JP2003169853A - Iontophoresis element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an iontophoresis element in which a structure is simplified, production process can be made simple and product costs can be reduced. <P>SOLUTION: In the iontophoresis element provided with an anode part composed of a conductive metal, a cathode part composed of a semiconductor, a protecting resistor having a current limiting function for electrically connecting the anode part and the cathode part, and a pad member impregnated with an ionic chemical while contacting the pad member with any one electrode part of the anode part and the cathode part, and locating the pad member so that the other electrode part and the pad member can be simultaneously contacted to the skin in the case of use, one electrode part is a pedestal, the pedestal has a holding groove and a holding hole, the holding groove is formed around the holding hole, the protecting resistor is stick-shaped and longitudinally held in the holding hole, and the pad member is held by the holding groove. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an iontophoresis device utilizing the action of iontophoresis.

[0002]

2. Description of the Related Art The transdermal administration method is an excellent administration method as a means for delivering a drug having a constant concentration to a predetermined position of a living body. In addition, the transdermal administration method is superior in topical administration to intravenous injection and oral administration, and since it penetrates from the skin directly above the affected area to the inside, the first-pass detoxification effect on the liver can be avoided. Therefore, there is a feature that side effects and doses of drugs are not required. Examples of its practical application include treatment of chronic diseases of the musculoskeletal system and connective tissue, prevention of angina pectoris, bronchitis calming, and treatment of neurological diseases.

[0003] Usually, transdermal administration is carried out by applying a material containing an active ingredient to a plaster to skin-contact a predetermined site, and using concentration diffusion to penetrate a subcutaneous tissue from the skin-contact site to a certain concentration of the drug. . However, effective penetrants for the treatment of diseases are generally high-molecular compounds and have a complicated three-dimensional structure. Therefore, relying solely on the simple concentration diffusion phenomenon will prevent the drug at the required concentration from reaching the affected area. In many cases, a sufficient therapeutic effect cannot be obtained. Therefore, in recent years, iontophoresis has attracted attention as a means for increasing the effective penetration rate by the transdermal administration method.

In iontophoresis, the active ingredient of a drug to be permeated is ionized, and the drug is smeared under one of the electrodes (active electrode) installed at two places with the skin as a current-carrying path, while the other electrode The active ingredient ions are forcibly migrated into the skin current-carrying path by the electric repulsive force of the electricity supplied from the external power source.

The external power source in iontophoresis is
Due to the high resistance of the skin current-carrying path, a fixed type 100 V class DC power source is often used in hospitals under the supervision of a doctor.
However, since a patient cannot use this in daily life, a battery is generally used. However, since the electromotive force of the battery rapidly decreases with the time of use, there is a problem that the effect of drug penetration by electrophoresis decreases.

On the other hand, in order to solve such a problem,
Two kinds of metals with different ionization tendency are conductively connected, an electromotive force is generated by using an electric closed circuit formed at the time of skin contact, and an ionic drug using a metal salt of the same kind as the anode metal is used for the anode. Iontophoresis applied to the skin-contacting surface has been proposed. (Unexamined-Japanese-Patent No. 60-20320) This method is an attempt of utilizing the redox reaction between electrodes unlike the above-mentioned prior art. However, this method has major drawbacks. In other words, when an electric closed circuit is formed by skin contact, first, electrons flow from the cathode having a large ionization tendency to the anode, and the cathode from which electrons have escaped is chemically activated. Negative ions derived from water distributed on or near the skin-contact surface of the cathode enter the surface layer of the cathode and are adsorbed to form a hydroxide on the skin-contact surface of the cathode. Since this hydroxide is an insulator, the electromotive force is rapidly reduced, and the iontophoresis stops soon.

