The growth in the biologics market has given the industry an extra incentive to find painless ways of administering vaccines.
Recent animal studies indicate that the transdermal route could be a viable option.
Researchers from the Georgia Institute of Technology vaccinated mice against influenza using patches that contained dissolving
microneedles. This administration method provided at least as much protection as traditional hypodermic injections, according
to their July 2010 article in Nature Medicine.
A $10-million grant from the National Institutes of Health will enable the researchers, in cooperation with Emory University,
to develop the patch further and conduct a Phase I clinical trial. The patch uses a dry form of the vaccine, and the team
will study its stability to determine whether it can be stored without refrigeration.
Another goal of the study is to ensure that the patch is simple and reliable enough for any patient to use without assistance,
says Mark Prausnitz, the project's principal investigator. If the study is successful, the patch eventually could become a
more popular delivery device than autoinjectors.
Until recently, transdermal delivery had been restricted to small and lipophilic molecules. Projects such as Prausnitz's open
the possibility that vaccines and other large-molecule drugs could be given effectively through the skin. Such easy and painless
administration could have big benefits for public health. For needlephobes and drug-delivery scientists alike, the prospects
Erik Greb is an associate editor of Pharmaceutical Technology.