Transdermal Drug Delivery by Electroporation: The Effects of Surfactants on Pathway Lifetime and Drug Transport
Abstract Electroporation creates aqueous pathways by short high voltage pulses resulting in a transient perme abilization of stratum corneum and an increase in the transdermal delivery rate. However the aqueous pathways will reseal after pulsing, which leads to the rapid drop of transdermal flux. In the present study, the surfactants were added to the donor solution to hinder the shrinkage and resealing of the electropore, and to prolong the lifetime of the aqueous pathways with the consideration that the surfactants could reduce the surface energy of the electropore. These effects of surfactants were demonstrated by the dynamic electrical resistance of the skin and the fluorescent imaging of the local transport regions. Piroxicam (PIX) was transported percutaneously in the presence of surfactants in vitro. Owing to the longer lifetime of aqueous pathways, together with the promotion of PIX availability at the barrier exterior and the improvement in the partition of PIX into the aqueous pathways, the presence of surfactants led to a remarkable increase in the transdermal delivery rate during electroporation and a significant growth of the accumulative transdermal amount of PIX.