Lidocaine transport through living rat skin using alternating current

The purpose of the study was to determine whether lidocaine could be transported through living rat skin using alternating current and to determine whether lidocaine transport depends on voltage. The drug delivery cell was originally constructed for the application of an electric field. Hairless rats were anaesthetised using sevoflurane, and a tracheotomy was performed. The drug delivery cell, with lidocaine solution in the donor cell, was placed on the abdominal skin. Samples were collected from the subcutaneous tissue using a microdialysis probe inserted into the abdominal subcutaneous tissue, and the lidocaine concentrations in the samples were determined using high-performance liquid chromatography. The lidocaine concentration in the rat skin increased in time, and voltage-dependency was approximately linear. The lidocaine concentration after the application of 20 V for 21 min was about ten-fold higher than that observed after 21 min of passive diffusion. Lidocaine was successfully transported through living rat skin in a voltage- and time-dependent manner. This drug delivery cell may contribute to local anaesthesia and pain management of human skin.