Influence of Hydrophilic Surfactants on the W1–W2 Coalescence in Double Emulsion Systems Investigated by Single Droplet Experiments

Double emulsions are a promising formulation for encapsulation and targeted release in pharmaceutics, cosmetics food. An inner water phase is dispersed an oil phase, which again emulsified second phase. The encapsulated can be released via diffusion or coalescence, neither of desired during storage but might intended application. two interfaces double emulsion stabilized by hydrophilic lipophilic surfactant, to prevent the coalescence outer emulsion, respectively. This study focuses on influence surfactant actives therein droplet with O–W2 interface. Since difficult distinguish emulsions, single-droplet experiments were used quantify differences stability droplets. Different (PGPH PEG-30 dipolyhydroxylstearate) surfactants (ethoxylates, SDS polymeric) resulted huge stability. A drastic decrease was found some combinations, while other combinations droplets that could withstand longer. destabilization effect depended their concentration, still present at very low concentrations. spread time multiple determinations observed all formulations necessary statistical analysis discussed this work. measured stabilities single good accordance similar literature. Therefore, suggested fast evaluation potentially suitable future studies double-emulsion