In order to solve this drawback, a skin contact power generation type iontophoresis element has been proposed which uses a semiconductor for the cathode and is combined with a metal anode. (Flat 03-
16573) A front view is shown in FIG. 7 and a cross-sectional view taken along line ZZ is shown in FIG. 8. In this device, a pad 14 impregnated with a negative ionic drug is arranged on the lower surface of the metal anode 11,
Conductor 1 for metal anode 11 and semiconductor cathode 12 in a non-skin contact area
It is directly connected by 5. In use, when the metal anode 11 is skin-contacted with the pad 14 disposed therebelow, the metal anode 11 and the semiconductor cathode 12 form an electrically closed circuit. When the electrons flow out from the semiconductor cathode 12 to the metal anode 11, the holes generated in the semiconductor cathode are forced out to the skin contact surface by the internal electric field of the Schottky barrier formed in the skin contact surface. Since it flows out to the skin as semiconductor ions, the electrical neutrality of the semiconductor cathode is maintained and stable long-term power generation becomes possible.

[0008]

However, in the structure of the element for iontophoresis as described above, there is a possibility that the current increases and the skin is damaged as the activation of the skin progresses after the skin contact. In addition, it is actually very difficult to manufacture an iontophoresis device in which conductors are arranged, and it is not suitable for mass production. Therefore, there is a point to be improved in manufacturing, use, and cost.

The present invention has been made under such circumstances, and an object of the present invention is to provide an iontophoresis element which has a simple structure and can simplify the manufacturing process and reduce the product cost. It is in.

[0010]

In order to achieve the above-mentioned object, an iontophoresis device of the present invention comprises an anode part made of a conductive metal, a cathode part made of a semiconductor, and an anode part and a cathode part. A protective resistor electrically connected to and having a current limiting function, and a contact member impregnated with an ionic drug, the contact member contacting either one of the anode part or the cathode part. Then, when used, the other electrode portion and the contact member are arranged to be in skin contact at the same time. When one electrode portion is an anode, the other electrode portion here is a cathode, and when one electrode portion is a cathode, the other electrode portion is an anode.

Further, one of the electrode portions with which the contact member comes into contact may be constituted by a pedestal having a holding hole, and the holding resistor may hold the protective resistor, and the protective resistor is rod-shaped and extends vertically in the holding hole. May be retained. Further, the protective resistor may be pressed and held in the holding hole.

Furthermore, a conductive cap may be covered on the pedestal side of the protective resistor, and the pedestal-side conductive cap may be pressure-bonded and held by a holding hole, and the other electrode portion not in contact with the pad member. May be integrally formed with the protective resistor.

Further, the protective resistor may be covered with a conductive cap on the skin contact side, and the other electrode portion may be formed on the conductive cap on the skin contact side, and the other conductive cap on the pedestal side. An electrode which is the same electrode material as the electrode part and which does not come into skin contact during use may be formed.

Further, one of the electrode portions contacting the contact member may be an anode portion, and the pedestal may be a synthetic resin having a surface plated with a precious metal such as gold.

The holding groove of the pedestal may be formed so as to surround the holding hole, and a rod-shaped conductor may be used instead of the protective resistor.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of an embodiment of the iontophoresis device of the present invention. The iontophoresis element is
Anode part 1 made of conductive metal, cathode part 2 made of semiconductor
(2a, 2b), a protective resistor 3 electrically connecting between the anode part 1 and the cathode part 2a and having a voltage control function, a pad member 4 impregnated with a negative ionic drug, and a conductive cap 5a. 5b, and can be skin-contacted as a seal by the adhesive cloth 6.

The anode part 1 is formed by plating a synthetic resin pedestal with a noble metal such as gold.
It is preferable that this plating is applied to the entire surface, but it is sufficient that the contact member 4 and the conductive cap 5b (base side) are electrically connected. The anode part 1 becomes an anode during use. Incidentally, the anode part 1 may be one in which the pedestal itself is formed of a conductive metal, but the manufacturing cost can be reduced by plating the pedestal as in this embodiment. The plating may be an alloy instead of a noble metal such as gold or platinum. Anode part 1
The holding hole 1a and the holding groove 1b formed above will be described later.

