Iontophoretic treatment system

• US 5,224,927 A
• Filed: 11/01/1990
• Issued: 07/06/1993
• Est. Priority Date: 11/01/1990
• Status: Expired due to Term

• Current Assignee: Robert Tapper
• Original Assignee: Robert Tapper
• Inventors: Tapper, Robert
• Primary Examiner(s): Pellegrino, Stephen C.
• Assistant Examiner(s): Rafa, Michael
• Application Number:
  US07/607,874
• Time in Patent Office: 978 Days
• Field of Search: 604/20, 604/783, 128/798, 128/802, 128/803
• US Class Current: 604/20
• CPC Class Codes: A61N 1/044 Shape of the electrode
• CPC Class Codes: A61N 1/0444 Membrane
• CPC Class Codes: A61N 1/0448 Drug reservoir
• CPC Class Codes: A61N 1/303 Constructional details electrodes for external use A61N1/0428
• CPC Class Codes: A61N 1/325 for iontophoresis, i.e. transfer of media in ionic state by an electromotoric force into the body electrodes for external use A61N1/0428

Abstract

A method and apparatus for applying iontophoretic treatment to a biological subject wherein electrical treatment current between a pair of electrodes is periodically reversed at very low frequencies, substantially in the range of approximately 0.0027 Hz to approximately 10 Hz, to mitigate tissue damage, enable long term dosimetry with single and multiple drugs of any polarity and at higher concentrations, and eliminate the need for buffering agents and the like, all in a relatively simple, economical and compact physical packaging configuration. The system delivers treatment substances with large and/or small molecular size and weight and can be adjusted to control pH at the delivery site. A method of lowering resistance and enhancing permeability at the delivery site is also provided.

Claims

1. A method of applying iontophoretic treatment to a biological subject, said method including the steps of:

conducting an electrical current through a surface of said subject in a first direction from a first electrode to a second electrode on said subject; and

intermittently reversing, at a relatively low frequency which prevents skin damage, between approximately 20 times per second and approximately once every three minutes, the polarity of said electrodes to cause said electrical current to flow in a second direction opposite to said first direction, whereby iontophoretic treatment may be continuous for extended periods of time.

2. A method as set forth in claim 1, including the step of:

selectively varying the amplitude of the electrical current in one direction relative to the amplitude of the electrical current in the opposite direction to control pH at the surface of said subject.

3. A method as set forth in claim 1, including the step of:

selectively varying the frequency of the electrical current to accommodate the transport times of different size molecules.

4. A method as set forth in claim 1, wherein multiple drugs are delivered.

5. A method as set forth in claims 1 or 4, wherein drugs of the opposite polarity are delivered simultaneously.

6. A method as set forth in claim 1 or 4, wherein drugs of the same polarity are driven alternately from different electrodes.

7. A method as set forth in claim 1, wherein a carrier of opposite polarity is added to a drug to be driven by at least one of said electrodes.

8. A method of clearing ionic clutter from an iontophoretic drug administration system, said method including the steps of:

conducting an electrical current through a surface of a subject being treated, in a first direction from a first electrode to a second electrode on said subject; and

periodically reversing, at a relatively low frequency which avoids damage to said subject, between approximately 20 times per second and approximately once every three minutes, the polarity of said electrodes to cause said electrical current to flow in a second direction opposite to said first direction, whereby the resulting very low frequency alternating current eliminates ionic clutter and facilitate continuous drug administration for extended periods of time.

9. A method of iontophoretic infusion of medical substances into a biological subject, comprising the steps of:

locating a pair of electrically conductive electrodes adjacent to a surface of said subject to be treated;

placing at least one medical substance between at least one of said electrodes and said surface of said subject to be treated;

conducting an electrical current through said surface of said subject in a first direction from a first of said electrodes to a second of said electrodes on said subject; and

periodically and regularly reversing, at a relatively low frequency, between approximately 20 times per second and approximately once every three minutes, the polarity of said electrodes to cause said electrical current to flow in a second direction opposite to said first direction, whereby skin damage to said subject is avoided and drug infusion may be continuous for extended periods of time.

10. A method as set forth in claim 9, including the step of:

selectively varying the amplitude of the electrical current in one direction relative to the amplitude of the electrical current in the opposite direction to control pH at the surface of said subject.

11. A method as set forth in claim 9, including the step of:

selectively varying the frequency of the electrical current to accommodate the transport times of different size molecules.

12. A method as set forth in claim 9, wherein multiple medical substances are delivered.

13. A method as set forth in claims 9 or 12, wherein medical substances of the opposite polarity are delivered simultaneously.

14. A method as set forth in claims 9 or 12, wherein medical substances of the same polarity are driven alternately from different electrodes into said surface.

15. A method as set forth in claim 9, wherein a carrier substance of opposite polarity is added to a medical substance to be driven by at least one of said electrodes.

16. A method as set forth in claim 9, including the additional step of:

iontophoretically delivering a surfactant material into said surface to lower electrical resistance and enhance drug penetration.

17. A method as set forth in claim 9, including the additional step of:

iontophoretically delivering an amphoteric surfactant material into said surface to lower electrical resistance and enhance drug penetration.

18. A method as set forth in claim 9, including the additional step of:

iontophoretically delivering a cationic surfactant material into said surface to lower electrical resistance and enhance drug penetration.

19. A method of iontophoretic infusion of medical substances into a biological subject, comprising the steps of:

locating a pair of electrically conductive electrodes upon said subject to be treated;

placing at least one medical substance between at least one of said electrodes and a surface of said subject to be treated;

conducting an electrical current through said surface of said subject in a first direction from a first of said electrodes to a second of said electrodes on said subject; and

intermittently reversing the polarity of said electrodes to cause said current to flow in a second direction opposite to said first direction, at a relatively low frequency which prevents skin damage to said subject and simultaneously provides adequate molecular transport time for said medical substance to be delivered into said surface of said subject, whereby infusion of said medical substance may be continuous for extended periods of time and wherein the polarity reversal occurs after the accumulated time periods of actual substantial electrical current flow in either direction equal a selected period of time between approximately 0.05 seconds and approximately 3 minutes.