Preparation of turmeric oil-loaded chitosan-alginate biopolymeric nanocapsules

Preparation of chitosan-alginate nanocapsules containing turmeric oil was carried out by emulsification of turmeric oil in aqueous sodium alginate solution and gelification with calcium chloride and chitosan, followed by solvent removal. The process parameters were optimized by variation of the molecular weight of chitosan, the chitosan/alginate mass ratio, and the order of addition of calcium chloride and chitosan in the formulation. The nanocapsules were characterized based on average size, zeta potential, morphology, percent recovery, loading capacity of turmeric oil, nanocapsule yield, and stability at 4 °C and 25 °C. The characteristics of the nanocapsules were dependent on the molecular weight and amount of chitosan. Chitosan with a low molecular weight was required to produce small nanocapsules. At a fixed chitosan/alginate mass ratio of 0.1:1, addition of chitosan after calcium chloride was found to be optimal for improving the physical stability, percent recovery of turmeric oil and nanocapsule yield, while maintaining the loading capacity of the turmeric oil.