A critical review of microencapsulation methods, mechanisms, and applications

Across industries, the demand for high-performance and environmentally responsible products is reshaping the design of functional materials. Microencapsulation, a technique that entrains active agents within microscopic shells, has emerged as an effective strategy to protect, stabilise, and control the release of sensitive compounds. Initially developed for specialised applications, it is now widely used in pharmaceuticals, food technology, cosmetics, agriculture, textiles, and advanced materials. This review presents an overview of microencapsulation technologies, covering core-shell structures, material selection, and major fabrication methods such as coacervation, solvent evaporation, spray drying, layer-by-layer assembly, and co-extrusion. The influence of processing conditions, capsule morphology, and release mechanisms on encapsulation efficiency and performance is critically discussed. In addition, current challenges including durability, scalability, and environmental concerns are highlighted. The review also outlines emerging research directions, particularly the development of biodegradable polymers, solvent-free processes, and stimuli-responsive systems for sustainable and advanced functional applications.