The success of the chemotherapeutic treatment of hydatid disease is based upon the drug ability to operate on the germinal layer and on the protoscolices of the hydatid cyst interior at adequate concentrations for sufficient periods. The goal of this study was to evaluate the ability of the drug diffusion through the cyst membrane from sheep hydatid cysts and the increase of drug concentration in the cyst environment. In the first part of this work, the permeation behaviour through the hydatid cyst membrane was studied with five model molecules, having different molecular descriptors (logP, molecular weight, polar surface area ...) onto static Franz glass diffusion cells. A good correlation has been observed between the permeation coefficient and the partition coefficient, log P (r=0.951). In the second part, albendazole-loaded nanoparticles (about 300 nm) prepared by the emulsion solvent evaporation method have shown a sufficient entrapment efficiency (36.4 +/- 6.4%) to raise the apparent solubility of albendazole. The diffusion of drug from the nanoparticles across the hydatid cyst membrane was also improved compare to albendazole suspension. These results have shown the interest of the albendazole-loaded nanoparticles for the treatment of hydatid cysts in the future.