Transdermal science and technology-an update

Abstract

Transdermal drug delivery represents a validated technology which is contributing significantly to global pharmaceutical care. Over the last 40 years, impressive growth in this field has been observed with many commercial successes;indeed, very recently, a new chemical entity has been developed and approved for transdermal administration without first passing via an injectable or oral dosage form. The progress achieved has been catalyzed by the clearer understanding of skin barrier function, and of the physicochemical, pharmacokinetic and physiological factors which determine the feasibility of transdermal administration. Research into novel, non-invasive approaches to facilitate and control drug transport across the skin is intensive, with certain technologies, such as iontophoresis, now achieving true maturity. Advances in the field have also allowed the "local", subcutaneous delivery of drugs (for example, to underlying muscle and other tissues) to be improved and the opening of new markets in this lucrative area may be envisaged.