Preparation, Characterization and Evaluation of Curcumin Nanodispersions Using Three Different Methods - Novel Subcritical Water Conditions, Spontaneous Emulsification and Solvent Displacement

Curcumin as a lipophilic bioactive compound can be incorporated into water-based formulations when it turns into curcumin nanodispersions. In fact, nanodispersion systems, increase curcumin bioavailability, solubility and stability, and furthermore increase curcumin uses in aqueous food and pharmaceutical formulations. Present study focuses on the preparation of curcumin nanodispersions under subcritical water conditions (temperature of 120 degrees C and pressure of 1.5 bar for 2 h) and using selected another two different methods namely, spontaneous emulsification and solvent displacement. Lecithin as carrier oil, Tween 80 as emulsifier and polyethylene glycol as co-surfactant, with a ratio of 1:8:1, were used in all the preparation techniques. Obtained results indicated that curcumin nanodispersions with smallest mean particle size (70 nm), polydispersity index (0.57), curcumin loss (5.5%) and turbidity (0.04 Nephelometric Turbidity Unit), and maximum loading ability (0.189 g/L), loading efficiency (94.5%) and conductivity (0.157 mS/cm) were obtained under subcritical water conditions. The results also exhibited that the prepared spherical curcumin nanoparticles in the water by this technique had desirable physical stability as their mean zeta potential value was (-12.6 mV). It also observed that, as compared to spontaneous emulsification and solvent displacement methods, the prepared curcumin nanodispersions via subcritical water method had highest anti-oxidant and antibacterial activities.