JP4833015B2 - Electrode structure for iontophoresis having liquid crystal switching separator and iontophoresis device using the same - Google Patents

Description

  The present invention relates to a technique (transdermal drug delivery) for transdermally administering various ionic drugs by iontophoresis, and in particular, an electrode structure used for iontophoresis and an iontophoresis using the same. The present invention relates to a lasis device.

  An ionic drug placed on the surface of the skin or mucous membrane (hereinafter simply referred to as “skin”) of a predetermined part of the living body is given an electromotive force to drive the ionic drug to the skin, and the drug is passed through the skin. The method of introducing (penetrating) into the body is called iontophoresis (iontophoresis, iontophoresis, iontophoresis) (see Patent Document 1, etc.).

  For example, positively charged ions are driven (transported) into the skin on the anode side of the electrical system of the iontophoresis device. On the other hand, ions having a negative charge are driven (transported) into the skin on the cathode side of the electrical system of the iontophoresis device.

  Many proposals have been made for the iontophoresis device as described above. (For example, refer to Patent Documents 1 to 7). Among these, as an electrode structure for iontophoresis, an electrode, an electrolyte solution holding unit, an ion exchange membrane that selects ions having a polarity opposite to that of the ionic drug, a chemical solution holding unit that impregnates and holds the ionic drug, and There is a proposal of an electrode structure in which an ion exchange membrane that selects ions having the same polarity as an ionic drug is laminated.

  However, in this electrode structure, the components in the electrolytic solution and the components in the chemical solution (mainly through the ion-exchange membrane that selects the ions having the opposite polarity to the ionic drug) are manufactured and used until the use. Ionic components of the opposite polarity to the ionic drug) may move, and depending on the components in the electrolyte solution or the components in the chemical solution, adverse effects (for example, alteration of the drug component, decreased drug stability, drug release) There are cases in which a possible amount is reduced or a transport number is reduced due to mixing of different ions.

Therefore, until the use of the electrode structure for iontophoresis, it is an important issue to prevent the mass transfer between the electrolytic solution and the chemical solution and to allow a certain mass transfer during the use.
JP 63-35266 JP-A-4-297277 JP 2000-229128 A JP 2000-229129 A JP 2000-237327 A JP 2000-237328 A International Publication WO03 / 037425A1 JP 62-261951 A JP 2003-149193 A

  The present invention has been made in view of the above-mentioned problems of the prior art, and prevents the mass transfer between the electrolytic solution and the chemical solution until the iontophoresis electrode structure is used. An object of the present invention is to provide an iontophoresis electrode structure provided with a separator capable of moving a certain substance, and an iontophoresis device using the same.

  In order to solve the above problems, an electrode structure for iontophoresis holding an ionic drug according to the present invention includes an electrode connected to a power supply device having the same polarity as the ionic drug in the electrode structure. An electrolyte solution holding unit that impregnates and holds an electrolyte solution disposed adjacent to the electrode; and an ion exchange membrane that selects ions having a polarity opposite to that of the ionic drug disposed adjacent to the electrolyte solution holding unit And a chemical solution holding part that impregnates and holds the ionic drug arranged adjacent to the ion exchange membrane, and ions having the same polarity as the ionic drug arranged adjacent to the chemical solution holding part An ion exchange membrane, and at least adjacent to at least one surface of the ion exchange membrane that selects ions having a polarity opposite to that of the ionic drug, the permeation of the substance and the blocking of the substance are switched by changing the orientation of the liquid crystal. That is characterized in that the liquid crystal switching separator is disposed.

  In a preferred embodiment of the present invention, the separator blocks mass transfer during the production and storage of the electrode structure, but the liquid crystal orientation is changed by voltage application or temperature change so as to allow permeation of the material. It will be.

  In another preferred embodiment of the present invention, the separator changes the orientation of the liquid crystal when a voltage of 6 V or higher is applied, thereby allowing the transmission of the substance.

  In another preferred embodiment of the present invention, the separator changes the alignment of the liquid crystal by heating at 30 ° C. or higher to allow the permeation of the substance.

  The iontophoresis device according to the present invention is a drug administration comprising a power supply device and two or more electrode structures including at least one electrode structure connected to the power supply device and holding the ionic drug. Means and current control means for controlling the current flowing to the electrode structure, and according to the current flowing from the current control means, the ionic drug is released from the electrode structure and transcutaneously into the living body. It is characterized by the fact that it is administered in a controlled manner.

