Transdermal administrating device

• US 6,622,037 B2
• Filed: 04/03/2001
• Issued: 09/16/2003
• Est. Priority Date: 04/05/2000
• Status: Expired due to Fees

• Current Assignee: Polytronics Limited
• Original Assignee: Polytronics Limited
• Inventors: Kasano, Hiroyuki
• Primary Examiner(s): KENNEDY, SHARON E
• Application Number:
  US09/825,007
• Publication Number:
  US 20010029347A1
• Time in Patent Office: 896 Days
• Field of Search: 604/20, 604/289, 604/290, 604/501, 607/149, 607/115
• US Class Current: 604/20
• CPC Class Codes: A61N 1/30 Apparatus for iontophoresis, i.e. transfer of media in ionic state by an electromotoric force into the body, or cataphoresis

Abstract

A transdermal administrating device is provided which includes an active electrode having a conductive electrode layer and a conductive drug layer applied on the bottom surface of the conductive electrode layer. The bottom surface of the conductive drug layer is capable of being placed in contact with skin. The device also includes an inert electrode capable of being placed in contact with skin and spaced from the active electrode, a set of conductive electrode layers each having a different standard single electrode potential, and a controller for measuring an internal resistance of the skin tissue under the region between the conductive electrode layers and for controlling an electric current passing between the active electrode and the inert electrode based on the variation in the internal resistance. In addition, a dermocontact mechanism is provided for keeping the active electrode, the inert electrode, and the set of conductive electrode layers in contact with skin.

Claims

1. A transdermal administrating device comprising:

an active electrode having a conductive electrode layer and a conductive drug layer applied on one surface of said conductive electrode layer, said conductive drug layer being capable of being placed in contact with skin;

an inert electrode which is made of a conductive material, and which is capable of being placed in contact with skin and spaced from said active electrode;

means for applying a variable bias voltage across said active electrode and said inert electrode;

a set of first and second conductive electrode layers which are each made of a material having a different standard single electrode potential, and which are capable of being placed in contact with skin and spaced from each other;

a controller connected to said first and said second conductive electrode layers in a non-dermocontact region for measuring an internal resistance of skin tissue between said first and said second electrode layers, said internal resistance being distinct from a contact resistance and a leak resistance between the first and second conductive electrode layers, and controlling an electric current passing through the skin tissue between said active electrode and said inert electrode based on said measured internal resistance; and

dermocontact means for keeping said active electrode, said inert electrode, and said set of said first and said second electrodes in contact with skin.

2. The transdermal administrating device according to claim 1, wherein said controller is held by said dermocontact means.

3. The transdermal administrating device according to claim 1, wherein:

said means for applying the variable bias voltage comprises a variable bias power supply connected between said active electrode and said inert electrode in a non-dermocontact region, and

said controller comprises;

a measurement circuit for measuring said internal resistance, and

a controlling circuit for instructing said measurement circuit to measure said internal resistance, calculating a bias voltage to be applied between said active electrode and said inert electrode based on said measured internal resistance value, and instructing said variable bias power supply to apply said calculated bias voltage across said active electrode and said inert electrode.

4. The transdermal administrating device according to claim 1, wherein:

said means for applying the variable bias voltage comprises a variable resistor connected between said active electrode and said inert electrode,

a material constituting said conductive electrode layer of said active electrode and said material constituting said inert electrode have different standard single electrode potentials from each other, and

said controller comprises;

a measurement circuit for measuring said internal resistance connected between said first and second conductive electrode layers in the non-dermocontact region, and

a controlling circuit for instructing said measurement circuit to measure said internal resistance, calculating a resistance value to be set onto said variable resistor based on said measured internal resistance value, and controlling said variable resistor to be at said calculated resistance value.

5. The transdermal administrating device according to claim 3, wherein:

said measurement circuit comprises standard resistors including first and second standard resistors which are different from each other, and

said measurement circuit contains both a switch for selecting which of said first and said second standard resistor is connected to the external circuit between said first and second conductive electrode layers, and a voltage meter for measuring voltages between opposite ends of said first and said second standard resistors when connected to said external circuit.

6. The transdermal administrating device according to claim 4, wherein:

said measurement circuit comprises standard resistors including first and second standard resistors which are different from each other, and

said measurement circuit contains both a switch for selecting which of said first and said second standard resistors is connected to the external circuit between said first and second conductive electrode layers, and a voltage meter for measuring a voltage between opposite ends of said first or said second standard resistor when connected to said external circuit.

