Noninvasive transdermal delivery of peptides and proteins

Revolutionary advances in biotechnology have given rise to a large number of drugs that are of peptide and protein origin. In order to reap the ultimate therapeutic benefits of these new generation drugs, there is both a commercial and clinical need to develop suitable noninvasive delivery systems. Over the last several decades, the skin has generated a lot of interest as a site for systemic delivery of drugs. However, in order to expand the scope of drugs that can be delivered transdermally, a number of competitive enhancement technologies are under investigation. Iontophoresis using a small electric current offers immense potential for small peptides, while electroporation and sonophoresis can be useful for large peptides. Very large proteins may be delivered by combination of enhancement techniques. Other approaches such as transferosomes and high speed powdered delivery can also be useful for certain therapeutic categories. This article reviews the potential of various strategies for transdermal delivery of peptides and proteins with special emphasis on mechanism of transport and delivery system considerations.