The aim of this study was to investigate whether transdermal delivery
of domperidone can be enhanced to therapeutic levels by iontophoresis
and/or electroporation. In vitro studies were performed with a solutio
n of domperidone pH 3.5 in 9.5% (v/v) ethanol. Iontophoresis (2 h at 0
.4 mA/cm(2)) increased the transdermal permeation by a factor 15 as co
mpared to passive diffusion. Application of 5 long (tau = 700 ms) high
-voltage (250 V) pulses increased the domperidone permeation by a fact
or of up to 70. Application of one pulse (250 V-700 ms) prior to ionto
phoresis provided similar penetration enhancement to 5 pulses (250 V-7
00 ms). No significant enhancement was provided by application of one
short pulse (1000 V-4 ms) prior to iontophoresis, probably due to a di
fferent mechanism of permeabilization and/or recovery kinetics to the
initial permeability state. The domperidone permeation flux by skin el
ectroporation (1.5 mu g/cm(2) h) is in the range of the fluxes measure
d with chemical penetration enhancers but the lag time was reduced. Ho
wever, due to the low hydrosolubility of domperidone, electrically enh
anced flux remains too low for therapeutic application. (C) 1997 Elsev
ier Science B.V.