  Another electrode structure for iontophoresis holding an ionic drug according to the present invention is an electrode structure for iontophoresis holding an ionic drug, which is the same kind as the ionic drug in the electrode structure. An electrode connected to a power supply device of the polarity, an electrolyte solution holding part impregnating and holding an electrolyte solution arranged adjacent to the electrode, and the ionic drug arranged adjacent to the electrolyte solution holding unit An ion exchange membrane that selects ions of opposite polarity, a chemical solution holding portion that is impregnated and held with the ionic drug arranged adjacent to the ion exchange membrane, and a chemical solution holding portion that is arranged adjacent to the chemical solution holding portion, An ion exchange membrane that selects ions having the same polarity as the ionic drug, and adjacent to at least one surface of the ion exchange membrane that selects ions having the same polarity as the ionic drug, by changing the orientation of the liquid crystal. Capable of switching the blocking of the over-the material, in which the liquid crystal switching separator characterized by comprising disposed.

  As described above, in the electrode structure for iontophoresis according to the present invention, the permeation of the substance and the substance are caused by the change in the orientation of the liquid crystal adjacent to at least one surface of the ion exchange membrane that selects ions having the opposite polarity to the ionic drug. Since the liquid crystal switching separator that can switch the blocking of the liquid crystal is arranged, the mass transfer between the electrolyte and the chemical solution is prevented until the electrode structure for iontophoresis is used. It can be moved.

Hereinafter, the present invention will be described based on preferred specific examples illustrated in the drawings.
The embodiment shown in FIG. 1 is a schematic view of the use state of the iontophoresis electrode structure A1 arranged on the skin S according to a preferred embodiment of the present invention. This electrode structure A1 is used as a working electrode structure for transdermally administering an ionic drug in an iontophoresis device. The electrode structure A1 for iontophoresis impregnates and holds an electrode 11 connected via a wire to a power supply device having the same polarity as the charge of the ionic drug, and an electrolyte solution disposed adjacent to the electrode 11. Electrolytic solution holding unit 12, liquid crystal switching separator F1 disposed adjacent to electrolytic solution holding unit 12, and ion exchange membrane 13 for selecting ions having the opposite polarity to the ionic drug disposed adjacent to separator F1 And a chemical solution holding unit 14 that is disposed adjacent to the ion exchange membrane 13 and impregnating and holding the ionic drug, and ions having the same polarity as the ionic drug that are disposed adjacent to the chemical solution holding unit 14 are selected. An ion exchange membrane 15 is provided, and the whole is accommodated by a cover 16.

  2 shows an iontophoresis electrode structure (working-side electrode structure) A1, a power supply device C, and a non-working side as a counter electrode of the iontophoresis electrode structure A1 according to a preferred embodiment of the present invention. 1 is a schematic diagram showing a state where an iontophoresis device X1 including an electrode structure B1 is disposed on a skin S. FIG.

  The electrode structure A1 for iontophoresis is connected to the same kind of polar side as that of the ionic drug in the power supply device C through an electric wire. In addition, the non-working side electrode structure B1 impregnates and holds the electrode 21 connected to the polarity side opposite to the ionic drug in the power supply device C through an electric wire and the electrolyte solution disposed adjacent to the electrode 21. An electrolyte solution holding unit 22, an ion exchange membrane 23 that selects ions having the same polarity as the ionic drug arranged adjacent to the electrolyte solution holding unit 22, and an electrolyte solution arranged adjacent to the ion exchange membrane 23 An electrolyte solution holding part 24 for impregnating and holding, and an ion exchange membrane 25 for selecting ions having a polarity opposite to that of the ionic drug arranged adjacent to the electrolyte solution holding part 24, are entirely accommodated in the cover 16. ing. In addition, the said non-working side electrode structure B1 is illustrated as one preferable aspect, and is not limited to the said aspect. In FIG. 2, the iontophoresis electrode structure A1 is connected to the + side of the power supply device C, and the non-working side electrode structure B1 is connected to the − side of the power supply device C. Depending on the situation, this can naturally be reversed.

