Title:  Iontophoresis device structure

United States Patent:  6,259,946

Assignee:  Hisamitsu Pharmaceutical Co., Ltd. (Saga-Ken, JP)

Filed:  September 27, 1999

PCT NO:  PCT/JP98/00323

102(e) Date:  September 27, 1999

PCT PUB. Date:  September 3, 1998

Foreign Application Priority Data:  Feb 26, 1997[JP] (9-060051)

It is the object of the present invention to provide an iontophoresis device structure which has excellent contouring ability at its site of attachment, has very high safety, is of high quality with high product yields, and can be produced with fewer production steps to improve working efficiency and increase productivity to allow mass production at low cost. The iontophoresis device structure of the present invention has a construction provided with a cup-shaped support including a concave part, at least one electrification hole formed in the concave part, an electrode layer laid on the flat part of the rim of the concave part, and an electrolyte layer or drug-holding layer fitted into the concave part.

DISCLOSURE OF THE INVENTION

The iontophoresis device structure according to claim 1 of the invention has a construction provided with a cup-shaped support including a concave part, at least one electrification hole formed in the concave part, an electrode layer formed on the flat part of the rim of the concave part, and an electrolyte layer fitted into the concave part.

Since the electrode layer is anchored on the outside of the flat part of the rim around the concave part of the support in this construction, its production is more simple allowing notable improvement in working efficiency, increasing productivity and lowering the cost. In addition, the adhesion between the flat part of the rim and the electrode layer around the concave part can be markedly increased, to help prevent leakage of the solvent of the electrolyte layer, etc.

Here, the support serves to hold the electrolyte layer, and it may be any material with excellent workability, flexibility and suitable shape retention and water retention; as examples there may be mentioned chlorinated resins such as vinylidene chloride and vinyl chloride polymers, as well as olefin-based, ester-based, styrene-based, acrylic-based, amide-based, oxymethylene-based, phenylene sulfide-based, amidoimide-based, acrylonitrile-based, etherketone, ethersulfone, sulfone, etherimide, butadiene and isoprene high molecular polymers or their copolymers, though there is no restriction to these and it is only necessary that the material have the effect mentioned above. Materials which have been formed into films and worked, or molded products, may be used. The thickness is not particularly restricted, but a thickness of 5-250 .mu.m is preferred for superior shape retention and flexibility.

The electrolyte layer is a conductive layer containing an electrolyte which supplies the body with a current from the power source when directly contacted with human skin or a mucous membrane, and it is preferred to use a nonwoven fabric impregnated with an electrolyte solution, or an electrolyte solution which has been gelled with a polysaccharide such as agar or gelled using a synthetic polymer.

The iontophoresis device structure according to claim 2 of the invention has the construction of claim 1 wherein the electrode layer is provided with an electrode layer base formed of a film or sheet of a thermoplastic synthetic resin, and a conductive layer formed on one side of the electrode layer base.

In this construction, the flexible electrode layer matches the soft support and can therefore follow the shape of the site of attachment. Also, since the electrode layer is made of an easily moldable synthetic resin, the number of production steps can be reduced to increase productivity.

The electrode layer base is a base sheet with a conductive layer on the bottom side, and its shape is not limited to circular but may be elliptical, square or rectangular; the electrode terminal may likewise have any desired shape, and if necessary a connector-anchoring cavity may be formed in the terminal for more stable anchoring with the connector, etc.

The material used for the electrode layer base may be the same material as the support. It is preferred to use an identical synthetic resin as the support in order to allow intimate heat sealing. Different types of synthetic resins may also be used depending on the position and material of the conductive layer.

The material used for the conductive layer may be metal foil, carbon foil or the like, but preferably a conductive ink paste is directly printed on a polymer sheet. As examples of such conductive ink paste materials there may be mentioned polarized electrode materials such as resin paints comprising mixtures of carbon powder or graphite powder, non-polarized materials such as silver- or copper-based materials for the anode and resin materials comprising silver/silver chloride, copper/copper chloride mixtures for the cathode; however, non-polarized materials which do not produce foaming under pH changes or electrolysis of water are particularly preferred for use.

The iontophoresis device structure according to claim 3 of the invention has the construction of claim 1 or 2 wherein the electrode layer is laid onto the flat part via an adhesive layer.

According to this construction, the electrode layer may be anchored to the surface of the flat part by simple adhesion with an adhesive agent, and since it is adhered on the outside of the support it is possible to prevent coating leakage of the adhesive agent and ensure anchorage of the electrode layer. Because the electrode layer and the cup-shaped support are thoroughly bonded, leakage and escape of the contents can be reliably prevented. The flexibility of the structure as a whole provides a better feel during use and makes it easier to design a line for mass production.

The iontophoresis device structure according to claim 4 of the invention has the construction of claim 3 wherein the adhesive agent of the adhesive layer is of one or more types from among acrylic-based, silicon-based or rubber-based pressure sensitive adhesive agents and heat sealing agents such as polyolefins or their esters.

According to this construction, the adhesive agent used is one which is commonly used, such as a pressure-sensitive adhesive agent which is an acrylic-based agent with high adhesive strength, a silicon-based agent which is resistant to corrosion in gel contents or an inexpensive rubber-based agent, or a heat sealing agent made of a polyolefin or its ester. These may be appropriately selected depending on the size and the purpose of use of the iontophoresis device structure. The adhesive agent accomplishes thorough sealing between the electrode layer and the flat part of the support, for a tight sealing effect.

When heat sealing is carried out for adhesion between the electrode layer and the cup, the heat sealing temperature will depend on the melting point of the aforementioned polymer film, but will generally be 100-250^oC., and preferably 120-200^oC. As the heat sealing temperature increases above 200^oC., cracks will tend to be produced in the electrode layer, while as it decreases below 120^oC. more time will be required for the heat sealing, which will tend to lower working efficiency, and therefore neither extreme is preferred.

The iontophoresis device structure according to claim 5 of the invention has the construction according to any one of claims 1 through 4, wherein the electrode layer has an electrification connecting member from the external power source, and the connecting member is a projection formed as a bulge from the rim of the electrode layer, or a recess formed parallel to the direction of height of the rim of the concave part of the support and the exposed part of the electrode layer which is exposed at the recess.

According to this construction, connection with the external power source for administration of the preparation can be simplified because of the projection provided.

Here, the size of the projection or exposed electrode layer as the connecting member may be a sufficient size or length to allow electrical connection with different types of connectors, and in order to prevent misconnection with the connector, a connector latch with a thickened end may be provided. A connection hole for the connector may also be opened in the projection or exposed electrode layer.

Claim 1 of 12 Claims

What is claimed is:

1. An iontophoresis device structure, characterized by being provided with a cup-shaped support including a concave part, at least one electrification hole formed in said concave part, an electrode layer laid on the flat part of the top outer rim of said concave part, and an electrolyte layer fitted into said concave part; and said electrode layer is provided with an electrode layer base formed of a film or sheet of a thermoplastic synthetic resin, and a conductive layer formed on one side of said electrode layer base facing the electrification hole.

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