There is much to look forward to for both passive and active transdermal drug delivery systems. "There is a huge opportunity
for active diffusion as many products currently on the market are very difficult to deliver through passive diffusion. However,
the passive diffusion market has certainly not been exhausted," says Myers. "Critical to the success of active diffusion is
to develop products that are cost effective to the consumer."
Cirrus is exploring the use of nanotechnology in various areas of drug delivery and is capable of extending the technology
to TDDS to improve skin permeation. Scientists at Adhesives Research are working on the development of a porous adhesive platform
with tailorable pore sizes and densities that create pathways through which a drug may flow to the skin or moisture and other
materials may be removed from the surface of the skin. The company also is developing coatings with molecularly imprinted
polymers (MIPs). "These MIPs are synthesized with the unique chemical and physical 'imprint' of a target molecule. MIPs
can be formulated into an adhesive coating and used to capture or release the target molecule in a diagnostic or drug delivery
application," says Knorr.
"Where I see the technology going and where I see the market hasn't really expanded is partnerships with a pharmaceutical
company to preload the devices with the drugs," says Duncan.
"We are at the forefront of what we can do," adds Pomonis. "We are clearly able to, with advances in microprocessors and electronics
and circuitry, come up with very complex dosing regiments. We are understanding more and more about skin resistance and how
that affects drug delivery. There are drugs sitting in the chemical libraries of pharmaceutical companies that have not made
it through the development process either because of challenges in formulation or more likely worries about systemic side
effects that may be addressed with advanced transdermal systems. Truly there should be a tremendous opportunity in the near
future for those collaborations."