has a base paper and a coating.

[0008] Preferably, the microneedle patch further comprises a base. The base is formed integrally with a plurality of microneedles. The base connects the plurality of microneedles.

[0009] Preferably, the base paper contains plant fibers.

[0010] Preferably, the base paper includes at least one of the following: glassine paper, white paper, kraft paper, Japanese paper, newsprint paper, parchment paper, rice paper, matte paper, and unmodified cellophane.

[0011] Preferably, the base paper is glassine paper.

[0012] Preferably, the coating is a natural wax or resin of plant or animal origin.

[0013] Preferably, the natural wax comprises at least one of carnauba wax, candelilla wax, Japanese wax, rice wax, sugarcane wax, soy wax, palm wax, jojoba wax, sunflower wax, and beeswax. The natural resin comprises shellac.

[0014] Preferably, the coating is carnauba wax.

[0015] Preferably, the base sheet has one or more layers of base paper. The total thickness of all layers of base paper in the base sheet is 25 μm or more.

[0016] Preferably, the base sheet has one or more layers of coating. In the base sheet, the weight of one or more layers of coating per unit area of ​​the base paper is 0.5 g / m². ２ That's all.

[0017] Preferably, the base paper has at least a first base paper layer and a second base paper layer. The coating has at least a first coating layer in contact with the first base paper layer and a second coating layer in contact with the second base paper layer. At least one of the first coating layer or the second coating layer is positioned between the first base paper layer and the second base paper layer.

[0018] Preferably, the microneedle patch further comprises an intermediate adhesive layer, which is located between the first base paper layer and the second base paper layer.

[0019] Preferably, the first base paper layer is in contact with the adhesive layer. The first coating layer is in contact with the first base paper layer. The intermediate adhesive layer is in contact with the first coating layer. The second base paper layer is in contact with the intermediate adhesive layer. The second coating layer is in contact with the second base paper layer.

[0020] Preferably, both the first base paper layer and the second base paper layer have a thickness of 25 μm or more.

[0021] Preferably, the adhesive layer can come into contact with the user's skin, thereby allowing multiple microneedles to penetrate the skin.

[0022] Preferably, the plurality of microneedles are composed of a substance that is biosoluble or biodegradable.

[0023] Preferably, the adhesive tape has a density of 40 g / m². ２ The water vapor transmission rate is as follows (per day).

[0024] According to the configuration of this disclosure, the base sheet of the adhesive tape is manufactured using paper as the basis. Therefore, compared to the case in which the base sheet is manufactured using a synthetic resin base, the amount of plastic discharged when the microneedle patch is disposed of can be reduced, thereby reducing the environmental burden.

[0025] This is a perspective view showing the schematic configuration of the microneedle patch 10 of the first embodiment and its modified form. This is a schematic cross-sectional view showing the product unit 90 of the microneedle patch 10 of the first embodiment and its modified form. This is a schematic cross-sectional view showing the basic concepts common to the configuration of the first embodiment and its modified form. This is a schematic cross-sectional view showing the configuration of the microneedle patch 10 of the first embodiment. This is a schematic diagram showing the configuration of the adhesive tape 20 of the first embodiment. This is a schematic diagram showing the penetration of the coating 24 into the base paper 23 in the adhesive tape 20 of the first embodiment. This is a schematic diagram showing the configuration of the adhesive tape 20 according to the first modified form of the first embodiment. This is a schematic diagram showing the configuration of the adhesive tape 20 according to the second modified form of the first embodiment. This is a schematic diagram showing the configuration of the adhesive tape 20 according to the third modified form of the first embodiment. This is a schematic diagram showing the configuration of the adhesive tape 20 according to the fourth modified form of the first embodiment. This is a perspective view showing the schematic configuration of the microneedle patch 10 of the second embodiment and its modified form. This is a schematic cross-sectional view showing the product unit 90 of the microneedle patch 10 of the second embodiment and its modified form. This is a schematic cross-sectional view showing the basic concepts common to the configuration of the second embodiment and its modified form. This is a schematic cross-sectional view showing the configuration of the microneedle patch 10 according to the second embodiment.

[0026] <First Embodiment> (1) Schematic diagram 1 shows the schematic configuration of the microneedle patch 10 of the first embodiment and its modified form. The microneedle patch 10 is used to allow the user to absorb the drug into their body by being applied to the user's skin. The microneedle patch 10 has a plurality of microneedles 32 that contain the drug or are the drug itself. When the microneedles 32 penetrate the user's skin, the drug is supplied to the stratum corneum of the skin.

