Abstract
Recently caffeine has been investigated for the treatment of various types of cancers upon oral administration There is also some evidence that dermally applied caffeine can protect the skin from skin cancer caused by sun exposure. Therefore nanoemulsion rot mulation of caffeine for transdermal drug delivery was developed and evaluated in the present investigation Different w/o nanoemulsion formulations of caffeine weie prepared by oil phase titration method. Thermodynamically stable nanoemulsions were characterized for morphology, droplet size, viscosity and refractive index The in vitro skin permeation studies were perfoimed on Fianz diffusion cell using fat skin as permeation membrane The in vitro skin permeation profile of optimized formulation was compared with aqueous solution of caffeine Significant increase in permeability parameters was observed in nanoemulsion formulations (P< 0 05) as compaiecl to aqueous solution of caffeine The steady-state flux (/) and permeability coefficient (Ki,) for optimized nanoemulsion formulation (C12) were found to be 147 55 8 21 gg/cm(2)/h and 1 475 x 10(-2) +/- 0 031 x 10(-2) cm/h. respectively Enhancement ratio (Er) was found to be 17 37 in optimized formulation C12 compaiecl with other formulations Overall these results suggested that w/o nanoemulsions are good carriers for transdei mal dein/el y of caffeine. (C) 2009 Elsevier B V All rights reserved