Abstract
The dissolving microneedles（MN） made of water-soluble polymers and coating MN made of biodegradable polymers were developed, and the world’s first skin care cosmetics applying hyaluronic acid MN technology was commercialized in 2008. In the medical field, MN formulations were developed for the transdermal delivery of protein/peptides such as exendin-4（anti-diabetic drug） etc., and their kinetic behaviors were almost equivalent to subcutaneous injection. The MN is a promising vaccine administration method that minimizes pain, allows for minimally invasive and self-administration, and enables large-scale and rapid vaccination during pandemic emergencies. The clinical studies using influenza vaccine MN have shown that it is safe and effective against type A and type B strains according to the European Medicines Agency（EMA） criteria. The immune response to A/H1N1 and A/H3N2 strains induced by MN administration was almost equivalent to that by subcutaneous injection, and the immune response to B/Brisbane strain was higher than that by subcutaneous injection. In particular, we have developed DonutNeedlesⓇ, which has significantly improved skin puncture properties, and are making progress toward the development of novel vaccine.