[0027] Figure 2 shows a schematic configuration of a product unit 90 for distributing the microneedle patch 10 of this embodiment and its modified form as a commercial product. The product unit 90 comprises a microneedle patch 10 and a protective sheet 80. The microneedle patch 10 comprises an adhesive tape 20 and a microneedle sheet 30. The microneedle sheet 30 has a plurality of microneedles 32. The protective sheet 80 is for protecting the plurality of microneedles 32 during the distribution process. The user peels off the protective sheet 80 immediately before use, exposing the microneedle sheet 30.

[0028] Figure 3 shows the basic concept common to this embodiment and its modifications. As described above, the microneedle patch 10 includes an adhesive tape 20 and a microneedle sheet 30.

[0029] (1-1) Adhesive Tape 20 The adhesive tape 20 is for supporting the microneedle sheet 30 and fixing it to the user's skin. The adhesive tape 20 is expected to move in accordance with the stretching of the skin and to provide the user with a comfortable fit. For this purpose, the thickness T of the adhesive tape 20 is set to 1 mm or less. Preferably, the thickness T of the adhesive tape 20 is set to 500 μm or less. The adhesive tape 20 has a base sheet 21 and an adhesive layer 25.

[0030] (1-1-1) Base sheet 21 The base sheet 21 supports the microneedle sheet 30 and is intended to suppress the passage of water vapor. The base sheet 21 has a base paper 23 and a coating 24.

[0031] (1-1-1-1) Base paper 23 The base paper 23 is the basic component of the adhesive tape 20. The base paper 23 is made from paper manufactured using natural materials. The base paper 23 is typically made from plant-derived materials and contains plant fibers. The specific types of materials for the base paper 23 will be described later. The base paper 23 contained in one sheet of adhesive tape 20 may consist of a single layer or multiple layers. If the base paper 23 consists of multiple layers, the multiple layers do not necessarily have to be in contact with each other and may be separated from each other.

[0032] Preferably, the total thickness of all layers of the base paper 23 in the base sheet 21 is 25 μm or more. Having a certain thickness or more of the base paper 23 gives the microneedle sheet 10 appropriate rigidity, allowing the user to perceive the feel of the microneedle sheet 10 when grasping it. This makes it easier for the user to manipulate the microneedle sheet 10 and peel off the protective sheet 80 from the microneedle sheet 10. In addition, by giving the base paper 23 an appropriate thickness, the conformability of the microneedle sheet 10 to the surface of the skin can be adjusted, reducing discomfort when wearing it.

[0033] (1-1-1-2) Coating 24 The coating 24 is intended to contain water vapor near the body surface by suppressing the passage of water vapor emitted from the body surface of the user of the microneedle patch 10. Due to the presence of the coating 24, the water vapor permeability of the adhesive tape 20 is 40 (g / m²). ２ The value is kept small, such as less than or equal to ( / day). In order to ensure that the water vapor barrier performance of the coating 24 is above a certain level, the base sheet 21 has one or more layers of coating 24 per unit area of ​​the base paper 23, with a weight of 0.5 g / m². ２ The product is manufactured to meet the above specifications. Here, "unit area of ​​base paper 23" refers to the unit area of ​​a single layer if the base paper 23 is formed from multiple layers. In other words, "unit area of ​​base paper 23" is synonymous with the unit area of ​​the adhesive tape 20 or base sheet 21.

[0034] The coating 24 is made from natural materials. The coating 24 is a plant-derived or animal-derived substance. The specific types of materials for the coating 24 will be described later. The coating 24 contained in one adhesive tape 20 may consist of a single layer or multiple layers. If the coating 24 consists of multiple layers, the multiple layers do not necessarily have to be in contact with each other and may be separated from each other.

[0035] The coating 24 is laminated on the base paper 23. Alternatively, part or all of the volume of the coating 24 may penetrate into the base paper 23.

[0036] (1-1-2) Adhesive layer 25 The adhesive layer 25 is for fixing the microneedle sheet 30 to the user's skin by adhering to it. The adhesive layer 25 is made of a substance that exhibits adhesiveness. The area of ​​the adhesive layer 25 is larger than the area of ​​the microneedle sheet 30. Of the adhesive layer 25, the support area R1 that is in contact with the microneedle sheet 30 fixes the base sheet 21 and the microneedle sheet 30. Of the adhesive layer 25, the contact area R2 that is not covered by the microneedle sheet 30 fixes the microneedle sheet 30 to the user's skin by coming into contact with it. As the adhesive layer 25 adheres to the user's skin, multiple microneedles 32 can penetrate the skin.