7. The transdermal administrating device according to claim 1, wherein:

said dermocontact means comprises a plurality of openings and first and second sides, said active electrode, said inert electrode, said first conductive electrode layer and said second conductive electrode layer are adhered on the first side of said dermocontact means,

said controller and said bias power supply or said variable resistor are provided on the second side of said dermocontact means, and connected between said first conductive electrode layer and said second conductive electrode layer, or between said active electrode and said inert electrode through said openings.

8. The transdermal administrating device according to claim 2, wherein:

said dermocontact means comprises a plurality of openings and first and second sides,

said active electrode, said inert electrode, said first conductive electrode layer and said second conductive electrode layer are adhered on the first side of said dermocontact means,

said controller and said bias power supply or said variable resistor are provided on the second side of said dermocontact means, and connected between said first conductive electrode layer and said second conductive electrode layer, or between said active electrode and said inert electrode through said openings.

9. The transdermal administrating device according to claim 3, wherein:

said dermocontact means comprises a plurality of openings and first and second sides,

said active electrode, said inert electrode, said first conductive electrode layer and said second conductive electrode layer are adhered on the first side of said dermocontact means,

said controller and said bias power supply or said variable resistor are provided on the second side of said dermocontact means, and connected between said first conductive electrode layer and said second conductive electrode layer, or between said active electrode and said inert electrode through said openings.

10. The transdermal administrating device according to claim 1, wherein another conductive material is further coated between at least one of said first and said second conductive electrode layer and the skin.

11. The transdermal administrating device according to claim 2, wherein another conductive material is further coated between at least one of said first and said second conductive electrode layer and the skin.

12. The transdermal administrating device according to claim 3, wherein another conductive material is further coated between at least one of said first and said second conductive electrode layer and the skin.

13. The transdermal administrating device according to claim 1, wherein said active electrode acts also as said first conductive electrode layer and/or said inert electrode acts also as said second conductive electrode layer.

14. The transdermal administrating device according to claim 2, wherein said active electrode acts also as said first conductive electrode layer and/or said inert electrode acts also as said second conductive electrode layer.

15. The transdermal administrating device according to claim 3, wherein said active electrode acts also as said first conductive electrode layer and/or said inert electrode acts also as said second conductive electrode layer.

16. The transdermal administrating device according to claim 1, wherein among said materials constituting said first conductive electrode layer and said second conductive electrode layer, the material having a lower standard single electrode potential comprises an n-type semiconductor.

17. The transdermal administrating device according to claim 2, wherein among said materials constituting said first conductive electrode layer and said second conductive electrode layer, the material having a lower standard single electrode potential comprises an n-type semiconductor.

18. The transdermal administrating device according to claim 3, wherein among said materials constituting said first conductive electrode layer and said second conductive electrode layer, the material having a lower standard single electrode potential comprises an n-type semiconductor.

19. A method of transdermal administration comprising:

(a) attaching on a skin surface each of;

(i) an active electrode having a conductive electrode layer and a conductive drug layer applied on one surface of said conductive electrode layer, (ii) an inert conductive electrode which is spaced from said active electrode, and (iii) a set of spaced apart conductive electrode layers each made of a material having a different standard single electrode potential,

(b) detecting an electric current passing through a subcutaneous tissue between said set of conductive electrode layers, and detecting an internal resistance of said subcutaneous tissue, said internal resistance being distinct from a contact resistance and a leak resistance between the spaced apart conductive electrode layers,

(c) determining said internal resistance for keeping a concentration of a delivered drug in said subcutaneous tissue at a desired level based on a predetermined calibration line representing a relationship between a concentration in blood of the delivered drug and said internal resistance, and

(d) controlling said electric current passing through said active electrode, said subcutaneous tissue, and said inert electrode so as to maintain said internal resistance.

20. A transdermal administration device comprising:

a transdermal administration unit for carrying out iontophoresis, including an active electrode provided with a conductive drug layer, an inert electrode, and a variable bias voltage source for applying a variable bias voltage across said active electrode and said inert electrode;

a detection unit including a set of detection electrodes made of conductive materials having different standard single electrode potential, said detection electrodes being adapted to be brought into contact with a patient'"'"'s skin at separated locations, and an external load connected to said set of detection electrodes, said external load comprising standard resistors to be alternatively connected to a circuit including said detection electrodes, a change-over switch for changing over said standard resistors, and a voltage meter for detecting voltage drops across respectively connected ones of the standard resistors;

a controller unit receiving the voltage drops and generating a control signal based on an internal resistance of a skin calculated from the voltage drops, said internal resistance being distinct from a contact resistance and a leak resistance between the detection electrodes, for controlling said variable bias voltage source.