Self-generating skin patch containing biodegradable metal

Abstract

The self-current-generating skin-applied patch includes a first region that contacts the user's skin and a second region that is spaced apart from the first region and contacts the adjacent skin that the first region contacts. The first region or the second region contains a biodegradable metal that contacts the user's skin or reacts with moisture in tissue to be decomposed and absorbed. The first region or the second region is provided as a thin sheet-like structure integral with the first region that directly contacts the user's skin and has at least one penetration that allows fluid delivery from the side opposite to the skin contact; a second electrode layer made of a different material that has a different standard reduction potential from the material that makes up the first electrode layer, located on the side opposite to the skin contact of the first electrode layer while being insulated from the first electrode layer, and at least a portion of the second electrode layer extends to be electrically connected to the second region; and a carrier layer that is a thick sheet-like layer located on the side opposite to the skin contact of the first electrode layer and is made of a hydrophilic material that can carry an ionic solution. The self-generated microcurrent can provide sufficient iontophoresis of active ingredients and other microcurrent effects even without a separate power source such as a battery.

Description

[Technical Field]

[0001] The present invention relates to a skin-applied patch for delivering cosmetic or pharmaceutical active ingredients into the body, and more specifically to a self-current-generating skin-applied patch containing a biodegradable metal, which is configured so that a microcurrent is generated simply by applying it to the skin due to the oxidation-reduction potential difference between different metals in an ionic solution consisting of the active ingredient or a mixture of the active ingredient, and which can provide beneficial effects through the decomposition action of the biodegradable metal at the contact site. [Background technology]

[0002] Generally, in the transdermal method of delivering active ingredients into the body through the skin, the most common method is to apply a cream or gel-type product containing the active ingredient in a formulated form to the surface of the skin. However, a considerable amount of the active ingredient is generally wasted because it is unable to penetrate into the tissue compared to the amount applied. In particular, when the active ingredient has a large three-dimensional size, such as a high molecular weight material, there is a problem in that most of it is unable to pass through not only the epidermis but also the stratum corneum of the skin.

[0003] The most direct transdermal method to solve this problem is to inject the active ingredient via injection. This method has the advantage of being rapidly absorbed into the tissues and having an immediate effect because the drug is directly injected into the body by inserting a needle through the skin. However, it is troublesome because it must be administered by a specialist (making self-administration difficult), and the needle usually reaches several millimeters in length and has a diameter of several millimeters, which leads to poor patient compliance due to the pain of the injection.

[0004] There has been a great deal of effort in developing transdermal drug delivery systems to minimize the above-mentioned side effects and drawbacks.

[0005] As mentioned above, active ingredients that are absorbed through the skin are usually formulated in the form of liquids, creams, gels, etc. However, liquids, creams, and gels have problems such as difficulty in adjusting the dosage due to the characteristics of the formulation, stickiness, and the coating becoming dirty.

[0006] Therefore, a method is used in which a patch containing an active ingredient is attached to the skin to allow the active ingredient to be absorbed through the skin.

[0007] The method of administering active ingredients such as drugs using a patch allows the drug to be absorbed through the skin, preventing side effects associated with oral drug administration, such as gastrointestinal disorders and food effects, and eliminating the pain and inconvenience of injections. Due to this convenience, the use of patches has been gradually increasing recently.

[0008] Broadly speaking, patches can be composed of a drug-impermeable backing layer that prevents the passage of the active drug ingredient, a drug-permeable membrane, and an adhesive layer that adheres the patch to the skin, and a storage space in which the drug is stored is provided between the backing layer and the drug-permeable membrane.

[0009] A major drawback of such patches is that the absorption rate of active ingredients through the skin is low, so the skin's function as a permeability barrier must be reduced. Generally, the absorption rate through patches is known to be around 20%.

[0010] Various methods have been used to increase the rate of dermal absorption of active ingredients such as drugs, including chemical methods such as the use of skin absorption enhancers and prodrugs, and physical methods such as iontophoresis and electrophoresis.

[0011] However, even when these known methods are used, there is still a limit to how much the absorption rate of the active ingredient can be improved to a satisfactory level, and therefore, in order to expect an effect, it is unavoidable to use an amount of the active ingredient that is in excess of the amount actually required, taking into account the absorption rate.

[0012] In particular, the type of skin absorption enhancer is determined depending on the design type of the formulation to be used or the physicochemical properties of the components, and a certain concentration level or higher is required to be effective. However, when a skin absorption enhancer is added, it is difficult to prevent crystal formation over time, and adhesive properties such as adhesive strength and cohesive strength change over time to make the enhancer unsuitable for use.

[0013] In addition, technologies that use electricity require the patch to have batteries, electrodes, circuits, and other components, which makes the product structure complicated, large in size, and expensive, and also generates a large amount of waste after use.

[0014] The present applicant has been continuously researching and developing technology for microneedle patches made of biodegradable metals as a transdermal active ingredient delivery system, and has previously disclosed technologies that increase the transdermal active ingredient delivery efficiency and have beneficial effects that occur during the decomposition process itself through Patent Document 1: Korean Patent Registration No. 2114472 "Microneedles using biodegradable metals" and Patent Document 2: Korean Patent Registration No. 2291392 "Multi-type microneedles".

[0015] These technologies already provide excellent transdermal drug delivery means through the use of microneedles that effectively penetrate the stratum corneum and epidermis without stimulating the pain-sensing nerves of the human body, and through a unique structure in which multiple microneedles are arranged around a hole. However, the applicant has not stopped there, and has further researched and developed a method that can deliver active ingredients deep into the skin in a short period of time, leading to the present invention.