In the iontophoresis device X1, when the electrode structure A1 holding the ionic drug is energized by the power supply device C, the ionic drug moves to the opposite side of the electrode by electrophoresis by an electric field (electric field). Then, it is transdermally administered to the living body through the ion exchange membrane 15. At this time, since the ion exchange membrane 13 arranged on the electrode side selects ions having the opposite polarity to the ionic drug, the ion exchange membrane 13 prevents movement of the ionic drug to the electrode side, while the ions arranged on the skin. Since the exchange membrane 15 selects ions having the same polarity as the ionic drug, the ionic drug can be efficiently released and administered to the skin S with high transport efficiency. Furthermore, the electrode structure in the present invention has the above-described configuration, thereby preventing skin damage based on an electrochemical reaction and enabling safe administration of an ionic drug. Moreover, as preferable energization conditions in the iontophoresis device, for example, the following conditions are adopted. Constant current conditions, specifically 0.1~0.5mA / cm ^2, preferably 0.1~0.3mA / ^cm 2. The above-mentioned constant current is realized and safe voltage conditions, specifically 50V or less, preferably 30V or less.

  In the present invention, both the working electrode structure and the non-working electrode structure can be configured to include a plurality of electrode structures. In that case, a plurality of types of ionic drugs may be held in one working electrode structure. Further, when a plurality of ionic drugs having different polarities are administered, a working electrode structure and a non-working electrode structure are provided on the anode side, and a working electrode structure and a non-working electrode structure are also provided on the cathode side. A body can also be provided.

  Also, a plurality of electrode structures may be configured as a drug administration means and assembled in one package for convenience of handling. The material used for the package in this case is not particularly limited as long as it does not affect the administration of the ionic drug, and examples thereof include polyolefin for medical devices. Further, a current control means may be provided to reliably administer a predetermined amount of drug at a predetermined time. For example, the drug administration means, current control means and power supply device may be a button battery, and the current control means may be By configuring as an integrated circuit and reducing the size, the drug administration means, the current control means, and the power supply device may be configured integrally.

  The separator used for the electrode structure is a liquid crystal switching separator that can switch between permeation and blocking of the substance by changing the orientation of the liquid crystal, and is an ion-exchange membrane that selects ions having the opposite polarity to the ionic drug. It is provided adjacent to at least one side. In FIG. 1, the separator F <b> 1 is provided adjacent to the electrolyte solution holding unit 12 side of the ion exchange membrane 13, but may be provided on the chemical solution holding unit 14 side or both sides.

  In another aspect of the present invention, a liquid crystal switching separator may be provided adjacent to at least one surface of an ion exchange membrane that selects ions having the same polarity as the ionic drug. By doing so, the administration of the drug itself can be controlled by the separator, allowing the drug to pass only when necessary, and more efficient drug administration can be realized more reliably.

  This separator is preferably formed of a liquid crystal substance and a resin matrix, and blocks the movement of the substance during the production and storage of the electrode structure. It is acceptable. The substance that is allowed to permeate only needs to contain at least ions that are expected to pass through the ion exchange membrane, and may allow other substances to pass therethrough. By providing such a separator, it is possible to prevent the movement of the substance between the electrolytic solution and the chemical solution until the use of the electrode structure for iontophoresis and to allow the movement of the substance at the time of use. In addition, it is possible to prevent adverse effects caused by movement of components in the electrolyte solution and components in the chemical solution (mainly ionic components having a polarity opposite to that of the ionic drug) through the ion exchange membrane before use after production. .

  Examples of the constant stimulus for changing the alignment of the liquid crystal include electrical stimulation and heat (temperature). For example, the material permeation is blocked when no voltage is applied, but if a resin that allows the material permeation by changing the orientation by applying a voltage of 6 V or more is used, the material permeation is blocked while the electrode structure is stored. However, when a voltage is applied to start drug administration by iontophoresis, the separator can be made to permeate the substance. Also, for example, if the temperature is lower than 30 ° C., the permeation of the substance is blocked, but if a resin that allows the permeation of the substance due to a change in liquid crystal alignment by heating at 30 ° C. or higher is used, the electrode structure is stored in a cold place. Although the substance permeation is blocked, when the electrode structure is attached to a living body, a separator that allows the substance to permeate by heating with body temperature can be obtained.

  The change in liquid crystal alignment due to a certain stimulus may be reversible or irreversible. When a liquid crystal material that has irreversible orientation changes is used, as long as the constituents of the electrode structure, such as drugs, can withstand that constant stimulus, by applying a strong stimulus that cannot be applied to a living body, Material permeation becomes acceptable. For example, a voltage of 100 V is applied once immediately before use to allow the substance permeation of the separator, or it is heated to 40 ° C. once before use to permit the substance permeation of the separator, and then attached to a living body to be ionized. Drug administration can be initiated by tophoresis. When a liquid crystal material that reversibly changes its orientation is used, it is possible to allow the separator to permeate the substance only during administration when intermittent drug administration is performed.

