Elastic vesicles as a tool for dermal and transdermal delivery.

The main problem in delivery of drugs across the skin is the barrier function of the skin, which is located in the outermost layer of the skin, the stratum corneum. The stratum corneum consists of corneocytes surrounded by lipid layers, the so-called lipid lamellae. When applying drugs onto the skin, the major penetration pathway is the tortuous intercellular route along the lipid lamellae. In order to increase the number of drugs administered via the transdermal route, novel drug delivery systems have to be designed. Among these systems are iontophoresis, electroporation, microneedles, and vesicular systems.