ABSTRACT
The development of topical products generally requires the screening of large
numbers of formulations in order to optimize drug disposition. Changes in
vehicle can also result in local or systemic toxicity, and an early indication of
potential toxicity will facilitate formulation development. To this end, a new
in vitro test system was developed to efficiently determine skin absorption and
potential chemical toxicity. Sheets of viable excised pig skin were sandwiched
between two standard 24 well plates. The lower wells contained receptor fluid
and a magnetic stirrer. The visceral side of the skin sample was bathed by tissue
culture medium that maintained skin viability. The medium also served as a sink
for skin penetrants, their metabolites, and excretion products from the skin. The
upper wells were opened to the atmosphere for topical application.