  The liquid crystal that can be used for the separator in the present invention is not particularly limited as long as it is a liquid crystal substance whose orientation changes so that a certain substance can be transmitted under a predetermined condition. For example, as a separator material using liquid crystal, Polymer composite membranes as described in JP-A-62-261951, that is, polycarbonate (PC), N- (4-ethoxybenzylidene) -4-butylaniline (EBBA), and crown (thio) ether ( For example 4 '-(N-butyryl) -4'-(N-1 "H, 1" H, 2 "H, 2" H, 3 "H, 3" H-perfluoroundecyl) -aminobenzo-15- Crown-5 etc.).

  Examples of the shape of the separator include those having a thickness of 1 μm to 1 mm.

  As the electrode used for the electrode structure, for example, an inert electrode made of a conductive material such as carbon or platinum can be preferably used.

  The electrolyte solution holding part used in the electrode structure can be constituted by a thin film body having a characteristic of impregnating and holding the electrolyte solution. In addition, this thin film body can use the same kind as the material used for the chemical | medical solution holding | maintenance part for impregnating and hold | maintaining the ionic drug mentioned later. As the electrolytic solution, a desired one can be used as appropriate depending on the conditions of the applied drug and the like, but those that damage the skin of the living body due to electrode reactions should be avoided. As an electrolytic solution suitable for the present invention, an organic acid or salt thereof present in a metabolic circuit of a living body is preferable from the viewpoint of harmlessness. For example, lactic acid, fumaric acid, and the like are preferable. Specifically, an aqueous solution of 1M lactic acid and 1M sodium fumarate in a 1: 1 ratio is preferable. Such an electrolytic solution is preferable because it has a high solubility in water and conducts current well, and when a current is passed at a constant current, the electrical resistance is low and the pH change in the power supply device is relatively small.

  In general, the electrolyte solution is preferably one that does not interact with the drug. However, in the present invention, the electrolyte solution interacts with drugs such as alteration of drug components, decrease in drug stability, decrease in drug releasable amount, and decrease in transport number due to mixing of different ions into the drug solution. Even if it produces an action, it is excellent in that it can be suitably used.

  The chemical solution holding unit is configured by a thin film body that is impregnated and held with an ionic drug. Such a thin film body has sufficient ability to impregnate and hold an ionic drug, and has the ability to transfer the ionic drug impregnated and held under a predetermined electric field condition to the skin side (ion transferability, ionic conductivity). It is important that the property is sufficient. Materials that have both good impregnation retention properties and good ion transport properties include acrylic resin hydrogel bodies (acrylic hydrogel membranes), segmented polyurethane gel membranes, or ionic conductivity for forming gelled solid electrolytes. (For example, an acrylonitrile disclosed in JP-A No. 11-273452, wherein acrylonitrile is 50 mol% or more, preferably 70 to 98 mol% or more, and the porosity is 20 to 80%. And a porous polymer based on a nitrile copolymer). Moreover, when impregnating the above chemical | medical solution holding | maintenance part, the impregnation rate (100 * (WD) / D [%] when the weight at the time of drying is set to D and the weight after an impregnation is set to W) is preferable. Is 30-40%.

  As the ion exchange membrane used in the electrode structure, it is preferable to use a cation exchange membrane and an anion exchange membrane in combination. Preferred examples of the cation exchange membrane include Neocepta (NEOSEPTA, CM-1, CM-2, CMX, CMS, CMB, CLE04-2) manufactured by Tokuyama Corporation. Moreover, as an anion exchange membrane, Preferably, Tokuyama Co., Ltd. neoceptor (NEOSEPTTA, AM-1, AM-3, AMX, AHA, ACH, ACS, ALE04-2, AIP-21) etc. are mentioned. Other preferred examples include an ion exchange membrane in which a part or all of the voids of the porous film are filled with an ion exchange resin having a cation exchange function, or an ion exchange resin having an anion exchange function. A filled ion exchange membrane can be mentioned.