[0037] (1-2) Microneedle sheet 30 The microneedle sheet 30 is for holding a drug to be delivered into the body of a user. The microneedle sheet 30 may be configured as a carrier into which the drug has been impregnated. Alternatively, the microneedle sheet 30 may be constituted of the drug itself. The microneedle sheet 30 is typically composed of a water-soluble polymer that exhibits in vivo solubility or biodegradability. Examples of the drug or carrier constituting the microneedle sheet 30 include sodium hyaluronate, sodium chondroitin sulfate, water-soluble collagen, water-soluble chitosan, and dextran. As described above, the adhesive tape 20 traps water vapor in the vicinity of the user's body surface. At this time, the microneedle sheet 30 is dissolved by the water vapor.

[0038] The microneedle sheet 30 has a sheet-shaped base portion 31 and a plurality of microneedles 32 extending generally perpendicularly from the base portion 31. The base portion 31 and the plurality of microneedles 32 are integrally formed from the same material. The base portion 31 connects the plurality of microneedles 32 to each other. The base portion 31 is fixed to the adhesive tape 20 by being in close contact with the adhesive layer 25 over a wide area. The plurality of microneedles 32 deliver the drug into the user's body by penetrating into the skin. At this time, the drug is delivered to, for example, the stratum corneum of the skin. The height H of the microneedles 32 is, for example, 20 µm or more and 1000 µm or less. Preferably, the height H of the microneedles 32 is 50 µm or more and 200 µm or less.

[0039] (2) Material of base paper 23 The base paper 23 is composed of at least one selected from glassine paper, fine white paper, kraft paper, Japanese paper, newsprint paper, parchment paper, rice paper, matte paper, and unchemically modified cellophane.

[0040] Glassine paper is generally smooth, glossy, translucent when undyed, and a paper excellent in air resistance, water resistance, and oil resistance. The raw material of glassine paper is sulfite pulp (SP). Sulfite pulp is produced by cooking wood chips in a sulfite solution and contains plant fibers. In the manufacturing process of glassine paper, a paper web made from wood chips is pressurized and dried, then subjected to a supercalendering process. In the supercalendering process, the paper web passes through a set of rollers covered with steel and fiber, which is called a supercalender. Through this supercalendering process, the plant fibers of glassine paper are oriented in the same direction. This gives glassine paper a high-quality texture. Therefore, by using glassine paper as the base paper 23, the microneedle patch 10 can provide a comfortable wearing feeling for the user.

[0041] Woodfree printing paper (also called high-grade paper, white high-grade paper) is a paper made from chemical pulp (CP) as a raw material. Chemical pulp is produced by extracting plant fibers from wood using chemicals. Woodfree printing paper is uncoated, with pulp exposed on its surface.

[0042] The raw material of kraft paper is kraft pulp produced by the kraft process. In the kraft process, alkaline chemicals such as caustic soda are added to wood chips, which are then cooked under high-temperature and high-pressure conditions. Kraft paper has high strength due to the long plant fibers contained in kraft pulp.

[0043] Washi (Japanese paper) is a paper manufactured from plant materials other than wood pulp, and contains relatively long plant fibers. Raw materials for washi include, for example, hemp, the bark of Mitsumata, and the bark of Kozo.

[0044] Newsprint paper is a low-cost paper made from thermomechanical pulp (TMP) or recycled paper. Thermomechanical pulp is produced by heating wood chips with steam to soften them, and then extracting plant fibers using a pulverizer under high temperature and pressure.

[0045] Parchment paper (also known as sulfuric acid paper) is a type of paper that resembles parchment (sheepskin paper) made from sheep or goat hides, and is made from chemical pulp. Chemical pulp is produced by extracting plant fibers from wood using chemicals. In the production process of parchment paper, the paper made from chemical pulp is treated with sulfuric acid solution.

[0046] Rice paper is a type of paper made from materials such as the branches of the rice paper plant, rice straw, and the bark of the paper mulberry tree.

[0047] Matte photo paper (matte coated paper) is a type of paper in which a matte coating is applied to the surface of the base paper. The base paper is made from wood pulp or similar materials.

