Impact of hydrophilic substances on Ostwald ripening in emulsions stabilized by varied hydrophilic group surfactants

This study investigated the impact of water-soluble substances on Ostwald ripening in emulsions stabilized by surfactants with different head groups (Brij S20 and Tween 60). Adding ≥20% (w/w) corn oil to the oil phase effectively inhibited Ostwald ripening of n-decane emulsions due to compositional ripening. The presence of glucose, maltose, or glycerol in the aqueous phase of the emulsions decreased the Ostwald ripening rate, regardless of emulsifier type. However, the impact of propylene glycol depended on emulsifier type, accelerating Ostwald ripening in Brij S20-stabilized emulsions but having little effect in Tween 60-stabilized emulsions. This effect was mainly attributed to the ability of propylene glycol to alter interfacial characteristics. When emulsions were fabricated with a mixture of n-decane and corn oil, glucose and maltose were still effective in inhibiting Ostwald ripening, but glycerol lost its ability. These results have important implications for formulating emulsion-based delivery systems with enhanced shelf life.