Iontophoretic drug delivery device having high-efficiency DC-to-DC energy conversion circuit

• US 6,402,732 B1
• Filed: 09/05/2000
• Issued: 06/11/2002
• Est. Priority Date: 08/29/1995
• Status: Expired due to Fees

• Current Assignee: Vyteris, Inc.
• Original Assignee: Vyteris, Inc.
• Inventors: Devine, James Michael, Flower, Ronald J.
• Primary Examiner(s): Bockelman, Mark
• Application Number:
  US09/655,138
• Time in Patent Office: 644 Days
• Field of Search: 604/20-21, 604/501
• US Class Current: 604/501
• 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

An iontophoresis system includes a transdermal patch for placement against the skin of a patient and a controller electrically connected to the patch. The patch includes an anode and cathode electrode, and holds an electrolyte and a medication. The controller includes a DC-DC converter circuit which generates an output voltage that is provided to the anode electrode. The controller also includes an adjustable current regulator circuit. The current regulator circuit is coupled to the cathode electrode and is adjustable to provide a desired current flow through the electrodes and the skin of the patient. The DC-DC converter circuit is responsive to the voltage drop across the electrodes and adjusts its output voltage in response to this voltage drop and changes in the impedance of the patient'"'"'s skin.

Claims

1. A method for providing a self-regulating voltage and current to an iontophoretic drug delivery device of an iontophoresis system to minimize the use of power by the system, the iontophoretic drug delivery device being placeable on the skin of a patient and including a first electrode and a second electrode, the method comprising the steps of:

generating a voltage V2 provided to the first electrode;

generating a desired drug delivery current to flow through the first and second electrodes and the skin of a patient, the desired drug delivery current being generated by a current regulator circuit having a voltage drop Vs thereacross, the impedance of at least one of the iontophoretic drug delivery device and the patient'"'"'s skin and the desired drug delivery current flowing therethrough resulting in a voltage drop Vp across the first and second electrodes, the voltage V2 being equal to the sum of the voltage Vp and the voltage Vs;

adjusting the voltage V2 in response to a change in the voltage drop Vp across the first and second electrodes so that voltage drop Vs is maintained at a minimum voltage level required to allow the current regulator circuit to control the desired drug delivery current through the at least first and second electrodes and the skin of the patient and to minimize the use of power by the iontophoresis system.

2. A method as defined by claim 1, which further comprises the step of:

preventing the voltage V2 from increasing above a predetermined level.