Iontophoretic Transdermal Drug Delivery

Abstract

This chapter details the concepts, principles, and applications of iontophoresis and explores its current standing and potential in the increasingly growing transdermal drug delivery segment. Transdermal drug delivery systems (TDDS) constitute patches that deliver low-molecular-weight molecules such as fentanyl, clonidine, nicotine, scopolamine, and various hormones such as testosterone, estradiol, and the birth control combinations of norelgestromin/ethinyl estradiol. Various penetration enhancement techniques have been investigated over the years to extend the application of transdermal delivery to agents that target other therapeutic areas. These techniques, broadly classified as chemical and physical enhancement techniques, are reversible methods that alter the skin barrier to increase the permeation of compounds through the skin and achieve therapeutically effective concentrations in the underlying tissues. Fentanyl iontophoretic transdermal system, Hybresis iontophoresis drug delivery system, and gluco watch G2 biographer for monitoring of glucose are some iontophoretic devices that are commercially available or nearing commercialization. Iontophoresis has also demonstrated great value for the delivery of macromolecules such as proteins and peptides, as it enhances their transdermal permeation while protecting them from the harsh proteolytic environments encountered with oral delivery. In addition to transdermal delivery, iontophoresis has shown great potential in other fields and is being increasingly researched for its application in the treatment of hyperhidrosis, ocular drug delivery, and for delivery through the nail for the treatment of fungal nail infections