Production of soybean phosphatidylcholine-chitosan nanovesicles by reverse phase evaporation: a step by step study

In the present work, we describe the preparation of composite nanovesicles containing soybean phosphatidylcholine and polysaccharide chitosan by the reverse phase evaporation method. Nanovesicles free from chitosan prepared in the same way were studied as reference. The production method involves the preparation of reverse micelles followed by the formation of an organogel, which is dispersed in water to yield the final liposomal structures. Structural changes in each step of the nanovesicles preparation were studied by means of static and dynamic light scattering as well as small angle X-ray scattering. Chitosan was also fully characterized in solution. The hydrodynamic radius of the composite nanovesicles is in the range of 174-286 nm, depending on the chitosan contents. A comparison with nanovesicles free from chitosan indicates the existence of higher contents of multilamellae structures in the composites, as well as improved stability in water. (c) 2005 Elsevier Ireland Ltd. All fights reserved.