Formulation Techniques of Multiple Emulsions (W/O/W, O/W/O), their Release Kinetics and Application. A Review

. Multiple emulsions have a lot of potential as encapsulating systems in food, cosmetics, and phar- maceuticals. However, performing release kinetics in these systems is challenging because of their complicated structure. In personal care products, multiple-phase emulsions are becoming more popular as alternatives to plain emulsions. The gradual and controlled release of the contents is one of the key advantages of complex emulsions over basic emulsions. One-step or two-step emulsification techniques, phase inversion, preparation using microfluidics devices, spontaneous multiple emulsion preparations, preparation using a microporous glass membrane, formulation of shear rate-sensitive multiple emulsions, multiple emulsions by controllable microfluidic production are few of several techniques utilized to prepare emulsions. Two-step emulsification procedures are the most prevalent. A basic strategy produces many results. Emulsifiers or mixtures of emul- sifiers with HLB values near the required HLB of the oil phase are optimal for creating stable emulsions. The dissolution paddle apparatus, which explains the percentage of drug release from numerous emulsions, well explains the release kinetics of drug substances from several emulsions.