  Here, as the ion exchange resin, a fluorine-based resin in which an ion-exchange group is introduced into a perfluorocarbon skeleton or a hydrocarbon-based resin having a non-fluorinated resin as a skeleton can be used. Hydrocarbon ion exchange resins are preferably used because of their simplicity. The filling rate of the ion exchange resin into the porous film varies depending on the porosity of the porous film, but can be, for example, 5 to 95% by mass, preferably 10 to 90% by mass, and more preferably. Is 20-60 mass%.

  In addition, the ion exchange group of the ion exchange resin is not particularly limited as long as it is a functional group that generates a group having a negative or positive charge in an aqueous solution. Such functional groups may be present in free acid or salt form. Examples of the cation exchange group include a sulfonic acid group, a carboxylic acid group, and a phosphonic acid group, and a sulfonic acid group is preferable. Moreover, as a counter cation of a cation exchange group, alkali cations, such as sodium ion and potassium ion, ammonium ion, etc. are mentioned, for example. Examples of the anion exchange group include a primary to tertiary amino group, a quaternary amino group, a pyridyl group, an imidazole group, a quaternary pyridium group, and a quaternary imidazolium group, and preferably a quaternary ammonium group. Or it is a quaternary pyridium group. Examples of the counter cation of the anion exchange group include halogen ions such as chlorine ions and hydroxy ions.

  In addition, as the porous film, a film having a large number of pores communicating with the front and back, or a sheet-like one is used without particular limitation. In order to achieve both high strength and flexibility, a thermoplastic resin is used. It is preferable that it consists of. Examples of the thermoplastic resin constituting the porous film include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 4-methyl-1-pentene, and 5-methyl-1- Polyolefin resins such as α-olefin homopolymer or copolymer such as heptene; polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-olefin copolymer, etc. Vinyl chloride resin: polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-ethylene copolymer Fluorine resin such as nylon 66 Polyamide resin, and the like, but considering the mechanical strength, flexibility, chemical stability, chemical resistance, etc., it is preferably a polyolefin resin, more preferably polyethylene or polypropylene, Polyethylene is preferable.

  Furthermore, the average pore diameter of the porous film made of the thermoplastic resin is preferably 0.005 to 5.0 μm, more preferably 0.01 to 2.0 μm, and still more preferably 0.02 to 0.00. 2 μm. In addition, the said average aperture means the average flow hole diameter measured based on the valve point method (JISK3832-1990).

  Moreover, the porosity of a porous film becomes like this. Preferably it is 20 to 95%, More preferably, it is 30 to 90%, More preferably, it is 30 to 60%. Further, the thickness of the porous film is preferably 5 to 140 μm, more preferably 10 to 130 μm, still more preferably 15 to 55 μm, considering the thickness of the ion exchange membrane finally formed. . The thickness of the anion exchange membrane or cation exchange membrane formed by such a porous film is usually the thickness of the porous film + 0 to 20 μm.

  As described above, the iontophoresis electrode structure according to the present invention is characterized by holding an ionic drug.

  Specific examples of the drug include the following.

  Examples of ionic drugs include local anesthetics (procaine hydrochloride, lidocaine hydrochloride, etc.), therapeutic agents for gastrointestinal diseases (carnitine chloride, etc.), skeletal muscle relaxants (bancronium bromide, etc.), antibiotics (tetracycline series preparations, kanamycin series) Preparations, gentamicin preparations) and the like.

  Examples of ionic drugs that can be negatively ionized include vitamins (riboflavin phosphate, nicotinic acid, ascorbic acid, folic acid, etc.), corticosteroids (hydrocortisone-based water-soluble preparations, prednisolone sodium phosphate, dexamethasone sodium phosphate, etc.) Dexamethasone and prednisolone water-soluble preparations), antibacterial drugs (quinolone preparations) and the like.

  Examples of the vaccine include BCG vaccine, hepatitis A vaccine, melanoma vaccine, measles vaccine, polio vaccine, influenza vaccine and the like.

  Examples of the adjuvant include MPL (Monophosphoryl lipid A), DMPC (dimyristoylphosphatidylcholine), QS-21, DDA (Dimethyldioctadecyl ammonium chloride), RC-529, and the like.

  Furthermore, preferable combinations of vaccine and adjuvant include, for example, positively ionized vaccine and RC-529, negatively ionized vaccine and DDA, BCG vaccine and MPL, hepatitis A vaccine and DMPC, melanoma vaccine and QS- 21 etc. are mentioned.

