Abstract

*Harshal Patil and Jyotsna Waghmare

ABSTRACT

Multiple emulsions are advanced colloidal delivery systems with hierarchical structures droplets in droplets in concentric phases providing considerable benefits over traditional emulsions. This extensive review examines the underlying science, formulation approaches, and growing applications of these multiphase systems. Water-in-oil-in-water (W/O/W) and oil-in-water-in-oil (O/W/O) systems allow for simultaneous encapsulation of incompatible constituents, sheltering of delicate actives, controlled release features, and improved stability profiles. The review analyses production methods such as two-step and one-step emulsification, membrane emulsification, microfluidic strategies, phase inversion techniques, and ultrasonication, reviewing their respective strengths and weaknesses. Emerging technological innovation in interface engineering, such as progress in amphiphilic particle stabilizers, responsive polymers, and accuracy manufacturing processes, has resolved long-standing stability issues, widening viable applications in several industries. The review emphasizes the innovative applications of multiple emulsions in cosmetics pharmaceuticals, agriculture, and food science. Though tremendous strides have been made, problems persist with large-scale manufacture, stability over long periods, and regulatory approval. As formulation methods and stabilization approaches become more sophisticated, multiple emulsions are set to play an ever more crucial role in creating next-generation products that address today's needs for increased functionality, sustainability, and multifunctionality.