Bio-feedback iontophoresis patch for controllable transdermal drug delivery

The bio-feedback iontophoresis patch is proposed for controllable transdermal drug delivery. The proposed iontophoresis patch is implemented with the bio-feedback iontophoresis integrated circuit (IC) on the planar-fashionable circuit board (P-FCB) technology. For controllable iontophoresis treatment, the bio-feedback iontophoresis IC provides programmable stimulation current (16-512μA amplitude, DC-500Hz frequency, and 3-100% duty cycle) and monitors the dual-mode (load and tissue) impedance and the skin temperature during iontophoresis treatment with the reconfigurable tetra-polar electrode configuration. The load impedance is used to determine the stimulation current level, which means the instantaneous delivered dosage, for optimized iontophoresis treatment. The measured tissue impedance is used as an indicator of the accumulated delivered dosage. The skin temperature sensor prevents the unexpected side effects, such as skin burn or tissue destruction. As a result, the proposed iontophoresis patch monitors drug delivery status and patient's status. The proposed iontophoresis system is fully implemented and verified on both in-vitro and in-vivo tests.