ABSTRACT
This chapter aims to summarize advances in transdermal and topical drug delivery systems. Transdermal delivery has enjoyed significant innovations with respect to physical enhancement technologies such as iontophoresis, electroporation, sonophoresis, jet propelled particles and microporation, expanding its horizon to the delivery of biotherapeutic macromolecules and water soluble molecules. The chapter focuses on the most promising technologies, including iontophoresis, sonophoresis microporation and microneedles. Microneedle-based products have found their way in the commercial realm. Skin recovery following use of microneedles has been a subject of research as it is a determinant of safety and it is important from a regulatory perspective to show that creation of micropores in the skin does not pose safety/infection risks. The sonophoretic enhanced microneedle array technology greatly enhances delivery rates by employing hollow microneedles in conjunction with a sonophoretic emitter. Physical enhancement techniques such as iontophoresis, microporation, sonophoresis and microneedles have expanded the scope of transdermal delivery to hydrophilic molecules as well as macromolecules.