The cathode part 2 is a conductive cap 5a (on the skin contact side).
It is formed on the cathode (cathode part 2a), but is also formed on the conductive cap 5b (base side) as in this embodiment (cathode part 2b).
It does not matter if it is done. By forming also on the conductive cap 5b in this way, the permeation anion on the pad member 4 can be easily permeated into the skin, and the protective resistor 3 in the state of being covered with the conductive cap 5 at the time of manufacturing is further provided. When pressing into the holding hole 1a, it is not necessary to distinguish between upper and lower parts, which facilitates manufacturing. The cathode portion 2b is not arranged so as to be in skin contact during use, but is in contact with the adhesive cloth 6 as shown in the drawing, and is short-circuited with the anode portion 1. The semiconductor that constitutes the cathode part 2 (2a, 2b) is, for example, one type selected from the group consisting of zinc oxide, aluminum oxide, bismuth oxide, iron oxide, lead oxide, antimony oxide, titanium oxide, and tin oxide. There are oxygen-deficient oxides. Further, it may have a double structure in which only the skin contact surface is a semiconductor and the lower layer is a metal.

The protective resistor 3 is formed in a rod shape. The protective resistor 3 is, for example, a ceramic rod whose surface is coated with carbon, and the resistance value that determines the current value can be arbitrarily set by the coating amount. Further, the protective resistor 3 is covered with conductive caps 5 (5a, 5b) on both ends thereof, that is, the skin contact portion 3a and the base portion 3b. Further, the protective resistor 3 is mounted in the holding hole 1a of the pedestal 1 in the vertical direction (standing state), and the base portion 3b is press-fitted and fixed in the holding hole and electrically connected to the pedestal 1.
The protective resistor 3 can form an iontophoresis element without being a resistor, and in this case, the protective resistor 3 is a rod-shaped conductor.

The backing member 4 is formed of a pad made of, for example, a non-woven fabric, in which the permeation anionic drug is dispersed. The contact member 4 is electrically insulated from the cathode portion 2 (2a, 2b).

The conductive caps 5a and 5b are made of a conductive material (for example, iron), and the conductive caps 5a and 5b are respectively placed on the skin contact portion 3a and the base portion 3b of the protective resistor 3 so as to cover the conductive caps. The cathode portion 2 (2a, 2b) is formed by forming an oxide semiconductor made of, for example, zinc oxide on the surfaces of 5a, 5b. This oxide semiconductor becomes a cathode when used. Such an oxide semiconductor 2
The protective resistor 3 including the conductive cap 5 forming (2a, 2b) has the same structure as a resistor, which is an electronic component, for example, and can be supplied in large quantities at low cost.
The cathode portion 2 (2a, 2b) is the base portion 3b of the protective resistor 3.
The skin contact portion 3a may be integrally formed without the conductive cap 5 (5a, 5b) interposed.

The abutting member 4 is mounted in the holding groove 1b provided in the pedestal 1, and the protective resistor 3 is arranged in the hole 4a.

An adhesive cloth 6 is attached to the lower surface of the anode part 1. Adhesive is applied to the upper surface of the adhesive cloth 6, which holds the pedestal 1 and can be attached to the skin as a seal so that the cathode portion 2a and the contact member 4 are in skin contact during use.

FIG. 2 is a plan view of an embodiment of the iontophoresis device of the present invention.

On the skin contact side of the anode part 1 (upper surface in FIG. 1), a holding hole 1a serving as a holding part for holding the protective resistor 3 is formed in the central part, and the holding hole 1a is formed outside the holding hole. Holding hole 1
A holding groove 1b serving as a holding portion for holding the contact member 4 is formed so as to surround a. The rod-shaped conductive cap 5 is formed so as to come into contact with the holding hole 1a having a rectangular prism shape having a quadratic cross section.
Is crimped. The holding groove 1b is formed in an annular shape centered on the holding hole 1a, and the abutting member 4 is arranged between the outer side surface and the inner side surface of the holding groove 1b.

