Melt Dispersion Technique for Encapsulation

Abstract

Encapsulation involves the coating or entrapment of a pure material or a mixture into another material. The coated or entrapped material, usually a liquid, is known as the “core” or “active” material, while the coating material is known as the “wall” material.1 At the end of any applicable technique for encapsulation, the nal products called particles (micro-or nanoparticle depending on the size) can be dried or not.2 Considering the aforementioned facts, a number of technologies have been used in the preparation of encapsulates, such as spray-drying, uidized-bed coating, spray-cooling, extrusion technologies, emulsication, inclusion encapsulation, coacervation, nanoencapsulation, and liposome entrapment. There are a number of excellent recent reviews summarizing all encapsulation processes.2-8 Although the principle of dispersing of a molten matrix has been frequently employed for production of encapsulates, there are not many, if any, papers overviewing the processes and equipments utilizing this principle. The aim of this chapter is to describe technologies utilizing melt dispersion, melt spraying, melt emulsication, and melt homogenization. It also surveys applications of melt dispersion, describes its advantages and limitations, and emphasizes trends and innovations.