A team of investigators from North Carolina State University and the University of North Carolina at Chapel Hill have designed a novel drug release technology that relies on a stretchable elastomer and drug loaded nanoparticles to unload medication when the skin flexes and contracts. The idea is that this kind of approach can deliver drugs transdermally only when needed. For example, people with arthritis may be able to get pain relieving drugs during walks in doses that are proportional to how many steps are taken.
The patches consist of an elastomer that has tiny capsules throughout its surface, each filled with drug loaded nanoparticles. The nanoparticles are designed to slowly release a medication into the capsules where they reside. The capsules themselves are not impermeable, but will let compounds through when enough pressure is applied to them. This pressure comes from stretching of the elastomer film, which in turn stretches the capsules and compresses them to release the drugs. Microneedles placed below each capsule allow the drugs to pass into the skin. The combination of the mechanisms lets the nanoparticles load the capsules with a small amount of a medication and release it into the skin immediately on demand.