Abstract: 
Microencapsulation is a technique by which a layer of polymer or any other coating material is provided to small particles of solid or liquid substances. Microspheres are used for a number of purposes like in food industries, food preservation, drug formulations, and so on. Depending on purposes of use and production requirements, different methods are used. In case of drug formulations, microencapsules or microspheres facilitate masking bitter or undesirable taste of a substance, long duration of action, site-specific release, separation of incompatible substances, and protection against moisture degradation or oxidation, modifying elements’ physical characteristics. Microspheres can be produced in various ways. These methods can be categorized as physical, physicochemical and chemical methods. They can also be categorized as chemical and mechanical processes. Researchers have always explored different ways of microsphere production to discover new applications. In this review paper, we have highlighted different methods used for the microsphere and microcapsule preparation. Spray drying or congealing, coacervation and solvent evaporation techniques are most commonly used for drug formulation preparation. This research can be a guideline to find out the most suitable method of microsphere preparation depending on the desired output.

Keywords: Microsphere, Microcapsule, Solvent Evaporation, Spray Drying, Coacervation.