Microneedles and transdermal drug delivery

Transdermal delivery has become a popular route of drug delivery in recent years. However, permeation of drugs through skin is limited to small lipophilic molecules. Microneedle technology involves the creation of micron-sized channels in the skin, which can allow the delivery of hydrophilic molecules including large proteins which do not pass the skin barrier passively. Microneedles can be manufactured in different geometries from various materials such as silicon, glass, sugars and polymers and this technology has been shown to effectively increase the permeation rates of a wide range of therapeutic compounds, including proteins, in several studies on animal models and humans. Combination with other techniques such as iontophoresis and sonophoresis may result in synergistic effects. New products involving microneedle technology are currently being developed in the industry and the prospects are highly promising.