Iontophoretic drug delivery system and method for using same

摘要

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.