[0048] Non-chemically modified cellophane is cellophane that has not undergone any chemical treatment to alter the functional groups in its molecular structure. Cellophane is often made from wood pulp, but it can also be made from plant fibers such as cotton or hemp.

[0049] (3) Materials of Coating 24 The coating 24 is composed of natural substances of plant or animal origin. These natural substances are, for example, natural waxes or natural resins. Natural waxes include carnauba wax, candelilla wax, Japanese wax, rice wax, sugarcane wax, soy wax, palm wax, jojoba wax, sunflower wax, and beeswax. Natural resins include shellac.

[0050] Carnauba wax is a wax obtained from the leaves of the Brazilian carnauberia palm, which grows naturally in Brazil. Carnauba wax is obtained by refining the wax obtained by pounding dried Brazilian carnauberia palm leaves. Carnauba wax has a high melting point of 82-86°C. Therefore, by using carnauba wax in coating 24, the quality of the microneedle patch 10 is less likely to be compromised in high-temperature environments.

[0051] Candelilla wax is a wax obtained from the candelilla plant, which grows in desert regions of the United States and Mexico.

[0052] Japan wax is a wax obtained from the fruits of the Japanese wax tree (Rhus succedanea) and the lacquer tree (Rhus urushi). It is obtained from the fatty components extracted by steaming and then pressing the fruits of these plants.

[0053] Rice bran wax is a wax obtained from rice bran oil, which is extracted from rice bran. Rice bran wax has a high melting point of 77-86°C.

[0054] Sugarcane wax is a wax obtained from the bagasse (the residue left over after pressing sugarcane stalks to produce sugar).

[0055] Soy wax is a wax obtained from soybean oil, which is extracted from soybeans.

[0056] Palm wax is a wax obtained from palm oil, which is extracted from the oil palm tree.

[0057] Jojoba wax is a wax obtained from jojoba oil, which is extracted from the seeds of the jojoba plant, native to the United States and Mexico.

[0058] Sunflower wax is a wax obtained from sunflower oil, which is extracted from sunflower seeds.

[0059] Beeswax is a wax harvested from honeybeehives. Honeybees metabolize the sugars in honey, secreting a fat from wax glands in their abdomen. They then use their mouthparts to knead this fat and build their nests. Although animals are involved in the production of beeswax, a certain percentage of its components come from flower nectar.

[0060] Shellac is a resin secreted by the lac insect (Kerria lacca), a type of scale insect (Coccoidea). Lac insects infest leguminous and mulberry trees, feeding on the sap, and then secrete a covering substance. This covering substance forms a rod-shaped mass that surrounds the twigs of the host tree. Shellac can be obtained by refining this mass. Although animals are involved in shellac production, a certain percentage of the components of shellac wax originate from plants.

[0061] (4) Detailed configuration diagram 4 shows the specific configuration of the microneedle patch 10 of the first embodiment. In this embodiment, the adhesive tape 20 has a first set S1 and a second set S2 having the same laminated structure stacked on top of each other. The base paper 23 included in the adhesive tape 20 is composed of two layers that are separated from each other. The coating 24 included in the adhesive tape 20 is also composed of two layers that are separated from each other.

[0062] Figure 5 shows the configuration of the adhesive tape 20 of the microneedle patch 10 of this embodiment. The first set S1 has a first base paper layer 23a, a first coating layer 24a, and an adhesive layer 25. The second set S2 has a second base paper layer 23b, a second coating layer 24b, and an intermediate adhesive layer 25b.

[0063] The first base paper layer 23a is in contact with the adhesive layer 25. The first coating layer 24a is in contact with the first base paper layer 23a. The intermediate adhesive layer 25b is in contact with the first coating layer 24a. The second base paper layer 23b is in contact with the intermediate adhesive layer 25b. The second coating layer 24b is in contact with the second base paper layer 23b.

[0064] (4-1) Base paper 23 The base paper 23 of the adhesive tape 20 shown in Figure 4 is composed of a first base paper layer 23a and a second base paper layer 23b, as shown in Figure 5. It is preferable that both the first base paper layer 23a and the second base paper layer 23b have a thickness of 25 μm or more. Furthermore, it is preferable that the total thickness of all layers of the base paper 23, in other words, the total thickness of the first base paper layer 23a and the second base paper layer 23b, is at least 25 μm, and more preferably 50 μm or more and 70 μm or less. The first base paper layer 23a and the second base paper layer 23b are each composed of a material selected from the plurality of base paper 23 materials described above. Preferably, the first base paper layer 23a and the second base paper layer 23b are composed of the same material.

