ABSTRACT
This chapter examines strategies that reportedly, physically or mechanically perturb or circumvent the stratum corneum barrier, such as microneedles, laser ablation, electroporation, or physically enhanced flux, such as iontophoresis. It covers the majority of approaches that have been, researched and are not covered elsewhere. Transdermal delivery is achieved by firing the liquid or solid at supersonic speeds through the outer layers of the skin using a suitable energy source, such as a helium gas cylinder. Encapsulation of drugs and cosmetics into vesicular systems has been popular for numerous delivery routes, and many topical preparations utilise the technology. Although topical liposomal drug formulations have not been hugely successful in commercial terms, the literature contains numerous research papers on use of liposomes to deliver many diverse therapeutic agents to, and across, various membranes. Microneedles can puncture the skin to create micron-sized channels and can be used to facilitate both topical and transdermal delivery of molecules with diverse physicochemical properties across the skin.
