Abstract

REVIEW ON SOLVENT EVAPORATION TECHNIQUE: A PROMISING METHOD FOR MICROENCAPSULATION

Deepa Nag* and Bipul Nath

Abstract

Microencapsulation is the process of surrounding or enveloping one substance within another substance on a very small scale, yielding capsules ranging from less than one micron to several hundred microns in size. The encapsulation efficiency of the micro particles or microsphere or microcapsule depends upon different factors like concentration of the polymer, solubility of polymer in solvent, rate of solvent removal, solubility of organic solvent in water etc. Microencapsulation is a well-established dedicated to the preparation, properties and uses of individually encapsulated novel small particles, as well as significant improvements to tried-and-tested techniques relevant to micro and nano particles and their use in a wide variety of industrial, engineering, pharmaceutical, biotechnology and research applications Substances may be microencapsulated with the intention that the core material be confined within capsule walls for a specific period of time. Alternatively, core materials may be encapsulated so that the core material will be released either gradually through the capsule walls, known as controlled release or diffusion, or when external conditions trigger the capsule walls to rupture, melt, or dissolve. This review article focuses on the use of the Solvent Evaporation technique, for the preparation of polymeric microcapsules, and modifications that have been developed over the years to improve the results obtained with this technique. The author also highlights some of the aspects of choices of process parameters, challenges and limitations of drug microencapsulation in real life. The review covers encapsulation materials, physics of release through the capsule wall and / or desorption from carrier, techniques of preparation, many uses to which microcapsules are put.

Keywords: Microencapsulation, Core Materials, Coating Materials.