[0065] (4-2) Coating 24 The coating 24 of the adhesive tape 20 shown in Figure 4 is composed of a first coating layer 24a and a second coating layer 24b, as shown in Figure 5. Of the first coating layer 24a and the second coating layer 24b, the first coating layer 24a is positioned between a first base paper layer 23a and a second base paper layer 23b, which are separated from each other. The first coating layer 24a and the second coating layer 24b are each composed of a material selected from the plurality of materials of the coating 24 described above. Preferably, the first coating layer 24a and the second coating layer 24b are composed of the same material.

[0066] In the configuration shown in Figure 5, in the first set S1, the first coating layer 24a is laminated on the first base paper layer 23a, and in the second set S2, the second coating layer 24b is laminated on the second base paper layer 23b. Alternatively, as shown in Figure 6, part or all of the volume of the coating 24 may penetrate into the base paper 23. In Figure 6, a part of the volume of the material constituting the first coating layer 24a penetrates into the first base paper layer 23a to form the first penetration region 29a. Also, a part of the volume of the material constituting the second coating layer 24b penetrates into the second base paper layer 23b to form the second penetration region 29b.

[0067] As described above, in both the configuration of Figure 5 and the configuration of Figure 6, the weight of the coating 24 per unit area of ​​the base paper 23, in other words, the sum of the weights of the first coating layer 24a and the second coating layer 24b per unit area of ​​the adhesive tape 20 is 0.5 g / m². ２ That's all.

[0068] (4-3) Adhesive layer 25 The adhesive layer 25 belonging to the first set S1 is for fixing the microneedle sheet 30 to the user's skin by adhering to it. In this disclosure, the adhesive layer 25 is treated as not being included in the base sheet 21.

[0069] (4-4) Intermediate adhesive layer 25b The intermediate adhesive layer 25b belonging to the second set S2 fixes the first set S1 and the second set S2 to each other. Specifically, the intermediate adhesive layer 25b fixes the first coating layer 24a of the first set S1 and the second base paper layer 23b of the second set S2. The intermediate adhesive layer 25b is positioned between the first base paper layer 23a and the second base paper layer 23b, which are separated from each other. Preferably, the intermediate adhesive layer 25b is made of the same material as the adhesive layer 25. In this disclosure, the intermediate adhesive layer 25b is treated as a component of the base sheet 21.

[0070] (5) Features (5-1) About the base paper 23 The adhesive tape 20 is manufactured using a paper called base paper 23 as the base. The base paper 23 that provides the base is made of plant-derived materials and contains biodegradable plant fibers.

[0071] Therefore, the microneedle patch 10 of this embodiment can reduce the amount of plastic discharged at the time of disposal compared to the case where the adhesive tape 20 is manufactured using a synthetic resin base, thus reducing the burden on the environment.

[0072] In recent years, the Single-use Plastics Directive (SUP) issued by member states of the European Union has raised concerns about the burden that plastics, which are often found in single-use products, are placing on the global environment, such as the oceans. Since the microneedle patch 10 of this disclosure is manufactured using a biodegradable base paper 23, it can comply with the SUP Directive.

[0073] The base paper 23 can also be made of glassine paper with a good texture. In this case, the user of the microneedle patch 10 can be given a comfortable wearing experience.

[0074] The total thickness of the base paper 23 is 25 μm or more. Therefore, it is possible to prevent the microneedle patch 10 from becoming excessively flexible, making it easier for the user to manipulate the microneedle sheet 10 and peel off the protective sheet 80 from the microneedle sheet 10. In addition, the conformability of the microneedle sheet 10 to the skin surface can be adjusted, reducing discomfort when worn.

[0075] (5-2) About the coating 24 The coating 24 is a natural wax of plant or animal origin and is composed of easily biodegradable materials. Therefore, the environmental burden when the microneedle patch 10 is disposed of can be further reduced. Since it is manufactured using a biodegradable coating 24, the microneedle patch 10 of this disclosure can comply with the SUP Directive.

[0076] The coating 24 can also be made of carnauba wax, which has a high melting point. In this case, the quality of the microneedle patch 10 is less likely to be compromised in high-temperature environments.

