Effect of electrolytes in the water phase on the stability of W1/O/W2 double emulsions

Preparation and Characterization of GX-50 and Vitamin C Co-encapsulated Microcapsules by a Water-in-Oil-in-Water (W1/O/W2) Double Emulsion–Complex Coacervation Method

“…Furthermore, excessive expansion or contraction could consequently lead to the release of encapsulated active ingredients into the continuous phase. So far, many researches have shown that the existence of a certain concentration of inorganic electrolytes (such as KCl, Na 2 CO 3 , MgCl 2 , and NaCl) can effectively balance the permeation pressure gradient between W 1 and W 2 phase so as to increase W 1 /O primary emulsion stability in W 1 /O/W 2 double emulsions. ,− Therefore, in this study, the most commonly added inorganic salt sodium chloride (NaCl) was added to the W 1 /O/W 2 double emulsion to investigate the effect of NaCl concentration (ω NaCl ) on its stability and the EE of GX-50 and Vc, as shown in Table .…”

“…11−14 Gelling the W 1 phase by adding a gelling agent into the W 1 phase is effective to enhance the viscosity of the W 1 phase. 15 The existence of a certain concentration of an inorganic electrolyte in the W 1 phase or in both W 1 and W 2 phases 16 and adding lactose into the W 2 phase 17 are considered to be effective in balancing the osmotic pressure between W 1 and W 2 phases. Optimizing primary emulsion formulation, such as phase volume ratio, emulsifier type, and concentration, and subsequently preparing a stable primary emulsion are crucial for the W 1 /O/W 2 double emulsion and complex coacervation.…”

“…So far, several stabilization strategies have been proposed by researchers in literature studies, such as increasing the internal water phase viscosity, balancing the osmotic pressure between W 1 and W 2 phases, optimizing primary emulsion formulation, enhancing interface strength of the W 2 phase, etc. − Gelling the W 1 phase by adding a gelling agent into the W 1 phase is effective to enhance the viscosity of the W 1 phase . The existence of a certain concentration of an inorganic electrolyte in the W 1 phase or in both W 1 and W 2 phases and adding lactose into the W 2 phase are considered to be effective in balancing the osmotic pressure between W 1 and W 2 phases. Optimizing primary emulsion formulation, such as phase volume ratio, emulsifier type, and concentration, and subsequently preparing a stable primary emulsion are crucial for the W 1 /O/W 2 double emulsion and complex coacervation .…”