Iontophresis system having features for reducing skin irritation
First Claim
1. An operable iontophoretic drug delivery system comprising:
- a drug reservoir adapted to be attached to the skin of an animal;
a first electrode in said drug reservoir;
an electrolyte reservoir adapted to be placed in communication with the skin of an animal;
a second electrode in said electrolyte reservoir;
circuit means for providing electrical communication between said first and second electrodes, said circuit means including means for connection to a source of electrical power;
means for providing substantially constant voltage between said electrodes, in said circuit means, including means for monitoring current through said first electrode;
means for providing substantially constant current to said first electrode, in said circuit means; and
switching means, in said circuit means, for switching from said means for providing constant voltage to said means for providing constant current when said current monitored by said monitoring means reaches a predetermined value.
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Accused Products
Abstract
An iontophoresis drug delivery system includes a device which is attachable to the skin of an animal and having a drug reservoir, an electrolyte reservoir, and electrodes electrically communicating with the reservoirs and with the skin of the animal. An electronic circuit for controlling the rate or amount of current or voltage applied to the electrodes of the device includes a constant voltage and current generator, and a switching circuit for switching between applying either a constant current to the electrodes or a constant voltage. Current and voltage sensors are attached to the electrodes and provide feedback signals which are compared with predetermined threshold signals to control through feedback the amount of constant voltage and constant current applied to the electrodes.
120 Citations
26 Claims
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1. An operable iontophoretic drug delivery system comprising:
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a drug reservoir adapted to be attached to the skin of an animal; a first electrode in said drug reservoir; an electrolyte reservoir adapted to be placed in communication with the skin of an animal; a second electrode in said electrolyte reservoir; circuit means for providing electrical communication between said first and second electrodes, said circuit means including means for connection to a source of electrical power; means for providing substantially constant voltage between said electrodes, in said circuit means, including means for monitoring current through said first electrode; means for providing substantially constant current to said first electrode, in said circuit means; and switching means, in said circuit means, for switching from said means for providing constant voltage to said means for providing constant current when said current monitored by said monitoring means reaches a predetermined value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An operable iontophoretic drug delivery system comprising:
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a drug reservoir adapted to be attached to the skin of an animal; a first electrode in said drug reservoir; an electrolyte reservoir adapted to be placed in communication with the skin of an animal; a second electrode in said electrolyte reservoir; circuit means for providing electrical communication between said first and second electrodes, said circuit means including means for connection to a source of electrical power; means for providing substantially constant voltage between said electrodes, in said circuit means, including at least one of means for monitoring current through said first electrode and means for monitoring voltage between the first and second electrodes; means for providing substantially constant current to said first electrode, in said circuit means; switching means, in said circuit means, for switching between said means for providing constant voltage and said means for providing constant current when at least one of the monitored current and monitored voltage equals a predetermined value; and power limiting means in said switching means for causing a transition from one constant voltage and constant current to a constant power provided to the first and second electrodes if a predetermined power, monitored by said power limiting means, is reached.
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11. An operable iontophoretic drug delivery system comprising:
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a drug reservoir adapted to be attached to the skin of an animal; a first electrode in said drug reservoir; an electrolyte reservoir adapted to be placed in communication with the skin of an animal; a second electrode in said electrolyte reservoir; circuit means for providing electrical communication between said first and second electrodes, said circuit means including means for connection to a source of electrical power; means for providing substantially constant voltage between said electrodes, in said circuit means, including at least one of means for monitoring current through said first electrode and means for monitoring voltage between the first and second electrodes; means for providing substantially constant current to said first electrode, in said circuit means; switching means, in said circuit means, for switching between said means for providing constant voltage and said means for providing constant current when at least one of the monitored current and monitored voltage equals a predetermined value; and power limiting means, in said switching means, for causing a transition from one constant voltage and constant current to a constant power provided to the first and second electrodes if a predetermined power is reached. - View Dependent Claims (13)
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12. The operable iontophoresis drug delivery system of claim further including means for measuring the current passing through said first electrode and for accumulating the total current passing through said first electrode.
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14. A circuit for connecting a pair of electrodes of an iontophoretic drug delivery system comprising:
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means for connecting said circuit to a source of power; means for providing substantially constant voltage between said electrodes; means for providing a substantially constant current to one of said electrodes; means for monitoring current through one of said electrodes; means for switching from said means for providing constant voltage to said means for supplying constant current when said current monitored by said monitoring means reaches a predetermined value.
