Enhanced transdermal delivery of tetracaine by electroporation

The effect of electroporation on the transport of tetracaine through skin in vitro was studied using side-by-side compartment diffusion cells method. After achieving steady state by passive diffusion, fluxes of tetracaine achieved with passive diffusion, electroporative pulse and iontophoresis were compared. Electroporation (square-wave pulse, voltage 130 V, pulse time 0.4 s, pulse frequency 40 pulses min −1) or iontophoresis (0.2 · mA cm −2, lasting for 4 h) increased the transport of tetracaine through skin. The flux of tetracaine at 0.25 h after electroporation (pulse number 400) was 54.6±6.0 μg · cm −2 · h −1, that after iontophoresis was 17.4±5.8 μg · cm −2 · h −1 and that after passive diffusion was 8.2±0.5 μg · cm −2 · h −1. In addition, the fluxes of tetracaine increased with the increasing of pulse number. From these results, it is clear that electroporation is effective in enhancing transdermal delivery of tetracaine and its function is better than iontophoresis.