[0016] Therefore, the present applicant has proposed the present invention to solve the above-mentioned problems. Related prior art documents include Patent Document 3: Korean Patent Registration No. 10-1423241, entitled "Microcurrent Generating Patch," and Patent Document 4: Korean Patent Registration No. 10-2390735, entitled "Microcurrent Generating Patch for Transdermal Drug Delivery and Manufacturing Method Thereof." However, Korean Patent Registration No. 10-1423241 only describes the structure and effect of promoting metabolism and blood circulation in the affected area by microcurrent generated by a metal of different materials and a gel-like adhesive layer, while Korean Patent Registration No. 10-2390735 only discloses a drug penetration structure using an iontoporesis method, but only presents a conceptual structure of the iontoporesis patch and does not provide any specific alternative for achieving a sufficient iontoporesis effect using self-generated power without a separate power source, nor does it propose an optimized structure, such as microneedles made of biodegradable metal, or any synergistic effects resulting therefrom. [Prior art documents] [Patent documents]

[0017] [Patent Document 1] Korean Patent Registration No. 10-2114472 [Patent Document 2] Korean Patent Registration No. 10-2291392 [Patent Document 3] Korean Patent No. 10-1423241 [Patent Document 4] Korean Patent No. 10-2390735 [Non-patent literature]

[0018] [Non-Patent Document 1] YOON, KS et al., Histological study on the effect of electrolyzed reduced water-bathing on UVB radiation-induced skin injury in hairless mice, Biological and Pharmaceutical Bulletin 34, 1671-7, 2011 [Non-patent document 2] IGNACIO, RM, et al., The balneotherapy effect of hydrogen reduced water on UVB-mediated skin injury in hairless mice, Molecular & Cellular Toxicology 9, 15-21, 2013 Summary of the Invention [Problem to be solved by the invention]

[0019] The present invention aims to solve these problems by providing a self-current generating skin patch containing a biodegradable metal that can generate a microcurrent without a separate power source such as a battery, thereby maximizing the effect of delivering active ingredients to the body through iontophoresis, and simultaneously providing the microcurrent effect known to relieve pain while repairing damage to nerves, muscles, and tissues.

[0020] Another object of the present invention is to provide a self-current generating skin application patch that has skin improving effects and drug delivery enhancing effects due to the decomposition products and hydrogen gas released during decomposition by applying a biodegradable metal of a specific composition according to the present invention to the electrodes and skin contact portion.

[0021] Another object of the present invention is to provide a self-current generating skin application patch that not only increases the keratinocyte permeability through the microneedles at the contact point with the user's skin, but also reduces the skin resistance value at the application site, thereby significantly enhancing the internal delivery effect of active ingredients through iontophoresis. [Means for solving the problem]

[0022] In order to achieve the above object, the self-current generating skin-applied patch according to the present invention comprises a first region that contacts the user's skin and a second region that is spaced apart from the first region and contacts the adjacent skin that the first region contacts, wherein the first region or the second region contacts the user's skin or contains a biodegradable metal that can be decomposed and absorbed by reacting with moisture in tissue, and the first region or the second region is provided integrally with the first region in the form of a thin sheet that directly contacts the user's skin and has at least one through-hole that allows fluid delivery from the side opposite to the skin contact; a second electrode layer made of a different material that has a standard reduction potential different from that of the first electrode layer, located on the side opposite to the skin contact of the first electrode layer while being insulated from the first electrode layer, and at least a portion of which extends to be electrically connected to the second region; and a carrier layer in the form of a thick sheet that is located on the side opposite to the skin contact of the first electrode layer and made of a hydrophilic material that can carry an ionic solution.

[0023] In this case, the first region or the second region may include at least one microneedle protruding in a direction of contact with the user's skin.

[0024] In this case, the biodegradable metal is represented by the following chemical formula 1.

[0025] [Chemical formula 1] Mg a Zn b Ca c X d

[0026] (wherein a, b, c, and d are the weight percentages of each component, a+b+c+d=100 weight%, a is the largest, 0≦b≦5, 0≦c≦1, 0≦d≦1, and X is one or more members of an impurity group consisting of elements other than Mg, Zn, and Ca.)

[0027] In this case, the first region and the first electrode layer may be a biodegradable metal according to Chemical Formula 1, and the second electrode layer may include a different substance having a higher standard reduction potential than the first electrode layer.

[0028] Meanwhile, the second electrode layer may be made of one or more materials selected from copper, zinc, silver, silver chloride, iron, and stainless steel.

[0029] In this case, the second region may be a biodegradable metal represented by Chemical Formula 1 and configured to be electrically connected to the portion extending from the second electrode layer.

[0030] Meanwhile, the second electrode layer may be a biodegradable metal according to Chemical Formula 1, and the first electrode layer may be configured to include a different substance having a higher standard reduction potential than the second electrode layer.

[0031] In this case, the microneedles preferably have a length of 0.02 mm or more.

[0032] Meanwhile, the support layer may be positioned in a laminated form between the first electrode layer and the second electrode layer.

[0033] The first electrode layer and the second electrode layer are stacked while being insulated from each other by an insulating layer, the second electrode layer has an opening that exposes at least a portion of the through-portion of the first electrode layer, and the support layer can be configured to be positioned in a form that covers at least a portion of the opening on the side opposite to the skin contact side of the first electrode layer.

[0034] In this case, the through-hole formed in the first electrode layer may be hole-shaped, and at least one of the microneedles may be formed by bending along the edge of the hole in a direction that contacts the user's skin.

[0035] Meanwhile, the second electrode layer can be applied in the form of a flexible fabric made including conductive fibers.

[0036] Meanwhile, the ionic solution contains one or more selected from phosphate buffered saline and aqueous sodium chloride solution, and may further contain at least one active ingredient of functional cosmetics and pharmaceuticals.

[0037] In this case, the active ingredient may be composed of an ionic substance.

[0038] Meanwhile, the support layer may be one or more selected from the group consisting of a pure cotton sheet, a natural pulp sheet, and a rayon sheet, which are materials in the form of dried fabric.

[0039] The device may further include a capsule that causes the carrier layer to eject the ionic solution upon user-initiated action.

[0040] On the other hand, the area of ​​the first region is preferably at least twice the area of ​​the second region.

[0041] Meanwhile, the first region formed integrally with the first electrode layer may be in the form of a thin sheet having a thickness of 0.07 to 0.7 mm. [Effects of the Invention]

[0042] The self-current generating skin application patch containing a biodegradable metal according to the present invention has the following effects due to the above-mentioned configuration.

[0043] First, even without a separate power source such as a battery, sufficient iontophoresis of active ingredients and other microcurrent effects can be achieved by self-generated microcurrents.

[0044] Second, by using the magnesium-based biodegradable metal according to Chemical Formula 1 of the present invention, which can be decomposed by contact with the skin or in tissues, as a material for the skin-contact electrode, the delivery effect of the active ingredient can be further enhanced by the decomposition products, which act as drug delivery enhancers.

[0045] Thirdly, the by-products and hydrogen gas generated during the decomposition process can provide additional benefits such as wrinkle improvement, reduction of skin erythema caused by inflammation, and prevention of skin damage caused by the sun.

[0046] Fourth, the micro-scale microneedles in the user skin contact area not only allow for smoother penetration of the stratum corneum and delivery of active ingredients into the tissue, but also increase the power by reducing the skin resistance value caused by the microneedles, further enhancing the effectiveness of drug delivery by iontophoresis.

