A Critical Reveiw on Nanoemulsion: Advantages, techniques and characterization

Nanoemulsions have small droplet size and are kinetically stable colloidal systems. These are the thermodynamically stable isotropic system in which two immiscible liquids are mixed to form a single phase by means of appropriate surfactant and co-surfactant. Nanoemulsion droplet sizes fall typically in the range of 20-200 nm and shows narrow size distribution. They have enhanced functional properties in comparison to conventional emulsions. The composition and structure of the nanoemulsions can be controlled for the encapsulation and effective delivery of bioactive lipophilic compounds. Nanoemulsions have potential application in the food industry for the delivery of nutraceuticals, coloring and flavoring agents, and antimicrobials. This review aims to provide consolidated information regarding various formulation and characterization techniques developed for nanoemulsions. Various characterization techniques for nanoemulsions include determination of entrapment efficiency, particle size, polydispersity index, zeta potential as well as characterization through differential scanning calorimetry, Fourier-transform infrared spectroscopy and transmission electron microscopy.