Effect of lipid nanoparticles containing fatty alcohols having different chain length on the ex vivo skin permeability of Econazole nitrate

The aim of this study was to investigate the effect of saturated fatty alcohols having different chain length (C-12-C-18), formulated into Precirol-based lipid nanoparticles, on the ex vivo skin permeability of Econazole nitrate. Nanoparticles were prepared by o/w high shear homogenization using a mixture of Precirol and fatty alcohol as the lipid phase. A formulation containing only Precirol was used as a comparison. Lipid nanoparticles were characterized in terms of particle size, encapsulation efficiency and crystalline structure. After incorporation into hydrogels, ex vivo drug permeation tests were carried out through porcine stratum corneum. The particles had a mean diameter below 200 nm and the encapsulation efficiency ranged from 95 to 98%. Ex vivo permeation results demonstrated that the drug flux from formulations containing fatty alcohols increased as the alcohol chain length increased. The analysis of results revealed that the effect of fatty alcohols on the Econazole nitrate permeation is structure-dependent, and associated with an increase of the permeability coefficients that can improve the interaction between alcohols and skin lipids. (C) 2010 Elsevier B.V. All rights reserved.