[0047] Fifth, by appropriately arranging different metal materials with different mutual standard reduction potentials electrically connected to the first and second regions that come into contact with the skin, it is possible to provide a product that can be used appropriately depending on the anionic / cationic nature of the active ingredient.

[0048] Sixth, biodegradable metals that come into contact with or are inserted into the skin undergo an electrochemical reaction to release more biodegradable metal ions, allowing the damaged skin barrier to heal more quickly. [Brief explanation of the drawings]

[0049] [Figure 1] 1 is a schematic side view of a skin-applied patch according to a first preferred embodiment of the present invention. [Figure 2] FIG. 2 is a schematic side view of a skin-applied patch according to a second preferred embodiment of the present invention. [Figure 3] FIG. 2 is a schematic side view of a skin-applied patch according to a third embodiment, which is a modified example of the first embodiment of FIG. [Figure 4]FIG. 10 is a schematic side view of a skin-applied patch according to a fourth preferred embodiment of the present invention incorporating a pre-field capsule. [Figure 5] 1 is a schematic side view showing the overall structure of a skin application patch according to the present invention, which is attached to the skin by an adhesive sheet. [Figure 6a] FIG. 1 is a diagram showing, on an alloy phase diagram, test pieces corresponding to the composition of biodegradable metals applicable to the present invention. [Figure 6b] FIG. 1 is a diagram showing, on an alloy phase diagram, test pieces corresponding to the composition of biodegradable metals applicable to the present invention. [Figure 6c] FIG. 1 is a diagram showing, on an alloy phase diagram, test pieces corresponding to the composition of biodegradable metals applicable to the present invention. [Figure 6d] FIG. 1 is a diagram showing, on an alloy phase diagram, test pieces corresponding to the composition of biodegradable metals applicable to the present invention. [Figure 6e] FIG. 1 is a diagram showing, on an alloy phase diagram, test pieces corresponding to the composition of biodegradable metals applicable to the present invention. [Figure 6f] FIG. 1 is a diagram showing, on an alloy phase diagram, test pieces corresponding to the composition of biodegradable metals applicable to the present invention. [Figure 6g] FIG. 1 is a diagram showing, on an alloy phase diagram, test pieces corresponding to the composition of biodegradable metals applicable to the present invention. [Figure 6h] FIG. 1 is a diagram showing, on an alloy phase diagram, test pieces corresponding to the composition of biodegradable metals applicable to the present invention. [Figure 7] FIG. 1 is a diagram schematically illustrating an experiment using the electrodes used in the experiment of the present invention. [Figure 8] This figure shows experimental conditions comparing copper and SUS301 as positive electrodes in a PBS solution. [Figure 9] FIG. 1 shows experimental conditions comparing copper and SUS301 as positive electrodes in a NaCl solution. [Figure 10] FIG. 1 is a perspective view showing the shapes of microneedles and penetrating parts that can be applied to the first region of the present invention. [Figure 11]Figure 11 (a) to (c) are photographs of prototype skin-applied patches according to the present invention, with no microneedles, with 100 μm-long needles, and with 230 μm-long needles, respectively. [Figure 12] FIG. 1 is a perspective view of a skin-applied patch according to the present invention in a manufactured form, provided with an adhesive sheet and a release liner. [Figure 13] FIG. 13 is an enlarged view of the patch product at the bottom of FIG. 12. [Figure 14] FIG. 10 is an exploded perspective view of a skin-applied patch according to a sixth preferred embodiment of the present invention. [Figure 15] 15 is a photograph showing the state of adhesion to the skin of a prototype product that realizes a skin-applied patch according to the embodiment of FIG. 14. [Figure 16] From the left, the photographs show patch samples with a copper thin plate as the second electrode plate, a 65 μm thick Ag / AgCl coating layer on a PET film, and a 130 μm thick Ag / AgCl coating layer on a PET film. DETAILED DESCRIPTION OF THE INVENTION

[0050] The advantages and features of the above-mentioned configuration of the present invention, as well as the methods for achieving them, will become apparent from the following detailed description of the embodiments in conjunction with the accompanying drawings.

[0051] However, the present invention is not limited to the embodiments disclosed below, but may be realized in various different forms. The present embodiments are provided merely to complete the disclosure of the present invention and to fully convey the scope of the invention to those skilled in the art to which the present invention pertains. The present invention is defined only by the scope of the claims.

[0052] The present invention is based on a structure in which the part that comes into contact with the user's skin is made of a conductive metal material or other conductive substance, which is composed of two or more areas spaced apart from each other, and a minute current is generated due to the potential difference that occurs between the two areas.

[0053] For this reason, the patch according to the present invention has the configuration of a voltaic cell, which is the most basic battery configuration.

[0054] That is, for the negative electrode (-), a metal material (material with a low standard reduction potential) that has a high ionization tendency and easily becomes a positive ion can be used, and in the present invention, it is basically a magnesium-based material, the details of which will be described later.

[0055] On the other hand, a conductive material with low ionization tendency (a material with a high standard reduction potential) can be used for the positive electrode (+), and the structure allows an electrolyte capable of ion exchange to be placed between them.

[0056] The solution that functions as the electrolyte is referred to as an "ionic solution" in the present invention, and can be provided so as to be supported on a support layer made of a dry fabric-like material that can support the solution, such as a pure cotton sheet, a natural pulp sheet, or a rayon sheet.

[0057] That is, the metal of the negative electrode plate is ionized into positive ions by the ionic solution carried by the support layer, releasing electrons. The released electrons then travel through the human tissue to the positive electrode plate, generating a minute current. At this time, the generated current acts as an electrolyte, enabling the active ingredients in the ionic solution containing the active ingredients to be delivered quickly and deeply into the subcutaneous tissue.

[0058] The active ingredient may penetrate and diffuse into the subcutaneous tissue together with the ionic solution during the penetration and diffusion process, or may be transported by a direct electrical force due to its own negative or positive ionic nature.

[0059] That is, when an active ingredient having negative ionic properties is supplied when the negative electrode metal is in contact with the skin, or when an active ingredient having positive ionic properties is supplied when the negative electrode metal is in contact with the skin, the delivery and diffusion effect of the active ingredient by electrical force can be maximized. For this reason, the present invention exemplifies two main forms of embodiments and their corresponding modifications, and proposes additional embodiments other than these.

[0060] FIG. 1 is a schematic side view of a self-current generating skin-applied patch containing a biodegradable metal according to a first preferred embodiment of the present invention. The first electrode layer 11, which constitutes the first region 10 that contacts the user's skin and acts as a negative electrode, has a magnesium-based composition represented by chemical formula 1 according to the present invention, which will be described later. The second electrode layer 22, which is separated from the first electrode layer 11 by a support layer 30, can be made of a material that has a lower ionization tendency and a higher standard reduction potential than the first electrode layer 11, such as copper, zinc, silver, silver chloride, iron, or stainless steel.

