Permeation studies comparing cobra skin with human skin using nicotine transdermal patches

Cobra skin (Naja Naja Khaotia) was used as a barrier for an in vitro permeation study using nicotine. Fluxes of nicotine that permeated from Nicotinell through cobra skin (CS) taken from the head, body, and tail were 233.93 +/- 16.08, 206.87 +/- 19.00, and 211.26 +/- 22.93 micrograms/cm2/hr1/2, respectively (n = 6). This indicated no significant difference (p > .05). Abdominal human epidermis (HE), obtained from cadavers, and the CS provided identical permeation kinetics for nicotine, which can be described by Mt = 4M alpha (Dt/pi L2)1/2. The mean flux of nicotine formulated as an acrylic transdermal patch that permeated through HE was 137.92 +/- 67.79 micrograms/cm2/hr1/2 (4 specimens, n = 12), whereas that through CS was 180.13 +/- 41.05 micrograms/cm2/hr1/2 (4 specimens, n = 15). The ratio of the fluxes of nicotine from formulated patches having three different nicotine contents using CS and HE was 1.22 to 1, respectively, for each of the patches irrespective of nicotine content. The coefficients of variation of the nicotine permeated were 22.79% and 49.15% for CS and HE, respectively, that is, a narrower variation of results was obtained with CS. This indicated that CS could be used for nicotine permeation studies.