Transdermal drug delivery is a promising way to deliver active ingredients through the skin. Unfortunately, drug developers face considerable challenges when designing therapeutics that are able to pass through the tough outer layer of the skin, known as the stratum corneum.
While the stratum corneum protects the lower levels of skin cells from infection, it also prevents most drugs applied topically from passively diffusing into the blood stream. Now, researchers from Shizuoka University in Japan have developed a method using atmospheric microplasma to disrupt this impermeable layer, making the skin “leaky”.
Using conductive and non-conductive materials, the researchers tested the effects of the plasma treatment on the stratum corneum of pig skin. When the researchers used a conductive material, the plasma jet caused significant damage to the skin samples. Conversely, the non-conductive material using atmospheric microplasma caused no damage to the skin.
This non-conductive microplasma treatment also increased the permeability of the skin, as demonstrated using a dye test. While skin is normally impermeable to dyes, the microplasma treatment allowed the dye to enter the skin through the stratum corneum, suggesting that the same results could be seen with drug products.