Nanoemulsions; preparation, characterization and applications

Insolubility of the nonpolar compounds in water causes some problems and limitationsincluding their lower bioavailability and mixing in the aqueous formulations. In addition to, thenonpolar components are more sensitive to oxygen and lights and their properties drasticallyreduce when they expose to the air. Nanoemulsions are one of the main finding of theresearchers to increase the stability of these types of components in the water and to decreasetheir sensitive in the environment. Nanoemulsions contain two immiscible phases which dropletsof a phase are disperses in another one [1]. There are two basic types of nanoemulsions mostlikely to be formed depending on the composition that is oil-in-water (O/W) or water-in-oil(W/O) [2]. Nowadays, several methods for preparing nanoemulsions are available. They can beproduced using both low-energy, in which a change of curvature and a phase transition takesplace during the emulsification process and high-energy protocols that consist of the applicationof high mechanical energy during emulsification e.g., high pressure homogenization ormicrofluidization. Several techniques has been used for characterization of nanoemulsions. Themorphology of the nanoparticles is studied by TEM, SEM and AFM. Bioactive components ismeasured by HPLC and UV-visible. The specific surface area of nanoemulsion can be measuredusing the BET analysis [3]. DLS, SEM, FESEM and TEM analysis of the nanoemulsions isperformed to determine the droplet size. The surface electrical charge (ζ-potential) onnanoemulsion droplets is measured by using a particle electrophoresis instrument.Nanoemulsions are beneficial for encapsulating, protecting and delivering the poorly watersolublebioactive components for both functional food and pharmaceutical applications.Nanoemulsions are largely used in the areas of food, cosmetic, paints, reduce waste medicineand pharmaceutics applications [4].

کلیدواژه ها:

Nanoemulsions ، Bioavailability ، Bioactive Compounds ، Surface Area