The influence of iontophoresis on acyclovir transport and accumulation in rabbit ear skin.
OBJECTIVE
The aim of this work was to explore the effect of iontophoresis on acyclovir (ACV) accumulation and permeation. In particular, the objectives were to check the efficacy of the transport mechanisms, electromigration and electrosmosis, on drug accumulation.


METHODS
Permeation experiments were performed in vitro, using rabbit ear skin as barrier, from donor solutions at pH 3.0, 5.8, and 7.4. At the end of the experiments, drug accumulation in epidermis and dermis was measured. Anodal and cathodal iontophoresis were applied at pH 3.0, whereas only anodal iontophoresis was used at pH 5.8 (current densities 0.06--0.50 mA/cm(2)) and 7.4.


RESULTS
Cathodal iontophoresis was more efficient than anodal iontophoresis on ACV permeation across the skin at pH 3.0. At pH 5.8, ACV flux and accumulation increased with current density during anodal iontophoresis. At pH 7.4, anodal iontophoresis produced a remarkable increase of flux and a modest increase of accumulation. Overall, anodal flux increased as the pH of the donor solution was increased as a result of the increase of the skin net negative charge.


CONCLUSIONS
From the results obtained in the present work, it can be concluded that iontophoresis application increases ACV flux and, to a limited extent, accumulation in the skin.
Padula
Cristina
C
Dipartimento Farmaceutico, University of Parma, Parco Area delle Scienze, 43100 Parma, Italy.
Sartori
Francesca
F
Marra
Fabio
F
Santi
Patrizia
P
D000212:Acyclovir / Q000493:pharmacokinetics*; D000818:Animals; D000998:Antiviral Agents / Q000493:pharmacokinetics*; D004423:Ear; D006863:Hydrogen-Ion Concentration; D007478:Iontophoresis; D011817:Rabbits; D012867:Skin / Q000378:metabolism*
D000998:Antiviral Agents; D000212:Acyclovir