Soudabeh Farid Aghaee - Masters Student of Islamic Azad University of Tabriz,
Babak Ghanbarzadeh - Professor at Tabriz university

Nanostructured lipid carriers (NLC) are a delivery system in which partial-crystallized lipid particles with mean radii ≤ 100 nanometers are dispersed in an aqueous phase containing emulsifier(s), as a potential delivery system may have some advantages in certain circumstances when compared with other colloidal carriers. NLC are a useful nutraceutical delivery system with high drug loading, encapsulation efficiency and stability. They also provide controlled release of encapsulated materials. Even though most NLC dispersions have a good steric repulsion and high stern potential due to the great absolute zeta potential, to enhance the electrostatic stability of these system the usage of appropriate preservatives such as phenols and their derivatives, aliphatic and aromatic alcohols, Organic mercury compounds, Quaternary ammonium compounds and Carbon acids can give a rise to the physical and chemical stability of NLC system. Among 11 different preservative mixtures only seven preservatives could be identified to be suitable for the preservation of NLC dispersions in which the Hydrolite 5 proved to be the best preservative for Q10-loaded NLC.