ABSTRACT
From a practical viewpoint, it remains difficult to draw valid conclusions from the literature concerning the absorption level of a given compound. This is essentially due to the diversity of techniques used, animal species (Tregear, 1964; Winkelman, 1969), anatomical location (Marzulli, 1962; Lindsey, 1963), duration of application (Tregear, 1964), dose applied (Maibach and Feldman, 1969; Wester and Maibach, 1976), and vehicle used (Poulsen, 1973; Tregear, 1964). Furthermore, because this kind of research has interested scientists from widely differing disciplines, each worker has chosen or adapted the methodology to elucidate a particular problem.
