Methods and architecture for power optimization of iontophoretic transdermal drug delivery

• US 8,986,279 B2
• Filed: 02/09/2011
• Issued: 03/24/2015
• Est. Priority Date: 02/10/2010
• Status: Active Grant

• Current Assignee: InCube Labs LLC. (In-Cube, Inc.)
• Original Assignee: InCube Labs LLC. (In-Cube, Inc.)
• Inventors: Imran, Mir, Andersen, Dean P., Malhotra, Vikram, Mangogna, George Andrew
• Primary Examiner(s): Bosworth, Kami A
• Application Number:
  US13/024,295
• Publication Number:
  US 20110196283A1
• Time in Patent Office: 1,504 Days
• Field of Search: 604/20, 604/21, 604/501
• US Class Current: 604/501
• CPC Class Codes: A61N 1/044 Shape of the electrode
• 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
• CPC Class Codes: A61P 3/00 Drugs for disorders of the metabolism of the blood or the extracellular fluid A61P7/00
• CPC Class Codes: A61P 3/10 for hyperglycaemia, e.g. antidiabetics

Abstract

Embodiments of the invention provide an architecture, system and methods for optimizing power utilization for transdermal iontophoretic drug delivery which maintain a iontophoretic driving voltage at a reduced or even minimum value to support an iontophoretic delivery current. The reduced voltage reduces the power requirements for a transdermal iontohoretic delivery system during a period of drug delivery. Embodiments of an architecture for implementing this approach can utilize a controller which compares the desired current to the actual current and adjusts the voltage to reduce the amount of power used for iontophoretic drug delivery. The controller can comprise a state machine or microprocessor. Embodiments of the invention are particularly useful for extending the battery life of transdermal iontophoretic drug delivery systems.

Claims

1. A method for optimizing power for iontophoretic transdermal delivery of a therapeutic agent to a patient in need thereof, the method comprising:

applying a patch to the skin of the patient, the patch comprising a therapeutic agent and at least one electrode;

coupling the at least one electrode to a power source;

delivering a current to the skin from the patch to transport the therapeutic agent into the skin;

measuring a delivered current in a circuit comprising the patient and the power source;

comparing the measured current to a desired current; and

adjusting a voltage responsive to the comparison, wherein decreases in the voltage are made after a wait period to determine if the desired current is achieved; and

wherein the voltage is adjusted to achieve and maintain the desired current while minimizing power delivered from the power source.

2. The method of claim 1, wherein power from the power source is reduced by up to about 45 percent by adjustment of the voltage.

3. The method of claim 1, wherein power from the power source is reduced by up to about 60 percent by adjustment of the voltage.

4. The method of claim 1, wherein the therapeutic agent comprises an iron containing compound for the treatment of iron deficiency anemia.

5. The method of claim 1, wherein the therapeutic agent comprises insulin or a glucagon-like peptide for the treatment of a blood sugar regulation disorder.

6. The method of claim 1, wherein the therapeutic agent comprises fentanyl or an opioid for pain management.

7. The method of claim 1, further comprising measuring an electrical property of a circuit comprising the patient and the power source.

8. The method of claim 7, wherein the electrical property is measured over a range of frequencies.

9. The method of claim 8, wherein the range of frequencies is from about 0.01 to about 1000 hz.

10. The method of claim 8, wherein the electrical property is measured using a sensor.

11. The method of claim 10, wherein the sensor is coupled to at least one of the power source or a controller coupled to the power source.

12. The method of claim 10, wherein the sensor is positioned on or in the patch.

13. The method of claim 10, wherein the sensor comprises the at least one electrode.

14. The method of claim 7, wherein the electrical property is measured in a substantially continuous fashion during a period when current is delivered to the skin.

15. The method of claim 7, wherein the electrical property is measured at fixed intervals during a period when current is delivered to the skin.

16. The method of claim 15, wherein an interval duration is in a range of about 0.001 to 1 second.

17. The method of claim 15, wherein a period between intervals is in a range of about 0.001 to 1 second.

18. The method of claim 1, wherein the power source is an electrochemical battery and battery life is extended by adjustment of the voltage.

19. The method of claim 18, wherein the battery is a lithium or alkaline battery.

20. The method of claim 18, wherein a battery voltage or current is maintained above a minimum level for a therapeutic agent delivery period as a result of the minimized delivered power.

21. The method of claim 20, wherein the delivery period is up to about one week.

22. The method of claim 20, wherein the delivery period is up to about two weeks.

23. The method of claim 18, wherein the current has a frequency in a range from about 0.5 to 100 Hz.

24. The method of claim 1, wherein the current is an alternating current.

25. The method of claim 1, wherein the voltage is adjusted using a controller.

26. The method of claim 25, wherein the controller is an analog device, a state machine, a digital controller or a microprocessor.

27. The method of claim 25, wherein the controller utilizes a software module to adjust the voltage.

28. A method for optimizing power for iontophoretic transdermal delivery of a therapeutic agent to a patient in need thereof, the method comprising:

applying a patch to the skin of the patient, the patch comprising a therapeutic agent and at least one electrode;

coupling the at least one electrode to a power source;

delivering a selected current to the skin from the patch to transport the therapeutic agent into the skin;

measuring an electrical impedance of the patient;

comparing the measured impedance to a desired impedance; and

adjusting a voltage responsive to the comparison, wherein decreases in the voltage are made after a wait period to determine if the desired impedance is achieved and wherein the voltage is adjusted to maintain the selected current while minimizing power delivered from the power source.

29. The method of claim 28, wherein the impedance is measured in a volume of tissue between the at least one electrode and a return electrode applied to the skin of the patient.

30. The method of claim 28, wherein the impedance is measured in a circuit comprising at least two of the at the least one electrodes, the patient'"'"'s tissue and the power source.

31. A method for optimizing power for iontophoretic transdermal delivery of a therapeutic agent to a patient in need thereof, the method comprising:

applying a patch to the skin of the patient, the patch comprising a therapeutic agent and at least one electrode;

coupling the at least one electrode to a power source;

delivering a current to the skin from the patch to transport the therapeutic agent into the skin;

measuring a delivered current and another electrical property in a circuit comprising the patient and the power source;

comparing the measured current to a desired current; and

adjusting a voltage responsive to the comparison and the other electrical property, wherein decreases in the voltage are made after a wait period to determine if the desired current is achieved, and wherein the voltage is adjusted to achieve and maintain the desired current while minimizing power delivered from the power source.

32. The method of claim 31, wherein the other electrical property is one of a skin impedance, a skin resistance, a lumped impedance, a lumped resistance or a delivered current.