Iontophoresis: A Physical Approach to Transdermal Drug Delivery System

In the last three decades, many advances have been made in the field of drug delivery, with resulting enhancements in the safety, efficacy and convenience of treatment for the patient. Some of the more dramatic developments include technologies that allow for the noninvasive transdermal delivery of several drugs. This delivery is accomplished by Iontophoresis, a process by which an electrical current is used to drive charged particles across the skin and is acts as a one of the most promising physical skin penetration enhancing method. In Iontophoresis, the application of constant electrical current enhances the transdermal transport of a charged drug molecule due to electro-repulsion. The electric field imposes a force on the drug molecule, which adds to the pure passive diffusion or the concentration gradient. During Iontophoresis, the skin permeability also increases due to changes in the structure of the skin caused by current flow. This review briefly describes the advantages, limitations of Iontophoretic drug delivery system and summarizes the experimental design along with electodes used for iontophoretic drug delivery system. Present review also provides an insight on iontophoretic electrochemistry. Various parameters which affect the transdermal absorption of drugs through iontophoresis like electrical, physicochemical and operational have also been reviewed in detail.