Transdermal Drug Therapy: Emerging Techniques and Improved Patient Compliance

Abstract

Transdermal drug therapy has made a breakthrough over the past few years amid emerging technologies and strategies for repositioning of drugs to deliver through the skin: a strong barrier. In spite of various benefits of transdermal routes of drug delivery such as avoidance of first-pass metabolism, easy mode of application, high patient compliance, and controlled release of medication, researchers today are facing numerous challenges in order for patients and clinicians to embrace transdermal drug delivery system (TDDS). One of the key impediments facing TDDS is the narrow range of drug positioning as a result of the skin being a strong barrier for drugs with molecular weight > 500 Da and its hydrophilic nature. To overcome these challenges, immense research work was carried out to extend the scope of TDDS to incorporate wide range of drug molecules which may include high molecular weight drugs, especially biotechnologically developed macromolecules and vaccines. Moreover, extensive research was undertaken by scientists in developing new transdermal technologies to deliver wide range of drugs to treat various chronic diseases. The quantum of research work is demonstrated by many patents filed and granted to industries and academic institutions. This chapter discusses about the basics of transdermal permeation mechanisms considering physiochemical characteristics of drug molecules and drug delivery systems. Furthermore, it focuses on emerging technologies for skin permeation enhancement that has led to high patient compliance. Besides, it also illustrates on the current available TDDS in the market with narrow range of drugs; however, ongoing clinical trials and new technologies suggest that there is a great future of TDDS in repositioning wider range of drugs bypassing the existing patents.