[0061] In this state, when the first region 10 and the second region 20 extending from the second electrode layer 22 come into contact with the user's skin, and an ionic solution acting as an electrolyte is carried on the support layer 30 interposed between the first electrode layer 11 and the second electrode layer 22, which were previously electrically insulated by the support layer 30, the metal of the first electrode layer is ionized, causing electrons to move through the skin, i.e., generating a current.

[0062] In this case, if the active ingredient contained in the ionic solution carried in the carrying layer 30 has negative ionicity, the delivery and diffusion of the active ingredient supplied to the skin below the first region 10 through the penetration portion 16 can occur more effectively due to the iontophoresis action.

[0063] Conversely, when the active ingredient contained in the ionic solution has positive ionicity, it is preferable that the difference in standard reduction potential between the first electrode layer 11 and the second electrode layer 22 be opposite to that in the first embodiment.

[0064] That is, Figure 2 is a schematic side view of a self-current generating skin-applied patch containing a biodegradable metal according to a second preferred embodiment of the present invention. Unlike the first embodiment, the first electrode layer 11 constituting the first region 10 that contacts the user's skin acts as a positive electrode and can be made of a material that has a lower ionization tendency and a higher standard reduction transition than the second electrode layer 22 having a magnesium-based composition represented by Chemical Formula 1 according to the present invention described below, such as copper, zinc, silver, silver chloride, iron, stainless steel, etc.

[0065] In this state, if the active ingredient contained in the ionic solution held in the support layer 30 has positive ionicity, the delivery and diffusion of the active ingredient by iontophoresis supplied to the skin below the first region 10 through the penetration portion 16 can occur more effectively than in the case of an active ingredient that is electrically neutral or has negative ionicity.

[0066] Due to the clear distinction between these two types, in the present invention, the first embodiment is named the basic type, and the second embodiment is named the reverse type.

[0067] As a variation of the first embodiment, a patch as shown in FIG. 3 may be provided.

[0068] In the first embodiment as the basic type, the second region 20 is simply structured so that the portion extending from the second electrode layer 22 comes into direct contact with the skin, and therefore in this embodiment, the second region 20 simply serves as an electrode for iontophoresis and microcurrents.

[0069] However, even though it is a basic type, as in the third embodiment shown in Figure 3, when a biodegradable metal having a magnesium-based composition according to Chemical Formula 1 described below is bonded to form the second region 20 in the skin contact direction of the second electrode layer 22 that serves as the positive electrode, there is an advantage in that the beneficial effects obtained during the metal decomposition process can be obtained over the entire area of ​​the patch.

[0070] Meanwhile, the structure of a self-current generating skin-applied patch containing a biodegradable metal according to a fourth embodiment of the present invention shown in FIG. 4 will be described.

[0071] As described above, the support layer 30 of the present invention may be provided in a state where no ionic solution is carried thereon, so that an ionic solution containing an active ingredient is supplied through the through-hole 16 or side portion of the first region 10.

[0072] In other words, in this case, the patch according to the present invention and an ampoule containing the active ingredient can be provided separately as a set, and the user can allow the solution in the ampoule to be absorbed into the carrier layer 30 immediately before applying it to the skin.

[0073] However, in order to eliminate such inconveniences in use, the patch according to the fourth embodiment, which is a modification of the basic third embodiment, may have a separate capsule 40 contained within the volume of the carrier layer 30 or located adjacent to it, and may have a structure in which an ionic solution containing an active ingredient is stored within the capsule 40.

[0074] In this case, the user can pull the handle 41 connected to the capsule 40 to cause the ionic solution in the capsule 40 to be ejected into the carrier layer 30 .

[0075] The patches according to the present invention exemplified as the first to fourth embodiments can be attached in close contact with the user's skin by the adhesive sheet 50 as shown in FIG. 5, and can be provided in a commercial form in which the adhesive sheet 50 and release paper are provided together as shown in FIGS. 12 and 13.

[0076] 13 is an enlarged view of the patch product at the bottom of FIG. 12, and is depicted transparently so that the positional relationship between each component can be seen. It can be seen that the first region 10, which is formed over a large area and has numerous holes for the through-holes 16, is formed as the first electrode layer 11, and a portion of the second electrode layer 22, which is disposed between the first electrode layer 11 and the support layer 30, extends to the right from a position overlapping the first region 10, and the extension is bonded to a thin microneedle plate corresponding to the second region 20, which is smaller in area than the first region 10.

[0077] Here, we will explain in detail the biodegradable metal of the present invention that can be applied to the first electrode layer 11 and first region 10 in embodiment 1, the second electrode layer 22 and second region 10 in embodiment 2, and the first electrode layer 11, first region 10, and second region 20 in embodiment 3.

[0078] The biodegradable metal according to the present invention can be defined by the following chemical formula 1.

[0079] [Chemical formula 1] Mg a Zn b Ca c X d

[0080] In the formula, a, b, c, and d are the weight percentages of each component, and a+b+c+d=100 weight%, a is the largest and therefore has a value of 0 or more and 100 or less, while 0≦b≦5, 0≦c≦1, 0≦d≦1, and X can be one or more of an impurity group consisting of elements other than Mg, Zn, and Ca.

[0081] That is, the biodegradable metal according to the present invention encompasses metals that react with water in the body and decompose, but specifically, magnesium is the main component, to which zinc and calcium are mixed in appropriate proportions to provide harmless and beneficial effects to the human body, and can be selected from compositions with various alloy phases and decomposition rates.

[0082] Figures 6a-6h show the internal phases of alloys at specific temperatures depending on the magnesium, zinc, and calcium content. Depending on the content, these alloys exist in various states, including alpha magnesium phase (HCP), ternary phase (Ca2Mg6Zn3), Mg2Ca (C14_b), and MgZn. The Mg2Ca phase not only increases the strength of the alloy but also increases the decomposition rate by forming a galvanic circuit. The MgZn phase also increases the decomposition rate by inducing micro-galvanics within the alloy. In other words, an increase in the decomposition rate indicates a higher degree of ionization compared to pure Mg, which is expected to increase the electromotive force due to the difference in standard reduction potential with the positive electrode layer.

