Topical and transdermal drug delivery systems (TDDs) have several advantages over traditional drug delivery methods, as they can be less invasive, more sanitary, more cost-effective, and may result in better patient compliance. TDDs play a significant role in therapeutics with a variety of preparations and approaches designed by expert formulation scientists. This volume integrates a wide variety of case studies, research, and theories to reveal their diversity and capture the novel approaches of transdermal and topical drug delivery employed by developers and content experts in the field. It provides an abundance of important information and state-of-the-art research on topical and transdermal drug delivery systems and addresses the basics of drug delivery systems, strategies to enhance permeation across membranes, and formulation and evaluation of diverse dosage forms. The volume presents an evaluation of the pros and cons of conventional drug delivery systems against TDDs and discusses the nuances of micro- and nano-systems in TDDs. The extraordinary packages of nano systems (vesicular systems, polymeric nanoparticles, nanoemulsion and dendrimers) are broadly discussed, and their applications are reviewed through a transdermal route. The book looks at TDDs and the main nanoparticles used in skin diseases and lesions of the aging, such as psoriasis, vitiligo, cancer, lesions of the aging and others. Chapters also discuss polymeric micelles in topical and transdermal delivery; microneedles; emulsion, nanoemulsion and microemulsion; TDDs in pulmonary drug delivery systems; nanoencapsulated nasal drug delivery systems; skin sensitivity and irritation testing for transposing transdermal drug delivery systems; and regulatory aspects of drug development for dermal products. Topical and Transdermal Drug Delivery Systems: Applications and Prospects will be a valuable resource for pharmaceutical scientists and researchers, industry professionals, and academicians and students of the pharmaceutical and biomedical sciences.