FIG. 3 is an enlarged front view of a partial cutaway showing an exploded state of an embodiment of the iontophoresis device of the present invention. Anode part 1 which is a pedestal and conductive caps 5a, 5
It is shown in a state where the protective resistor 3 covered with b and the contact member 4 are disassembled, and the anode part 1 and the protective resistor 3 are notched on the left side from the center. The hatched portion is a cross section when cut out. Since this embodiment is symmetrical to the left and right, the same cross section appears when the right side is cut away. In the present embodiment, the conductive caps 5a, 5
The protective resistor 3 covered with b may be pressed upside down, but in the case where the cathode portion 2b is not formed on the conductive cap 5b and only the cathode portion 2a is formed. Is a conductive cap 5a so that the cathode part 2a is in skin contact.
Care must be taken to position it so that it is at the top.

FIG. 4 is a sectional view taken along line XX of FIG. 3, showing a section of the anode part 1. The hatched portion in the drawing is a cross section, the holding hole 1a has a quadrangular horizontal cross section, and the holding groove 1b is formed in an annular shape centered on the holding hole 1a.
In the drawing, the cross section of the side surface of the holding groove 1b and the holding hole 1a is shown.

FIG. 5 is a sectional view taken along the line YY of FIG. 3, showing a section of the contact member 4. The shaded area in the figure is the cross section. As shown in the figure, the pad member 4 has a hole 4 at the center.
It has a ring shape in which a is penetrated. When the iontophoresis element is formed, the contact member 4 is arranged so that its cross section is substantially concentric with the protective resistor 3 and the conductive cap 5 shown by the dotted line.

The usage of one embodiment of the iontophoresis device is shown in FIG. With the adhesive cloth 6, the conductive cap 5 on the upper surface of the pad member 4 and the skin contact portion 3a side of the protective resistor 3
When these are skin-contacted simultaneously, an external circuit short-circuit type chemical battery consisting of an anode (base 1 which is an anode part), a cathode (cathode part 2a) and an electrolyte (a patch member 4 and skin 7) is formed at the skin-contact part.

In this case, the energization path is a closed circuit of cathode part 2a → (protective resistor 3) → anode part 1 → abutting member 4 → skin 7 → cathode part 2a. The permeation anionic drug in the pad member 4 receives the two-dimensional electric repulsive force by the electrons flowing from the anode part 1 to the cathode part 2a and permeates into the skin 7. The electrons penetrating into the skin 7 together with the permeation anionic drug cause a reduction reaction. On the other hand, in the cathode portion 2a where the electrons have flown out, the excess holes permeate into the skin 7 due to the internal electric field of the Schottky barrier formed on the contact surface and cause an oxidation reaction. Since the Schottky barrier blocks the inflow of electrons from the contact surface, a stable electromotive force of the bio-cell can be obtained.

Further, by short-circuiting the cathode portion 2b and the anode portion 1, it is expected that the effect of penetrating the anionic drug into the skin will be improved.

In the above embodiment, the anode part 1 is a synthetic resin molded product plated with metal, and the protective resistor 3 is a ceramic rod whose surface is coated with carbon. It is possible to mass-produce elements and reduce manufacturing costs, and by integrating the cathode part made of semiconductor in the manufacturing process with the protective resistor, it is possible to suppress skin damage caused by changes in skin resistance during use. it can.

In the embodiments described with reference to FIGS. 1 to 6, the ionic drug impregnated in the patch member 4 is a negative ion to the skin. In order to allow a drug that becomes a positive ion to the skin to penetrate into the skin according to the present invention, the electrode portion that serves as the pedestal must be reversed from that in the above embodiment. That is, in the figure, 1 is used as a cathode part
2b) is the anode part. In this case, if there is a possibility that the contacting cathode portion of the backing member will react with an ionic drug and oxidize, the surface of the cathode portion should be coated beforehand with a thin film of a chemically stable conductive material such as conductive carbon. You may make it contact with the abutting member 4. In this case, if the surface of the anode part is also coated with the same conductive substance, the influence of the coating substance on the electromotive force can be offset.

[0035]

According to the present invention, by providing the protective resistor, it is possible to prevent the damage of the skin due to the increase of the electric current.
In addition, since the structure has no conductive structure, it is very easy to manufacture and can be mass-produced.

Further, since the rod-shaped protective resistor can be used as it is as a resistor as a commonly used electronic component, it can be supplied in large quantities at low cost, and the anode can be plated with a noble metal. Can be reduced and the manufacturing process can be simplified.