[0083] Using specimen 3 (Figure 6c) as an example, an alloy in a liquid state at a casting temperature of approximately 650°C or higher passes through a region where alpha-magnesium (HCP) and liquid phases coexist, a region where alpha-magnesium (HCP) phases are formed, and a region where alpha-magnesium (HCP) and ternary (Ca2Mg6Zn3) phases are formed. At this point, the alloy structure is determined by the alpha-magnesium (HCP) and ternary (Ca2Mg6Zn3) phases, preventing the formation of the MgZn phase at the lower end. If the MgZn phase were to be intentionally formed with the composition of specimen 3, the alloy would need to be heat-treated for a long period of time at a temperature below approximately 120°C. However, in a typical casting furnace, the alloy is removed from the casting furnace and rapidly cooled before it reaches the temperature at which the MgZn phase forms, preventing the formation of the MgZn phase.

[0084] On the other hand, the impurities include Ce, Mn, Al, Pb, Fe, Ni, Zr, Cu, Th, Be, Cd, Sn, P, Si, La, Sr, Pr, Na, Y, etc., which flow in from the crucible during the manufacturing process, and the total amount thereof is preferably 1 wt % or less.

[0085] In the present invention, the biodegradable metal can be produced by melt-mixing magnesium, calcium, and zinc, followed by molding, as is commonly known.

[0086] The melting can be carried out in an inert gas atmosphere such as argon (Ar) which does not react with magnesium, calcium, and zinc, or in a vacuum atmosphere. Various methods can be used, such as a resistance heating method in which heat is generated by applying electricity to a resistor, an induction heating method in which current is passed through an induction coil, or a method using a laser or focused light.

[0087] Examples of the forming method include, but are not limited to, a cooling method, an extrusion method, a metal processing method, etc. The cooling method can be used to improve the mechanical strength of the magnesium alloy. More specifically, a method of immersing a crucible containing molten magnesium in water can be used. Alternatively, a cooling method of spraying the molten magnesium using an inert gas such as argon can be used. The spray cooling method can be used to cool at a much faster rate and produce a very fine structure. However, care should be taken when casting magnesium into small sizes, as many pores may be formed inside.

[0088] By using such a processing method, a magnesium-based alloy can be produced in a form containing a composition and crystalline phase suitable for generating a desired level of electromotive force. For example, as a method for further increasing the electromotive force when using the same electrode, a galvanic circuit can be configured to increase the decomposition rate, thereby forming an alloy containing a high-strength MgCa phase.

[0089] <Example> [Production of biodegradable metal test strips]

[0090] Calcium, zinc, and magnesium according to the composition shown in Table 1 below were placed in a stainless steel (SUS410) (or carbon) crucible with an inner diameter of 50 mm. Next, argon gas was passed around the crucible to prevent the calcium, zinc, and magnesium in the crucible from coming into contact with air. The crucible temperature was raised to approximately 700°C to 750°C using a resistance heating furnace to melt the calcium, zinc, and magnesium. The materials in the crucible were stirred to ensure thorough mixing of the molten calcium, zinc, and magnesium. The completely molten magnesium alloy was cooled to produce a solid magnesium alloy. During cooling, the crucible was immersed in water to rapidly cool the molten magnesium alloy, thereby improving its mechanical strength.

[0091] The solid-state magnesium alloy was extruded to produce test specimens. The extrusion temperature was 400°C, and the cross-sectional area reduction ratio before and after extrusion (extrusion ratio) was set to 40:1. The composition of the produced test specimens was evaluated using a metal component analyzer (SPECTRO MAXx), and the results are shown in Figures 6(a) to 6(h) and Table 1.

[0092] [Table 1]

[0093] The prepared test piece was then placed in a heating furnace and further heat-treated at 450° C. for 24 hours to prepare a heat-treated biodegradable metal test piece.

[0094] [Evaluation of biodegradable metals]

[0095] The decomposition characteristics of some of the heat-treated biodegradable metal test specimens prepared as described above were evaluated. To evaluate the decomposition characteristics, the amount of hydrogen gas released during decomposition was measured using a eudiometer in a PBS solution set at 37°C, taking into account the characteristic that alkaline earth metals release hydrogen gas when decomposed. The results are shown in Table 4.

[0096] [Table 2]

[0097] From Table 2, by comparing the test specimens prepared in the examples with commercially available biodegradable alloy materials as comparative examples, it can be seen that there is a diverse spectrum of test specimens with high and low decomposition rates based on the commercially available biodegradable alloy materials. Therefore, it is possible to selectively apply a magnesium-based alloy composition with an appropriate decomposition rate depending on the active ingredients, application period, etc. of the skin application patch provided by the present invention.

[0098] Since the microneedles 15 formed in the first region 10 or the second region 20, which are the contact areas with the user's skin according to the present invention, are manufactured from a biodegradable metal having the composition of Chemical Formula 1, they differ from conventional microneedles in that they are inserted subcutaneously or epidermally to inject an active ingredient, and then function as an electrode, and are absorbed and decomposed to release metal ions and decomposition products into the body.

[0099] Magnesium (Mg), calcium (Ca), zinc (Zn), etc., which are used as materials for the microneedles of the present invention, are alkaline earth metals that are biodegradable and have a mechanism for reacting with water to release hydrogen gas, as shown in the following mathematical formula: Therefore, the metal-based microneedles release ions and decomposition products when absorbed and decomposed subcutaneously, and the hydrogen gas produced as a by-product has a swelling effect subcutaneously, thereby inducing wrinkle improvement, reducing inflammatory skin erythema, and preventing skin damage caused by the sun (Non-Patent Documents 1-2: YOON, KS et al., Histological study on the effect of electrolyzed reduced water-bathing on UVB radiation-induced skin injury in hairless mice, Biological and Pharmaceutical Bulletin 34, 1671-7, 2011; IGNACIO, RM, et al., The balneotherapy effect of hydrogen reduced water on UVB-mediated skin injury in hairless mice, Molecular & Cellular Toxicology 9, 15-21, 2013).

[0100] Mg + 2H2O → Mg(OH)2 + H2(gas)

[0101] Zn + 2H2O → Zn(OH)2 + H2(gas)

[0102] Ca + 2H2O → Ca(OH)2 + H2(gas)

[0103] In addition, ZnO and MgCl, which are by-products of magnesium (Mg) and zinc (Zn) inserted into the body, can act as drug delivery enhancers that improve drug absorption even when present only on the surface of the skin without penetrating subcutaneously. Therefore, needles made of biodegradable metals can further enhance the delivery effect of the active ingredient carried in the patch of the present invention.

