Chitosan nanoparticles and microspheres for the encapsulation of natural antioxidants extracted from Ilex paraguariensis

The use of chitosan for the encapsulation of active components has gained interest in the last years due to its mucous adhesiveness, non-toxicity, biocompatibility and biodegradability. The benefits of encapsulating active agents in a polymer matrix include their protection from the surrounding medium or processing conditions and their controlled release. In this study chitosan nanoparticles and microspheres were obtained for the encapsulation of yerba mate. Nanoparticles were prepared by ionic gelation of chitosan hydrochloride and sodium tripolyphosphate. The active components were added to the sodium tripolyphosphate solution and this was added dropwise to the chitosan hydrochloride solution while stirring. Microspheres were prepared by the spray-drying method. In this case, antioxidants were added to the chitosan solution and the mixture was spray-dried. The effect of the encapsulating systems on the active compound stability and its release properties was analyzed. The products obtained allowed to control the release of natural antioxidants and therefore these encapsulating methods are a promising technique for nutraceutical and cosmetic applications. (C) 2010 Elsevier Ltd. All rights reserved.