[0077] The weight of the coating 24 per unit area of ​​the base paper 23 is 0.5 g / m². ２ The adhesive tape 20 has a viscosity of 40 (g / m²). ２ It exhibits a low water vapor transmission rate of less than or equal to ( / day). Therefore, water vapor emitted from the user's skin can be contained in the vicinity of the microneedle sheet 30, allowing for efficient dissolution or decomposition of the microneedles 32.

[0078] (5-3) Regarding the microneedle sheet 30, the multiple microneedles 32 are composed of a substance that dissolves or decomposes in the user's body. Therefore, the drug can be absorbed into the user's body.

[0079] Multiple microneedles 32 are integrally formed by the base portion 31. Therefore, since the multiple microneedles 32 are stably fixed to the base sheet 21, peeling of the microneedles 32 from the base sheet 21 is suppressed.

[0080] (5-4) Regarding the adhesive layer 25, the adhesive layer 25 has a contact area R2 that is large enough to fix the microneedle patch 10 to the user's skin. Therefore, the microneedles 32 can be penetrated into the user's skin.

[0081] (5-5) Repeated Lamination Structure The adhesive tape 20 has a repeated laminate structure. In the adhesive tape 20, a first set S1 consisting of a first base paper layer 23a, a first coating layer 24a, and an adhesive layer 25 is stacked, and a second set S2 consisting of a second base paper layer 23b, a second coating layer 24b, and an intermediate adhesive layer 25b is stacked. Therefore, the same material can be used for the first set S1 and the second set S2, making it easy to manufacture the base sheet 21 and the microneedle patch 10. In addition, the manufacturing cost of the adhesive tape 20 can be reduced.

[0082] The base paper 23 is composed of two layers, a first base paper layer 23a and a second base paper layer 23b. The coating 24 is also composed of two layers, a first coating layer 24a and a second coating layer 24b. Accordingly, since the thickness or volume respectively required for the base paper 23 and the coating 24 can be shared among a plurality of layers, the degree of freedom in the design or manufacture of the base sheet 21 and the microneedle patch 10 is increased.

[0083] Since each layer of the base paper 23 has a thickness of 25 μm or more, the base paper 23 is not excessively flexible. Accordingly, in the manufacturing process of the microneedle patch 10, it is easy for a manufacturing worker to handle the base paper 23.

[0084] (6) Modification Hereinafter, a modification of the first embodiment will be described.

[0085] (6-1) First Modification In the above-described embodiment, in the adhesive tape 20, a first set S1 and a second set S2 having the same laminated structure are stacked. Alternatively, the base sheet 21 may be configured by only the first set S1 without repeating the same laminated structure.

[0086] FIG. 7 shows the configuration of an adhesive tape 20 according to the first modification of the first embodiment. The adhesive tape 20 includes a single-layer base paper 23, a single-layer coating 24, and an adhesive layer 25. Similarly to the above-described embodiment, the thickness of the adhesive tape 20 is 1 mm or less, preferably 500 μm or less. The thickness of the base paper 23 composed of a single layer is 25 μm or more. The weight of the coating 24 per unit area of the base paper 23 is 0.5 g / m ２ or more.

[0087] With this configuration also, the adhesive tape 20 that exhibits a water vapor transmission rate of 40 (g / m ２ / day) or less and exhibits sufficient water vapor barrier performance can be formed of a material that is easily biodegradable.

[0088] (6-2) Second Modification In the above embodiment, the first coating layer 24a is arranged only on one side of the first base paper layer 23a, and the second coating layer 24b is arranged only on one side of the second base paper layer 23b. Alternatively, the coating 24 may be arranged on both sides of the base paper 23.

[0089] Figure 8 shows the configuration of the adhesive tape 20 according to a second modification of the first embodiment. A first coating layer 24a is arranged on one side of a single layer of base paper 23, and a second coating layer 24b is arranged on the other side of the base paper 23. Part or all of the volume of the first coating layer 24a and the second coating layer 24b may penetrate into the base paper 23. Similar to the embodiment described above, the thickness of the adhesive tape 20 is 1 mm or less, preferably 500 μm or less. The thickness of the single layer of base paper 23 is 25 μm or more. The weight of the coating 24 per unit area of ​​the base paper 23, in other words, the sum of the weights of the first coating layer 24a and the second coating layer 24b per unit area of ​​the adhesive tape 20 is 0.5 g / m². ２ That's all.

[0090] This configuration also allows for the construction of an adhesive tape 20 that exhibits sufficient water vapor barrier performance, using biodegradable materials.

