(190c) Transdermal Protein Delivery and Immunization Using Nano-Coating Drug Carrier

In the present study, we demonstrated that a solid-in-oil (S/O) nanodispersion, an oil-based nanodispersion of hydrophilic drugs, effectively enhanced the permeation and immunization of proteins through the skin. Two different model proteins, FITC-labeled insulin and HRP, permeated through the stratum corneum (SC) of Yucatan micropig skin in vitro by forming the S/O nanocarrier. The penetrated HRP exhibited catalytic activity, suggesting that the proteins can permeate into the skin in a functional form. It has been difficult to achieve therapeutic levels of relatively large drugs (over 500 Da) through intact skin to the systemic circulation by the chemical penetration enhancer alone. To overcome these situations, a surface nano-coating technique is proposed. In my presentation, the surfactant–protein complexes in which proteins are coated with hydrophobic surfactant molecules are prepared. The modified proteins can be highly dispersed in an oil of interest. The idea is that the dispersion of the surfactant–protein complex in the oil phase as a nano-order particle makes the proteins permeable into the skin. This concept is novel because to date, almost all studies on transdermal delivery of hydrophilic drugs have been based on aqueous vehicles. The results obtained in this study clearly suggest that the S/O nanodispersion technique has a high potential for the creation of a novel protein immunization system.