Nanoemulsions and topical creams for the safe and effective delivery of lipophilic antioxidant coenzyme Q10.

Emulsion-based delivery systems have been developed to increase the topical bioavailability of lipophilic active compounds within skin membrane. The aim was to develop nanoemulsion from natural sources (rapeseed oil) with the same sources of pure phospholipids (lecithin) rich on mono and polyunsaturated fatty acids for encapsulation of hydrophobic antioxidant (Coenzyme Q10 ) giving nanoemulsion with double functionality. Nanoemulsions were used for cream preparation using xanthan gum and carboxylmethylcellulose as texturizing agents. The physico-chemical properties, toxicity and biocompatibility were evaluated. Physical stability was followed under different storage temperatures (25; 37 and 50 °C) for one month and revealed stable systems with 150 nm particle size. Anionic thickening addition influenced the electrophoretic mobility but not the size distribution. The addition of polyanionic thickening in nanoemulsions promoted negative surface charge that increased electrostatic repulsive forces between droplets avoiding destabilization phenomena such as coalescence and Ostwald ripening. Moreover, chemical stability evaluation of components confirmed the absence of interactions. FTIR analysis indicated the vibration band position of cis double stretching of unsaturated fatty acids between 3009 and 3006 cm-1 , which characterized the non-oxidized oils with same intensities before and after sonication. Antioxidants measurement shown that CMC significantly reduced antioxidant activity due to masking action of CoQ10 functional groups by the carboxylmethylcellulose gum conversely to xanthan gum addition. Finally, in vitro biocompatibility results shown that CoQ10 protected the DNA, and xanthan gum improve glucose metabolism inducing a better cell growth, while carboxymethylcellulose which was not metabolized by fibroblast cell inducing lower growth rate.