[0104] Therefore, as described above, by applying the biodegradable metal to the skin contact site of the skin-applied patch of the present invention, synergistic effects such as beneficial effects of the decomposition products and effects as a drug delivery enhancer can be obtained.

[0105] [Experiment on electromotive force generation depending on the type of electrolyte and the type of metal in the negative electrode]

[0106] Prior to this experiment, a preliminary experiment was conducted to compare the electromotive force generated by PBS and a commercially available acne ampoule solution. However, in the case of acne ampoule solution, the electromotive force did not meet the standard for any of the negative electrode metals. Therefore, it was confirmed that the ionic solution applicable to the present invention must be used in a state where the active ingredient is mixed with a solution with a high degree of ionization as an electrolyte, or an aqueous solution of the active ingredient with a high degree of ionization itself must be used.

[0107] As shown in Figure 7, a pure Mg electrode containing unavoidable impurities was used as the negative electrode, and commercially available phosphate buffered saline (PBS) and an artificially produced 0.9% NaCl aqueous solution were prepared as electrolytes that can be used as the ionic solution of the present invention. Experiments were conducted using SUS301, a type of stainless steel, and copper as the positive electrode metals.

[0108] Such an experiment was carried out as shown in the photographs of FIGS.

[0109] Figure 8 shows the experimental conditions for a comparison between copper and SUS301 as the positive electrode in a PBS solution.

[0110] Figure 9 shows the experimental conditions comparing copper and SUS301 as positive electrodes in a NaCl solution.

[0111] The results are shown in Table 3 below.

[0112] [Table 3]

[0113] Open circuit voltage V oc In addition, a 500Ω resistor was used to measure the operating voltage and current. As a result, it was confirmed that an artificially prepared 0.9% NaCl aqueous solution is more advantageous than PBS as an electrolyte contained in the ionic solution, presumably because there are fewer factors that hinder ion movement within the aqueous solution.

[0114] Meanwhile, in terms of matching for the positive electrode, it was confirmed that the Mg-SUS301 combination was generally more advantageous in terms of electromotive force, but the Mg-Cu combination was also predicted to be sufficient for application to the patch of the present invention. In the human application experiment described below, copper was found to be more advantageous in terms of ductility, which is related to skin adhesion and adhesiveness, so it can be appropriately selected depending on the structure of the patch to be manufactured.

[0115] From the above experiments, it was confirmed that the ionic solution according to the present invention preferably includes an aqueous NaCl solution and other aqueous ionic solutions having a similar degree of ionization. Therefore, the ionic solution according to the present invention can be provided by using an active ingredient solution having a comparable ionization degree, or by mixing the active ingredient with the good electrolyte solution.

[0116] There are no limitations on the active ingredient, so long as it is an ingredient that can produce the effects of functional cosmetics or pharmaceuticals, and active ingredients that have ionic properties are more preferred.

[0117] As an example, functional cosmetics are defined as follows:

[0118] -Functional cosmetics that help whiten skin

[0119] -Functional cosmetics that help improve skin wrinkles

[0120] -Functional cosmetics that help protect the skin from UV rays

[0121] -Functional cosmetics that help change hair color (including desalting and bleaching)

[0122] -Functional cosmetics that help remove body hair

[0123] -Functional cosmetics that help relieve acne-prone skin

[0124] In particular, with regard to the functions of skin whitening (brightening skin tone), wrinkle improvement, and acne-prone skin alleviation, the applicant of the present invention has previously disclosed in publications such as Korean Patent Registration No. 2194089 "Flexible metal patch with antioxidant activity and skin whitening effect and method of using same" and Korean Patent Registration No. 2310566 "Patch for acne alleviation and prevention" that the biodegradable metal according to the present invention exhibits the above-mentioned functional effects by itself without the need for a separate active ingredient. Therefore, a greater synergistic effect can be expected when the biodegradable metal skin patch according to the present invention is used together with an active ingredient for this purpose.

[0125] Meanwhile, as shown in FIG. 10, the microneedles 15 and through-holes 16 applied to the first region 10 according to the present invention may have a shape in which the through-holes 16 are formed in the shape of a polygon or a closed curve, and at least one microneedle 15 is arranged on the edge of the through-holes 16.

[0126] The advantages of this structure are that in manufacturing a microneedle patch, the microneedles and penetrations are formed simultaneously on a flat surface, and then the microneedles can be bent using a jig or the like to easily provide a patch with a large number of needles formed thereon; and in use, the structure is formed in which the needles are arranged around the wide penetrations, so that the active ingredient supplied from above the penetrations 16 can be easily delivered downward through the penetrations 15, and can also be simultaneously delivered to the inside of the skin along the insertion path of the microneedles.

[0127] That is, in the case of the patch according to the present invention, the active ingredient in the ionic solution carried in the carrier layer is delivered to the inside of the skin through the process described above, and then can be rapidly diffused by receiving an electrical force, so the structure of the microneedle 15 and the penetration part 16 can be applied in a structure further optimized for the present invention.

[0128] Meanwhile, in addition to the beneficial effects described above that are generated by being inserted into the skin and decomposing, the microneedles 15 according to the present invention also play a crucial role in generating a higher electromotive force in accordance with the main purpose of the present invention, thereby enabling iontophoresis of active ingredients to be provided not only as a concept but also as a practical product.

[0129] [Electromotive force experiment with microneedles attached to the skin, with or without them, and with different lengths]

[0130] Figures 11(a) to (c) are photographs of prototypes of a self-current generating skin-applied patch containing a biodegradable metal according to the present invention, with no microneedles, with 100 μm long needles, and with 230 μm long needles, respectively.

[0131] As shown in the photograph, the first electrode layer, whose entire surface comes into contact with the skin, is a 0.07 mm thick magnesium metal thin plate with many hole-shaped perforations formed therein, the second electrode layer, whose partial surface comes into contact with the skin, is a 0.07 mm thick copper metal thin plate, and the ionic solution carrier layer is a 0.28 mm thick pure cotton sheet.

[0132] The first electrode layer and the second electrode layer were electrically insulated and separated by a pure cotton sheet, with no direct electrical connection, and a 0.9% NaCl aqueous solution was used as the electrolyte of the ionic solution.

[0133] In this state, the patches shown in FIG. 11 were applied to the skin of the user, and the operating voltage and operating current were measured. The results are shown in Table 4 below.

[0134] [Table 4]

[0135] That is, compared to (a) without microneedles, it can be confirmed that patches (b) and (c) show a significant increase in electromotive force with an increase in the amount of current, and in particular, in the case of (c) compared to (b), an increase in electromotive force of nearly six times is confirmed. Therefore, it is estimated that if the needle length is 100 μm or more and penetrates the stratum corneum and epidermis of the skin to reach the dermis, a dramatic effect of reducing skin resistance values ​​can be obtained, so it is preferable that the thickness of the microneedles is at least 50 μm, which is the normal epidermal thickness.

