PPT Slide
Methods of Transdermal Drug Delivery
Flux of ions across skin is increased with an electric field.
Two mechanisms are responsible for the increased flux:
(1) Iontophoresis, in which a charged ion moves away from the
electrode of like charge.
(2) Electroosmosis, the convective movement of solvent that occurs
through a charged pore in response to the preferential passage of
• Skin isoelectric point is 4, so under physiological conditions
the SC has a net negative charge.
• Electroosmosis therefore occurs from anode to cathode.