Shed Skin of Ophiophagus hannah: Structural Topography and In Vitro Permeation of Nicotine and Phenol

Scales of the dorsal portions of shed skin of king cobras (Ophiophagus hannah) was used as the barrier membrane for in vitro permeation of nicotine and phenol at toxic or irritable concentration levels. The scales were placed between solutions of nicotine or phenol in a donor solution at pH 5.6 and a receptor solution at pH 7.4. Cumulative amounts of nicotine and phenol permeated, measured by UV-spectrophotometry which was checked by HPLC, showed a linear relationship with time (r² > 0.99), giving permeation rates of 3.76, 8241.98 µg cm^-2 h^-1 and permeability coefficients of 0.38×10^-3, 90.2×10^-3 cm h^-1, respectively. Photomicrographs of the scales by scanning electron microscope (SEM) revealed 3 layers of which the innermost acting as the permeation barrier. Nicotine and phenol passed the micropits of the outer layer of the scales into the middle space where the compounds being reserved and then permeated the innermost layer of the skin. It is likely that this might be the pathway that these dose-dependent compounds were absorbed through snake skins.