Invited Speaker

New Technologies to allow Transdermal Delivery of Biopharmaceuticals
Ajay Banga
USA

In recent years, there has been increasing interest in enhancement technologies that can expand the scope of transdermal delivery to biopharmaceuticals which are typically hydrophilic molecules and often macromolecules. These molecules do not normally pass through the skin unless enabling technologies are used. Some of the enabling technologies include iontophoresis, phonophoresis, or microporation. Recent innovations in these technologies, especially for iontophoresis and microporation, will be presented. Microporation involves the creation of micron-sized micropores or microchannels in the skin which can then allow the transport of water soluble molecules. Skin microporation can be achieved by microneedles or by using thermal, laser, or radio-frequency ablation. We have used soluble microneedles made of maltose as well as metal microneedles to demonstrate delivery of human growth hormone and larger proteins like antibodies or even micron sized particulates. Iontophoresis involves the application of small amounts of physiologically acceptable currents to drive ionic drugs into the skin. We have demonstrated iontophoretic delivery of several drug molecules including peptides such as calcitonin. We have also used a combination of iontophoresis and microneedles to show that charged drug molecules can be propelled via microchannels created in the skin by microneedles to achieve delivery flux higher than that could be achieved by either technique alone.