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15. A circuit for connecting to a pair of electrodes of an iontophoretic drug delivery system comprising:
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means for connecting said circuit to a source of power; means for providing substantially constant voltage between said electrodes; means for providing a substantially constant current to one of said electrodes; at least one of means for monitoring current through one of said electrodes and means for monitoring voltage between the electrodes; means for switching between said means for providing constant voltage and said means for providing constant current when at least one of the monitored current and the monitored voltage equals a predetermined value; and power limiting means in said switching means for causing a transition from one of said constant voltage and constant current to a constant power provided to the electrodes if a predetermined power between said electrodes is reached.
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16. A method for iontophoretic drug delivery through the skin of an animal using an iontophoretic drug delivery device having an ionic compound containing reservoir, a first electrode in said ionic compound containing reservoir, an electrolyte containing reservoir, and a second electrode in said electrolyte containing reservoir comprising the steps of:
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(a) attaching said iontophoretic drug delivery device to the skin of an animal; (b) causing electrical power to flow between said electrodes at a constant predetermined voltage; (c) monitoring the current while said power is being delivered at constant voltage; (d) when said monitored current reaches a predetermined current causing the electrical power between said electrodes to change from constant voltage to constant current at said predetermined current; and (e) continuing to cause electrical power to flow between said electrodes at a constant predetermined current. - View Dependent Claims (17)
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18. A method for iontophoretic drug delivery through the skin of an animal using an iontophoretic drug delivery device having an ionic compound containing reservoir, a first electrode in said ionic compound containing reservoir, an electrolyte containing reservoir, and a second electrode in said electrolyte containing reservoir comprising the steps of:
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(a) attaching said iontophoretic drug delivery device to the skin of an animal; (b) causing electrical power to flow between said electrodes at at least one of a constant predetermined voltage and a constant predetermined current; (c) at least one of monitoring the current to one of the first and second electrodes while said power is being delivered at constant voltage and monitoring the voltage between the first and second electrodes while said power is being delivered at a constant current; (d) when at least one of the monitored current and monitored voltage equals a predetermined value, causing the electrical power between the first and second electrodes to change between a constant voltage and a constant current; (e) monitoring power between said electrodes; and (f) if the monitored power reaches a predetermined value, causing the power to the electrodes to change from one of constant voltage and constant current to a constant power provided to the electrodes.
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19. In combination:
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a drug delivery device attachable to a patient for supplying a drug to the patient by iontophoresis, the drug delivery device including a pair of electrodes; and an electronic circuit coupled to the electrodes of the drug delivery device and selectively providing at least one of a controlled voltage and a controlled current to the electrodes, the electronic circuit comprising; adjustable voltage and current generating means coupled to the electrodes of the drug delivery device and providing one of a selectively adjustable current and voltage to the electrodes; means for sensing the current provided to the electrodes of the drug delivery device, the current sensing means generating a sensed current feedback signal which is proportional to the sensed electrode current; means for sensing voltage provided to the electrodes of the drug delivery device, the voltage sensing means generating a sensed voltage feedback signal which is proportional to the sensed electrode voltage; means coupled to the current sensing means for comparing the sensed current feedback signal with a predetermined current threshold signal and generating a current state signal in response to the comparison thereof; feedback signal selector means, the feedback signal selector means being responsive to at least the current state signal and receiving at least the sensed current feedback signal and sensed voltage feedback signal and generating a feedback signal corresponding to at least one of the sensed current feedback signal and the sensed voltage feedback signal in response to at least the current state signal; setpoint selector means, the setpoint selector means receiving a preselected voltage limit signal and preselected desired drug delivery current signal and being responsive to at least the current state signal, the setpoint selector means generating a setpoint signal corresponding to at least one of the voltage limit signal and the desired delivery current signal in response to at least the current state signal; and means for subtracting the feedback signal from the setpoint signal, the subtracting means generating an error signal corresponding to the difference between the feedback signal and the setpoint signal; the voltage and current generating means being responsive to the error signal and adjusting at least one of the current and voltage provided to the electrodes in response thereto. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26)
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Specification