Formulation and characterization of loaded rosmarinic acid solid lipid nanoparticles

During the last decade has been a growing interest in the formulation of new food and nutraceutical products containing compounds with antioxidant activity. Unfortunately, certain compounds such as polyphenols are not stable when incorporated in certain food matrices. The use of solid lipid nanoparticles (SLNs) has been extensively reported and represents an alternative carrier system to traditional colloidal carriers. Furthermore, SLNs combine advantages such as biocompatibility and biodegradability, physical stability, protection of incorporated compounds, controlled release and specific targeting (Parhi and Suresh, 2010). The increasing demand for functional foods with beneficial effects for human health, has opened the doors to the use of SLN in the food industry, with the incorporation of natural compounds with beneficial purposes. With this aim, SLNs were prepared by a hot melt ultrasonication method using Witepsol E85 as lipid and Tween 80 as surfactant. The effects of lipid proportion in the lipid mixture and surfactant concentration were evaluated. Also, the stability of the nanoparticles during 28 days was tested in aqueous solution stored at 4 ºC, tracking the mean particle size, polydispersity index (PI) and zeta potential (ZP). Thermal analyses of SLNs were performed using DSC (Differential Scanning Calorimetry) and crystallinity index (CI%) was obtained through enthalpy values of SLN formulations and raw materials. The loading efficiencies as well surface properties and morphology were also evaluated.