The objective of transdermal delivery system is to achieve optimum therapeutic management. But, it still remains a challenge in the field of pharmaceuticals for delivery of ionic species such as proteins and peptides. Development of iontophoretic system is a breakthrough in this field designed to improve the delivery rate of ionic compounds. This technique generates an electrical potential gradient that facilitates the movement of solute ions across the membrane. Iontophoresis is the process of increasing the penetration of drugs into the skin by application of an electric current. The drug is applied under an electrode of the same charge as the drug, and a return electrode opposite in charge to the drug is placed at a neutral site on the body surface. Electrical energy assists the movement of ions across the skin using the principle "like charges repel each other and opposite charges attract." Iontophoresis seems to be an ideal candidate to sort out the limitations associated with the delivery of ionic drugs. In this book, efforts have been made to summarize all the aspects of iontophoretic delivery.