Transdermal drug delivery systems for psychological disorders

The rapid growth in the number of patients with psychological disorders puts immense pressure on the economy, society, and healthcare systems. Various classes of drugs have been approved for different psychological disorders; however, a vast number of these medicines experience first-pass metabolism and low bioavailability, plasma level fluctuations, side effects, and the need for frequent daily doses, which all lead to poor patient compliance. Besides, the mental condition of these patients makes it hard for them to use drugs in oral dosage forms, frequently. Transdermal delivery systems have drawn attention to the treatment of different psychological disorders, including psychosis, depression, anxiety, attention-deficit hyperactivity disorder (ADHD), and sleep disorders. These systems offer a substitute route to address mentioned issues and improve patient adherence, particularly in long-term administration. Different devices have been designed to facilitate the administration of drugs through transdermal routes, such as patches and microneedles. Moreover, to enhance the absorption of medicines, chemical penetration enhancers, iontophoresis, radiofrequency, and nanotechnology are integrated with these transdermal delivery systems, which is the basis of the development of generations of transdermal delivery systems. In this review, we will focus on more novel generations of transdermal delivery systems and their applications for psychological disorders.