چکیده (انگلیسی):

This study investigated the enhancement
effect of gramicidin, a cationic ionophore, on
percutaneous absorption of a model drug, benzoic acid
(BA), through rat abdominal skin. The mechanisms by
which gramicidin increased skin permeability to BA were
also investigated. Degree of hydration measured by the
Karl Fisher method, the concentration gradient measured
by cryostat analysis, and lipid concentration measured by
the Fiske-Subbarow method were evaluated and
compared. The results showed that BA permeation
profiles through rat abdominal skin followed dose- and
volume-dependent patterns. The pretreatment of
gramicidin increased the permeation rate of BA through
rat abdominal skin compared with the untreated control
(18.89 vs. 10.86 m g/cm2/hour). Change in skin
permeation rate of BA after gramicidin pretreatment was
closely correlated with the remaining skin water content.
There were no significant differences in the amounts of
phospholipid phosphorous between gramicidin pretreated
and untreated skin. The enhancing effect of gramicidin on
percutaneous absorption of a model drug is mainly
attributed to increasing the diffusivity in the hydration
domain of the skin and rearranging the lipid bilayer in the
stratum corneum.