[0091] (6-3) Third Modification In the above-described embodiment, in the first set S1, the adhesive layer 25 is in contact with the first base paper layer 23a, and in the second set S2, the intermediate adhesive layer 25b is in contact with the second base paper layer 23b. Alternatively, the adhesive layer 25 may be in contact with the coating 24.

[0092] Figure 9 shows the configuration of the adhesive tape 20 according to a third modification of the first embodiment. A single-layer coating 24 is in contact with the adhesive layer 25. A single-layer base paper 23 is in contact with the coating 24 and is separated from the adhesive layer 25. Similar to the above-described embodiment, the thickness of the adhesive tape 20 is 1 mm or less, preferably 500 μm or less. The thickness of the single-layer base paper 23 is 25 μm or more. The weight of the coating 24 per unit area of ​​the base paper 23 is 0.5 g / m². ２ That's all.

[0093] This configuration also allows for the construction of an adhesive tape 20 that exhibits sufficient water vapor barrier performance, using biodegradable materials.

[0094] (6-4) Fourth Modified Example In the above embodiment, the adhesive tape 20 consists of two sets, a first set S1 and a second set S2, which have the same laminated structure. Alternatively, the adhesive tape 20 may be composed of three or more sets that have the same laminated structure.

[0095] Figure 10 shows the configuration of the adhesive tape 20 according to a fourth modification of the first embodiment. The adhesive tape has a first set S1, a second set S2, and a third set S3. The first set S1 has a first base paper layer 23a, a first coating layer 24a, and an adhesive layer 25. The second set S2 has a second base paper layer 23b, a second coating layer 24b, and an intermediate adhesive layer 25b. The third set S3 has a third base paper layer 23c, a third coating layer 24c, and an intermediate adhesive layer 25c.

[0096] Similar to the embodiments described above, the thickness of the adhesive tape 20 is 1 mm or less, preferably 500 μm or less. The sum of the thicknesses of the first base paper layer 23a, the second base paper layer 23b, and the third base paper layer 23c is 25 μm or more. The weight of the coating 24 per unit area of ​​the base paper 23, in other words, the sum of the weights of the first coating layer 24a, the second coating layer 24b, and the third coating layer 24c per unit area of ​​the adhesive tape 20 is 0.5 g / m². ２ That's all.

[0097] This configuration also allows for the construction of an adhesive tape 20 that exhibits sufficient water vapor barrier performance, using biodegradable materials.

[0098] (6-5) Fifth Modification The embodiments described above and the multiple modifications described above may be combined. For example, a first set S1, a second set S2, and a third set S3 having the same laminated structure as the third modification shown in Figure 9 can be created and stacked to form the adhesive tape 20.

[0099] <Second Embodiment> (1) The schematic diagram 11 shows the schematic configuration of the microneedle patch 10 of the second embodiment and its modified form. This microneedle patch 10 differs from the first embodiment in that it does not have a base portion 31 that connects a plurality of microneedles 32 to each other.

[0100] Figure 12 shows a schematic configuration of a product unit 90 for distributing the microneedle patch 10 of this embodiment and its modified form as a commercial product. The product unit 90 comprises the microneedle patch 10 and a protective sheet 80. The protective sheet 80 is for protecting the multiple microneedles 32 during the distribution process. Each of the multiple microneedles 32 is individually fixed to the base sheet 21. The user peels off the protective sheet 80 immediately before use to expose the multiple microneedles 32.

[0101] Figure 13 shows the basic concepts common to this embodiment and its modifications. The microneedle patch 10 has an adhesive tape 20 and a plurality of microneedles 32. The materials of the base paper 23, coating 24, adhesive layer 25, and the plurality of microneedles 32 are the same as those described in the first embodiment. Similar to the first embodiment and its modifications, the base paper 23 may consist of a single layer or multiple layers. The coating 24 may consist of a single layer or multiple layers.

[0102] Figure 14 shows the specific configuration of the microneedle patch 10 of the second embodiment. The adhesive tape 20 used in this embodiment has the same configuration as in the first embodiment. In the adhesive tape 20, a first set S1 and a second set S2 having the same configuration are stacked on top of each other.

[0103] (2) Features In this embodiment as well, the adhesive tape 20 is manufactured based on a paper called base paper 23. The base paper 23 that provides the base is made of plant-derived materials and contains biodegradable plant fibers. Therefore, the amount of plastic discharged when the microneedle patch 10 is disposed of can be reduced, thereby reducing the burden on the environment.