Further, by providing a cathode which is short-circuited with the anode, the ion penetration effect can be enhanced.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the iontophoresis device of the present invention.

FIG. 2 is a plan view of an embodiment of the iontophoresis device of the present invention.

FIG. 3 is an enlarged front view of a notch showing an exploded state of an embodiment of the iontophoresis device of the present invention.

4 is a sectional view taken along line XX of FIG.

5 is a cross-sectional view taken along the line YY of FIG.

FIG. 6 is a sectional view showing a usage state of an embodiment of the iontophoresis device of the present invention.

FIG. 7 is a plan view showing a conventional iontophoresis device.

8 is a sectional view taken along line ZZ in FIG.

[Explanation of symbols]

1 Anode part 1a holding hole 1b retaining groove 2a Cathode part (skin contact side) 2b Cathode part (base side) 3 protective resistor 3a Skin contact part 3b base 4 Resting member 4a hole 5a Conductive cap (skin side) 5b Conductive cap (base side) 6 adhesive cloth 7 skin 11 Metal anode 12 Semiconductor cathode 14 pads 15 conductors

Claims (11)

[Claims] 1. An anode part made of a conductive metal, a cathode part made of a semiconductor, a protective resistor electrically connecting the anode part and the cathode part and having a current limiting function, and an ionic property. And a contact member impregnated with a drug, wherein the contact member is in contact with either one of the anode part and the cathode part, and the other electrode part and the contact member are simultaneously peeled during use. An iontophoresis element characterized by being arranged so as to be in contact with each other. 2. The iontophoresis device according to claim 1, wherein the one electrode portion is formed of a pedestal having a holding hole, and the holding resistor holds the protective resistor. 3. The iontophoresis device according to claim 2, wherein the protective resistor is rod-shaped and is held in the holding hole in a vertical direction. 4. The iontophoresis element according to claim 2, wherein the protective resistor is pressure-bonded and held in the holding hole. 5. The ion according to claim 2, wherein the pedestal side of the protective resistor is covered with a conductive cap, and the pedestal side conductive cap is press-fitted and held in the holding hole. Tophoresis element. 6. The iontophoresis device according to claim 1, wherein the other electrode portion is integrally formed with a protective resistor. 7. The protective resistance body is covered with a conductive cap on the skin contact side, and the other electrode portion is formed on the conductive cap on the skin contact side. The iontophoresis device described in 1. 8. The iontophoresis device according to claim 7, wherein an electrode made of the same electrode material as the other electrode portion and not in skin contact during use is formed on the pedestal-side conductive cap. 9. The method according to claim 2, wherein the one electrode portion is the anode portion, and the pedestal is a synthetic resin having a surface plated with a precious metal such as gold. Iontophoresis element. 10. An anode part made of a conductive metal, a cathode part made of a semiconductor, and a protective resistor electrically connecting the anode part and the cathode part and having a current limiting function.
And a pad member impregnated with an ionic drug,
The aforesaid contact member is an iontophoresis element arranged so as to come into contact with either one of the anode part or the aforesaid cathode part, and the other electrode part and the aforesaid contact member are in skin contact at the same time during use, The one electrode part is a pedestal,
The pedestal has a holding groove and a holding hole, the holding groove is formed so as to surround the holding hole, the protective resistor is rod-shaped and vertically held in the holding hole, the abutting member is An iontophoresis device characterized by being held in the holding groove. 11. An anode part made of a conductive metal, a cathode part made of a semiconductor, a rod-shaped conductor for electrically connecting the anode part and the cathode part, and an impregnated ionic drug. And a contact member, wherein the contact member is in contact with any one of the anode part or the cathode part,
An iontophoresis element arranged such that the other electrode portion and the contact member are in skin contact at the same time during use,
The one electrode portion is a pedestal, and the pedestal has a holding groove and a holding hole, the holding groove is formed so as to surround the holding hole, and the rod-shaped conductor is vertically held in the holding hole. And the abutting member is held by the holding groove.