Iontophoretic drug delivery system and method for using same

• US 5,540,669 A
• Filed: 12/01/1995
• Issued: 07/30/1996
• Est. Priority Date: 09/30/1993
• Status: Expired due to Term

• Current Assignee: Vyteris, Inc.
• Original Assignee: Becton, Dickinson & Co
• Inventors: Sage, Burton H. Jr., Flower, Ronald J.
• Primary Examiner(s): Yasko, John D.
• Assistant Examiner(s): Bockelman, Mark
• Application Number:
  US08/566,318
• Time in Patent Office: 242 Days
• Field of Search: 604/20, 604/290, 607/149-152
• US Class Current: 604/290
• CPC Class Codes: A61N 1/044 Shape of the electrode
• CPC Class Codes: A61N 1/0448 Drug reservoir
• 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

An iontophoretic drug delivery device of the present invention includes a power source and an electrode assembly in electrical contact with at least three reservoirs, with at least two of the reservoirs containing an active formulation to be delivered to an applied area of a patient, with a switch for switching the flow of current from between the first electrode and the third electrode and between the second electrode and the first electrode so as to reduce sensation. The device also includes a timer for controlling the amount of time the electrical current flows between a pair of electrodes. In the preferred embodiment, the active formulation includes a local anesthetic such as Lidocaine and a vasoconstrictor such as Epinephrine. In this way, the device is suitable for use to deliver the local anesthetic to the applied area approximate the first reservoir for a first period of time and to deliver the local anesthetic to the applied area approximate the second reservoir during a second period of time. Thus, switching between pairs of electrodes and iontophoresing thereunder below the sensation threshold results in sensation anesthesia so that the current can be raised to deliver the drug without sensation.

Claims

1. A method of reducing sensation during rapid iontophoretic delivery of at least a local anesthetic to an applied area of a patient such as the skin, mucous membrane or the like, comprising the steps of:

applying a first portion of an iontophoretic drug delivery device including an electrode assembly having a first electrode and a first reservoir containing the local anesthetic to be delivered to the applied area of the patient;

applying a second portion of the device including said electrode assembly having a second electrode and a second reservoir containing said local anesthetic to be delivered to the applied area of the patient;

applying a third portion of the device including said electrode assembly having a third electrode and a third reservoir;

generating an electrical current between said first electrode and said third electrode through the applied area of the patient during a first period of time at low current so that at least enough of said local anesthetic is delivered to the applied area of the patient approximate said first electrode and said first reservoir during said first period of time to anesthetize the applied area approximate said first electrode and said first reservoir at least sufficiently to avoid sensation due electrical current flowing through the applied area of the patient approximate thereto; and

generating an electrical current between said first electrode and said second electrode through the applied area of the patient during a second period of time so that during said second period of time a higher current is provided for a longer period of time to said second electrode to deliver said local anesthetic to anesthetize the applied area of the patient approximate said second electrode and said second reservoir without unwanted sensation due to electrical current flowing through the applied area of the patient and to minimize sensation from the subsequent insertion of a needle or the like into the applied area of the patient.

2. A method of reducing sensation as defined in claim 1, wherein a vasoconstrictor is delivered along with said local anesthetic.

3. A method of reducing sensation as defined in claim 2, wherein said local anesthetic is Lidocaine and said vasoconstrictor is Epinephrine.

4. A method of reducing sensation as defined in claim 1, further comprising the step of varying the amount of electrical current.

5. A method of reducing sensation as defined in claim 1, wherein said step of generating an electrical current during said first period of time includes limiting the amount of electrical current delivered to at least initially less than or equal to 0.5 mA.

6. A method of reducing sensation as defined in claim 5, wherein said step of generating electrical current during said second period of time includes limiting the amount of electrical current delivered to at least initially less than or equal to 0.5 mA.

7. A method of reducing sensation as defined in claim 6, further comprising the step of generating an electrical current between said first electrode and said second electrode for at least one additional period of time during which the amount of electrical current delivered is greater than 0.5 mA.

8. A method of reducing sensation as defined in claim 7, wherein the amount of electrical current delivered during said at least one additional period of time is in the range of approximately 0.05 mA to 1.5 mA.