The present study investigates how effectively
lidocaine ions are transported across a cellophane
membrane through the application of either a
direct current (DC) or alternating current (AC).
The cellophane membrane was set on a parallelplate-
type acrylic cell with platinum electrodes at
both ends, filled with a donor cell of a 1 % aqueous
solution of lidocaine and a receptor cell with distilled
water. Lidocaine concentrations were measured for
60 min while the following voltages were applied,
with changes every 10 min: 3 V DC and 7.5 V sine
wave AC; frequency at 1 kHz. As a result, lidocaine
concentrations in the receptor cell increased in a
time-dependent manner. Significant increases in
lidocaine concentrations were observed in groups
where the voltage combination consisted of DC
30 min/AC 30 min, DC 50 min/AC 10 min, DC 60
min and AC 10 min/DC 50 min, compared with the
passive diffusion group or in groups where voltage
application was performed for 20, 30 , 40, 50 and
60 min. Significant increases were also observed
in groups where the voltage combination consisted
of A C 6 0 min, D C 10 min/AC 5 0 min, AC 3 0 min/
DC 30 min and AC 50 min/DC 10 min, compared
with the passive diffusion group or in groups where
voltage application was performed for 40, 50 and
60 min. These results suggest that lidocaine was
delivered more rapidly with DC than with AC, and
that its ions are transported faster when voltage
is switched from DC to AC than from AC to DC,
which is presumably due to the contribution of
electrorepulsion by DC voltage application and the
vibration energy infiltration mechanism owning to
AC. Iontophoresis in combination with DC and AC
was found to enable highly efficient drug delivery
that shares the benefits of both forms of current
application.
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