[0136] Furthermore, as applied to the patch manufacturing in this experiment, the thinner the thickness of the first or second region, the better the adhesion and adherence to the skin, so it is preferable that the thickness be in an appropriate range. However, particularly in the case of the biodegradable metal of the present invention, it is not easy to process the metal into a thin plate less than 0.07 mm, and if the thickness is 0.7 mm or more, a lifting phenomenon on the skin is observed despite its ductility, so the range of 0.07 to 0.7 mm is preferable.

[0137] Meanwhile, through various experiments, it has been confirmed that the larger the volume of the support layer 30 that supports the ionic solution, i.e., the greater the amount of electrolyte solution, the greater the electrical physical quantity. However, in the case of a patch product having a structure in which the support layer is interposed between the first electrode layer and the second electrode layer according to the above-described embodiment of the present invention, since there is a limit to increasing the thickness of the support layer, it is preferable to maximize its area, and therefore it is preferable to configure the area of ​​the first region 10 corresponding to the area of ​​the support layer 30 to be at least twice as large as that of the second region 20.

[0138] In this regard, a sixth embodiment shown in FIG. 14 will be described as another modification of the third embodiment, which is the basic type.

[0139] Figure 14 is an exploded perspective view showing a structure in which the first region 10 and the second region 20, which are the skin-contacting sides, are arranged at the top of the figure, and the second electrode layer 22, support layer 30, etc. are arranged sequentially at the bottom according to the stacking order.

[0140] That is, the first region 10 and the second region 20 can be made of a biodegradable metal having a magnesium-based composition according to Chemical Formula 1 described below, and the second region 20 is bonded so as to be electrically connected to the material constituting the second electrode layer 22, while the first region is bonded via an insulating layer 60 so as not to be in direct electrical contact with the second electrode layer 22.

[0141] That is, the integrated structure of the insulating layer 60 and the second electrode layer 22 can be manufactured by coating one side of an insulating film (such as a PET film) with a conductive material to form the second electrode layer 22, and then removing the insulating film in a certain area, or by manufacturing the insulating layer 60 by including conductive fibers (such as copper fibers, silver fibers, etc.) and bonding an insulating snow sculpture means to a certain area on one side of a conductive cloth, so that the first area 10 can be laminated and joined onto the insulating layer 60.

[0142] In other words, the structure shown in Figure 14 can be realized by cutting silver cloth woven from silver fibers to the desired shape as the material for the second electrode layer 22, applying an insulating adhesive to a portion of one side of the cloth or attaching insulating tape to form the insulating layer 60 shown in white in Figure 15, and then bonding a biodegradable metal corresponding to the second region 20 to the black portion where the surface of the material of the second electrode layer 22 is exposed, and bonding a biodegradable metal as the first electrode layer 11 corresponding to the first region 10 to the white portion where the second electrode layer 22 is insulated.

[0143] On the other hand, unlike the above-described embodiment in which the support layer 30 is interposed between the first electrode layer 11 and the second electrode layer 22, the embodiment illustrated in FIG. 14 has the support layer 30 located on the outside of the second electrode layer 22 (the lower side in the drawing, opposite the skin-adhering surface), which can result in a structure in which the support layer 30 is located on the outermost surface when attached to the skin for use.

[0144] The advantage of this structure is that, compared to a structure in which a carrier layer 30 made of a pure cotton sheet, natural pulp sheet, rayon sheet, or the like is sandwiched, the first electrode layer 11 and the second electrode layer 22, which are in the form of a thin film, are first laminated and then the carrier layer is bonded to the outside. This makes it easier to manufacture, is advantageous in terms of securing the area of ​​the carrier layer 30, and is also excellent in strength when made into a normal product.

[0145] Furthermore, in a structure such as this in which an ionic solution carrier layer is not disposed between the first electrode layer 11 and the second electrode layer 22, the second electrode layer 22 must also have an opening 65 or the like and be open upward in order to initiate self-current generation when the patch is attached without prior supply of ionic solution. For this reason, it is preferable that the second electrode layer 22 has an opening 65, which allows the ionic solution to be easily and continuously supplied to the first region 10 and the skin underneath, without any limit on the amount of supply.

[0146] At this time, the support layer 30 is further attached in a form that covers at least a portion (preferably the entirety) of the opening 65, so that the ionic solution supplied from above instantly diffuses over the entire surface area of ​​the support layer 30, allowing the electrochemical reaction to occur more smoothly, and the supported ionic solution can be gradually and steadily supplied to the inside of the patch. As a result, ion exchange can occur between the exposed portion of the second electrode layer 22, which was previously electrically insulated, and the first electrode layer 11 using the electrolyte solution of the ionic solution.

[0147] This configuration solves the problems of the limited area of ​​the support layer 30 when the support layer 30 is fixedly interposed between the first electrode layer 11 and the second electrode layer 22 as in the first to fourth embodiments, the problem that moisture leaking from the support layer 30 due to the support layer 30 being located inside the patch can weaken the skin adhesion, and the problem that the ionic solution does not easily spread over the entire surface of the first electrode layer 11, and can be expected to provide additional advantages such as acting as a filter that can filter out foreign substances mixed in the ionic solution.

[0148] The sixth embodiment of the patch is actually produced and attached to the skin as shown in the photograph in Figure 15. This configuration confirms that the self-current generating skin-applied patch containing a biodegradable metal according to the present invention can be produced in a structure that can smoothly and continuously supply an ionic solution containing an active ingredient through the topmost support layer 30 even when attached to the skin.

[0149] Characterization of patches containing Ag / AgCl mixed electrode materials.

[0150] Following the electromotive force experiments using magnesium metal as the first electrode layer and either Cu or SUS301 as the second electrode layer, we also conducted a characteristic evaluation of a patch structure, which is easily realized using a structure like that of Embodiment 6. Two electrode layers were prepared: a 0.07 mm-thick magnesium metal thin plate containing unavoidable impurities as the first electrode layer, a 0.05 mm-thick PET film coated with a paste-like Ag / AgCl mixture as the second electrode layer, and a 0.03 mm-thick Cu thin plate as a comparison sample. Three samples were prepared in which the first and second electrode layers were laminated and bonded while being insulated from each other. The configurations of the samples are shown in Figure 16, and from left to right, they were confirmed to have the properties shown in Table 5 below.

