Significant breakthroughs in transdermal delivery of drugs have occurred in
recent years owing to new technology and strategies used for transporting drug across
the skin. Transdermal drug delivery systems (TDDS) provide many benefits, such as
the avoidance of hepatic clearance, ease of application, better patient acceptance, and
regulated release of medication; yet, patients and physicians still face numerous
challenges. Due to the skin's excellent barrier function and lipophilic nature, one of the
main obstacles for TDDS is the restricted amount of drug placement, specifically for
drugs with molecular weights > 500 Da. Many pharmacological molecules, including
high molecular weight pharmaceuticals, have been the subject of much research,
especially in relation to biotechnologically manufactured medications delivered using
TDDS. This chapter covers the principles of transdermal drug delivery systems,
including their types, components, evaluation, lab and large-scale manufacture. This
chapter also emphasizes on new technologies that have improved skin permeability and
the regulatory considerations for transdermal formulation.
Keywords: Drug delivery, Film formulations, Flux, Lab scale and large-scale production of transdermal patches, Penetration, Permeation coefficient, Skin as port of drug delivery, TDDS, Transdermal patch.