Transdermal Lidocaine Iontophoresis in Isolated Perfused Porcine Skin

Abstract

The isolated perfused porcine skin flap (IPPSF) is an alternative animal model for quantitatively assessing percutaneous drug absorption. The ability to place drugs or chemicals on the surface of viable skin with a functional microcirculation maintained in a controlled ambient environment, coupled with the measurement of arterial and venous drug concentrations, makes this model well suited for modeling percutaneous drug flux after transder-mal delivery. Lidocaine hydrochloride was used as the model drug to investigate the dynamics of transdermal delivery using iontophoresis. Total lidocaine flux (bioavailability) was a function of lidocaine concentration, current density, and duration of application. Rate of transdermal flux was a function of concentration, current density, and the presence or absence of coadministered epinephrine (reduced) or tolazoline (increased). The presence of vasodilators significantly affected the magnitude of peak venous