ABSTRACT
Iontophoresis is the use of a direct electrical current to drive topically applied ionized substances into or through a tissue (1). Iontophoresis is based on the physical principle that ions with the same charge repel (electrorepulsion) and ions with opposite charge attract (electroosmosis) (2). Iontophoresis usually employs low voltage (10 V or less) to supply a continuous direct current of 0.5 mA/cm2 or less (1). These basic operational guidelines have enabled iontophoresis to be used to enhance drug delivery in a wide variety of conditions. The symmetry of the procedure also permits its application to the noninvasive sampling of biologically important subcutaneous fluids or for blood monitoring (3). Table 1 lists reviews on the topic and selected citations that highlight some of the innovative ways in which this modality is being used in the treatment and diagnosis of various conditions.