[0151] [Table 5]

[0152] The paste-like Ag / AgCl mixture used in the experiment was SC141 product sold by KT Corporation, which was heated to 120°C for 30 minutes to harden. The Ag / AgCl mixture was coated onto a 50μm PET film at different thicknesses as follows: The results of the experiment on the above samples under a load resistance of 500Ω are summarized in Table 6 below. The applied electrolyte solution was a 0.9% NaCl aqueous solution.

[0153] [Table 6]

[0154] Compared to Sample 1, which was an experimental result using a thin Cu plate, the Ag / AgCl showed a clear increase in results. The results of Samples 2 and 3 confirmed that the thicker the Ag / AgCl coating layer, the greater the increase in operating voltage, operating current, and electromotive force. However, when a second electrode layer + insulating layer structure is realized in the form of a coating layer on a film, it was confirmed that there is an appropriate thickness in terms of crushing and flexibility. In conclusion, it was confirmed that using Ag as the second electrode layer material compared to Cu offers electrical advantages. Furthermore, it was confirmed that using silver cloth woven with silver fibers as the second electrode layer, rather than a coating method, can produce a product with advantages in terms of patch flexibility and adhesion.

[0155] While specific embodiments of the present invention have been described above, it is needless to say that various modifications can be made without departing from the scope of the present invention.

[0156] Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined by the following claims as well as equivalents to these claims.

Claims

1. The device comprises a first region (10) that contacts the user's skin, and a second region (20) that is spaced apart from the first region (10) and contacts the adjacent skin that the first region (10) contacts, the first region (10) or the second region (20) includes a biodegradable metal that can be decomposed and absorbed by contacting the user's skin or reacting with water in the tissue; a first electrode layer (11) in the form of a thin sheet that directly contacts the user's skin and is provided integrally with the first region (10), and has at least one through-hole that allows fluid delivery from the side opposite to the skin contact; a second electrode layer (22) made of a substance different from the substance constituting the first electrode layer (11) in standard reduction potential, located on the opposite side of the first electrode layer (11) to the side that contacts the skin while being insulated from the first electrode layer (11), and at least a portion of the second electrode layer (22) extending therefrom and electrically connected to the second region (20); a support layer (30) in the form of a sheet having a thickness, located on the opposite side of the first electrode layer (11) that comes into contact with the skin, and made of a hydrophilic material that can support an ionic solution. A self-current generating skin application patch containing a biodegradable metal.

2. The self-current generating skin application patch containing a biodegradable metal as described in claim 1, characterized in that the first area (10) or the second area (20) includes at least one microneedle (15) protruding in the direction of contact with the user's skin.

3. The biodegradable metal is represented by the following chemical formula 1: [Chemical formula 1] Mg ａ Zn ｂ Ca ｃ X ｄ (wherein a, b, c, and d are the weight percentages of each component, a+b+c+d=100 weight%, a is the largest, 0≦b≦5, 0≦c≦1, 0≦d≦1, and X is one or more types of impurities that are elements other than Mg, Zn, and Ca.) is expressed as A self-current generating patch for application to the skin, comprising the biodegradable metal according to claim 1 or 2.

4. The first region (10) and the first electrode layer (11) are biodegradable metals according to Chemical Formula 1, and the second electrode layer (22) contains a different substance having a higher standard reduction potential than the first electrode layer (11). A self-current generating patch for application to the skin, comprising the biodegradable metal according to claim 3.

5. The second electrode layer (22) is composed of one or more materials selected from copper, zinc, silver, silver chloride, iron, and stainless steel. A self-current generating patch for application to the skin, comprising the biodegradable metal according to claim 4.

6. The second region (20) is a biodegradable metal according to Chemical Formula 1 and is electrically connected to the portion extending from the second electrode layer (22). A self-current generating patch for application to the skin, comprising the biodegradable metal according to claim 5.

7. The second electrode layer (22) is a biodegradable metal according to Chemical Formula 1, and the first electrode layer (11) contains a different substance having a higher standard reduction potential than the second electrode layer (22). A self-current generating patch for application to the skin, comprising the biodegradable metal according to claim 3.

8. The microneedle (15) has a length of 0.02 mm or more. A self-current generating patch for application to the skin, comprising the biodegradable metal according to claim 2.

9. The support layer (30) is positioned in a laminated form between the first electrode layer (11) and the second electrode layer (22). A self-current generating patch for application to the skin, comprising the biodegradable metal according to claim 1.

10. The first electrode layer (11) and the second electrode layer (22) are stacked in a state insulated from each other by an insulating layer (60), The second electrode layer (22) has an opening (65) that exposes at least a part of the through portion of the first electrode layer (11), The carrier layer (30) is positioned in a manner to cover at least a portion of the opening (65) on the side of the first electrode layer (11) opposite to the skin contact side. A self-current generating patch for application to the skin, comprising the biodegradable metal according to claim 1.

11. The through-hole formed in the first electrode layer (11) is hole-shaped, and at least one of the microneedles (15) is bent along the edge of the hole toward the user's skin. A self-current generating patch for application to the skin, comprising the biodegradable metal according to claim 2.

12. The second electrode layer (22) is applied in the form of a flexible fabric made with conductive fibers. A self-current generating patch for application to the skin, comprising the biodegradable metal according to claim 4.

13. The ionic solution includes at least one selected from the group consisting of phosphate buffered saline and an aqueous sodium chloride solution. A self-current generating patch for application to the skin, comprising the biodegradable metal according to claim 1.

14. The ionic solution further contains at least one of functional cosmetics and pharmaceutical active ingredients. A self-current generating patch for application to the skin, comprising the biodegradable metal according to claim 1 or 13.

15. The active ingredient is ionic A self-current generating skin application patch comprising the biodegradable metal according to claim 14.

16. The support layer (30) is made of one or more dry fabric materials selected from the group consisting of a pure cotton sheet, a natural pulp sheet, and a rayon sheet. A self-current generating patch for application to the skin, comprising the biodegradable metal according to claim 1.

17. The device further includes a capsule (40) that ejects the ionic solution onto the carrier layer (30) upon user-initiated action. A self-current generating patch for application to the skin, comprising the biodegradable metal according to claim 1 or 16.

18. The area of ​​the first region (10) is at least twice the area of ​​the second region (20). A self-current generating patch for application to the skin, comprising the biodegradable metal according to claim 9.

19. The first region (10) formed integrally with the first electrode layer (11) is in the form of a thin sheet and has a thickness of 0.07 to 0.7 mm. A self-current generating patch for application to the skin, comprising the biodegradable metal according to claim 1.

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