  In addition to the above combination of vaccine and adjuvant, preferred drug combinations include, for example, a combination of antihypertensive and antihypertensive diuretic, such as lisinopril and hydrochlorothiazide, methyldopa and hydrochlorothiazide, clonidine hydrochloride and chlorthalidone, and benazepril and hydrochlorothiazide hydrochloride. Insulin and metformin hydrochloride are included as a combination of antidiabetics, and other combinations include ozagrel hydrochloride and ozagrel sodium, codeine hydrochloride and promethazine hydrochloride, and the like.

  In addition, the ionic drugs held in the iontophoresis electrode structure according to the present invention may be appropriately combined in a plurality of types depending on the type of disease, the condition of the patient, and the like. Although this can hold | maintain a different ionic drug for every electrode structure, you may combine multiple types in a single electrode structure.

  The amount of the ionic drug is determined for each ionic drug so that an effective blood concentration preset when applied to the patient can be obtained for an effective time. It is set by those skilled in the art according to the area of the drug release surface, the voltage in the electrode device, the administration time, and the like.

  Details of each constituent material as described above are described in Patent Document 7 related to the present applicant, and the present invention includes the contents described in this document.

The figure which shows the outline | summary of the electrode structure for iontophoresis by this invention. The figure which shows the outline | summary of the iontophoresis apparatus provided with the electrode structure for iontophoresis by this invention.

Explanation of symbols

X1 iontophoresis device A1 working electrode structure B1 non-working electrode structure 11, 21 electrodes 12, 22, 24 Electrolyte holding part F1 separators 13, 15, 23, 25 ion exchange membrane 14 chemical holding part 16, 26 Cover S Skin

Claims (6)

An iontophoresis electrode structure for holding an ionic drug,
An electrode connected to a power supply of the same polarity as the ionic drug in the electrode structure;
An electrolytic solution holding part for impregnating and holding an electrolytic solution disposed adjacent to the electrode;
An ion exchange membrane that selects ions having a polarity opposite to that of the ionic drug disposed adjacent to the electrolyte solution holding unit;
A chemical solution holding unit impregnated and holding the ionic drug disposed adjacent to the ion exchange membrane; and an ion exchange method that selects ions having the same polarity as the ionic drug arranged adjacent to the chemical solution holding unit A membrane, and at least
A liquid crystal switching separator is disposed adjacent to at least one surface of an ion exchange membrane that selects ions having a polarity opposite to that of the ionic drug, and capable of switching between permeation of the substance and blocking of the substance by changing the orientation of the liquid crystal. An electrode structure for iontophoresis characterized by the above.   The separator separates mass transfer during manufacture and storage of the electrode structure, but changes the orientation of the liquid crystal according to voltage application or temperature change to allow permeation of the material. An electrode structure for iontophoresis according to 1.   The electrode structure for iontophoresis according to claim 2, wherein the separator changes the orientation of the liquid crystal when a voltage of 6 V or more is applied, thereby allowing permeation of the substance.   The electrode structure for iontophoresis according to claim 2, wherein the separator changes the alignment of the liquid crystal by heating at 30 ° C. or higher and allows the permeation of the substance. A power supply device, a drug administration means including two or more electrode structures connected to the power supply device and including one or more electrode structures according to claim 1, and a current flowing to the electrode structure is controlled. Current control means for
An iontophoresis device, wherein an ionic drug is released from the electrode structure and transcutaneously administered to a living body according to a current flowing from the current control means. An iontophoresis electrode structure for holding an ionic drug,
An electrode connected to a power supply of the same polarity as the ionic drug in the electrode structure;
An electrolytic solution holding part for impregnating and holding an electrolytic solution disposed adjacent to the electrode;
An ion exchange membrane that selects ions having a polarity opposite to that of the ionic drug disposed adjacent to the electrolyte solution holding unit;
A chemical solution holding unit impregnated and holding the ionic drug disposed adjacent to the ion exchange membrane; and an ion exchange method that selects ions having the same polarity as the ionic drug arranged adjacent to the chemical solution holding unit A membrane, and at least
Adjacent to at least one surface of an ion exchange membrane that selects ions having the same polarity as the ionic drug, a liquid crystal switching separator that can switch between permeation of the substance and blocking of the substance by changing the orientation of the liquid crystal is disposed An electrode structure for iontophoresis characterized by the following.

Images