The clobetasol propionate-loaded nanoparticles were characterized before inclusion in the chitosan gel. The average particle size obtained by dynamic light scattering (DLS) was 248 ± 15 nm with a narrow nearly monodisperse distribution (Polidispersity Index 0.1105), while the ζ potential measured by phase analysis light scattering (PALS) had a positive value, i.e., +34 ± 2 mV, in agreement with previous data . Indeed, the structure of the particles has been investigated previously: chitosan and lecithin interact electrostatically to form essentially a multilayered structure . These particles are able to load lipophilic drugs in the phospholipid bilayers and the loading can be improved by adding pharmaceutical oils such as triglycerides or fatty acid esters. In fact, isopropyl myristate (IPM) affects the structure of the multilayer chitosan/lecithin nanoparticles by intercalating the phospholipid bilayers, allowing the loading of a much higher quantity of corticosteroid .