Affiliations: Ben-Gurion University of the Negev, The Institutes for
Applied Research, Beer-Sheva, ISRAEL
Note: [] Address for correspondence: Dr. Amnon Sintov Ben-Gurion
University of the Negev, The Institutes for Applied Research, P.O. Box 653,
Beer-Sheva 84105 ISRAEL Phone: +972 (7) 647 2709; Fax: +972 (7) 647 2960;
e-mail: asintov@bgumail.bgu.ac.il
Abstract: Percutaneous drug penetration studies were performed, during which
skin properties were altered. The present research characterizes, in
particular, the in vitro permeation kinetics of a 5% acyclovir cream through
hairless mouse skin. Cumulative amounts of penetrated acyclovir per 1 cm2 area
were monitored in a Franz diffusion cell system. Statistical models were
constructed to interpolate the experimental data obtained from 11 sets of
experiments (each, n = 6). The in vitro penetration of acyclovir through
hairless mouse skin over a 24-h period was found to be non-linear, with a slow
"early phase" up to 12 hours, followed by a rapid "late phase" (approximately
10 times faster). The histological finding of epidermal necrosis in the latter
periodbut not in the first 12 hoursprobably explains the
non-linear elevation of the drug transport rate in the diffusion study. The
data presented in this paper demonstrate a phenomenon, involving slow
deterioration of skin tissue, which complicates the prediction of the diffusive
behavior of drug-vehicle compositions penetrating through excised skin
in-vitro.top
Keywords: Percutaneous penetration, acyclovir, hairless mice, drug absorption, skin permeation