Synthesis and Evaluation of Different Fatty Acid Esters Formulated into Precirol (R) ATO-Based Lipid Nanoparticles as Vehicles for Topical Delivery

A series of isopropyl fatty esters having different chain length (C13—C23) were synthesized and formulated
in lipid nanoparticles based on Precirol® ATO to evaluate their effect on the physicochemical properties of these
latter. Moreover, drug loading and skin permeation of Econazole nitrate, chosen as a lipophilic model drug, were
evaluated as well. The obtained nanosystems, prepared by high shear homogenization method, had a mean diameter
ranging from 180 to 280 nm and showed an encapsulation efficiency of about 100%. Ex vivo permeation results
demonstrated a parabolic correlation between permeation effect and chain length of the fatty esters present
in the lipid nanoparticles formulated in hydrophilic gels. The maximum flux of drug was observed for the
nanoparticles containing esters with 17 and 19 carbon atoms, suggesting that these formulations may constitute a
potential carrier for topical delivery of econazole nitrate.