[0104] (3) Modifications At least one modification of the first embodiment may be applied to this embodiment.

[0105] <Conclusion> The scope of this disclosure is not limited to the embodiments and modifications described herein, and various modifications are possible without departing from the gist of the disclosure. The multiple embodiments and modifications described herein can be combined as needed.

[0106] 10: Microneedle patch 20: Adhesive tape 21: Base sheet 23: Base paper 23a: First base paper layer 23b: Second base paper layer 23c: Third base paper layer 24: Coating 24a: First coating layer 24b: Second coating layer 24c: Third coating layer 25: Adhesive layer 25b: Intermediate adhesive layer 25c: Intermediate adhesive layer 29a: First penetration area 29b: Second penetration area 30: Microneedle sheet 31: Base 32: Microneedle 80: Protective sheet 90: Product unit H: Microneedle height R1: Support area R2: Contact area S1: First set S2: Second set S3: Third set T: Thickness of adhesive tape

Claims

1. A microneedle patch (10) comprising an adhesive tape (20) and a plurality of microneedles (32), wherein the adhesive tape (20) has a base sheet (21) and an adhesive layer (25) for fixing the plurality of microneedles to the base sheet (21), and the base sheet (21) has a base paper (23) and a coating (24).

2. The microneedle patch according to claim 1, further comprising a base portion (31) formed integrally with the plurality of microneedles and connecting the plurality of microneedles.

3. The microneedle patch according to claim 2, wherein the base paper contains plant fibers.

4. The microneedle patch according to claim 3, wherein the base paper comprises at least one of glassine paper, white paper, kraft paper, Japanese paper, newsprint paper, parchment paper, rice paper, matte paper, and unmodified cellophane.

5. The microneedle patch according to claim 3, wherein the base paper is glassine paper.

6. The microneedle patch according to claim 3, wherein the coating is a natural wax or natural resin of plant or animal origin.

7. The microneedle patch according to claim 6, wherein the natural wax comprises at least one of carnauba wax, candelilla wax, Japanese wax, rice wax, sugarcane wax, soy wax, palm wax, jojoba wax, sunflower wax, and beeswax, and the natural resin comprises shellac.

8. The microneedle patch according to claim 6, wherein the coating is carnauba wax.

9. The microneedle patch according to any one of claims 1 to 8, wherein the base sheet (21) has one or more layers of base paper (23), and the sum of the thicknesses of all layers of base paper (23) in the base sheet (21) is 25 μm or more.

10. The base sheet (21) has one or more layers of the coating (24), and in the base sheet (21), the weight of the one or more layers of the coating (24) per unit area of ​​the base paper (23) is 0.5 g / m². ２ The above is the microneedle patch according to claim 9.

11. The microneedle patch according to claim 10, wherein the base paper (23) has at least a first base paper layer (23a) and a second base paper layer (23b), and the coating (24) has at least a first coating layer (24a) in contact with the first base paper layer and a second coating layer (24b) in contact with the second base paper layer, and at least one of the first coating layer (24a) or the second coating layer (24b) is disposed between the first base paper layer (23a) and the second base paper layer (23b).

12. The microneedle patch according to claim 11, further comprising an intermediate adhesive layer (25b) disposed between the first base paper layer (23a) and the second base paper layer (23b).

13. The microneedle patch according to claim 12, wherein the first base paper layer (23a) is in contact with the adhesive layer (25), the first coating layer (24a) is in contact with the first base paper layer (23a), the intermediate adhesive layer (25b) is in contact with the first coating layer (24a), the second base paper layer (23b) is in contact with the intermediate adhesive layer (25b), and the second coating layer (24b) is in contact with the second base paper layer (23b).

14. The microneedle patch according to claim 11, wherein both the first base paper layer (23a) and the second base paper layer (23b) have a thickness of 25 μm or more.

15. The microneedle patch according to any one of claims 1 to 8, wherein the adhesive layer can come into contact with the user's skin, thereby allowing the plurality of microneedles to penetrate the skin.

16. The microneedle patch according to claim 15, wherein the plurality of microneedles are composed of a substance that is biosoluble or biodegradable.

17. The adhesive tape (20) has a density of 40 g / m ２ A microneedle patch according to any one of claims 1 to 8, exhibiting a water vapor transmission rate of less than or equal to / day.

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