Physicochemical characterization, photo-stability and cytotoxicity of coenzyme Q10-loading nanostructured lipid carrier.

Nanostructured lipid carrier (NLC) is prospective active ingredients delivery systems based on combinations of solid lipids and liquid oil. Aqueous dispersion of NLC was prepared via hot high pressure homogenization technique. The CoQ10-NLC aqueous dispersion was prepared in order to improve the water solubility, photo-stability of Coenzyme Q10 (CoQ10). The physicochemical characterization parameters of CoQ10-NLC have been explored regarding particle size, zeta potential, polydispersity index (PDI) value and stability of CoQ10, which is an antioxidant. HPLC was employed to monitor the loading of CoQ10 encapsulated in NLC system. Morphology profile and hydrophobicity/hydrophilicity were determined and analyzed using atomic force microscopy (AFM) and water contact angle measurements, respectively. Infrared (IR) spectrometry was exploited to confirm the possible interaction and complex formation between CoQ10 and lipids. The photo-stability of CoQ10 was powerfully improved by NLC, more than 80% of CoQ10 remained unchanged in one month under natural daylight, while the retention of free CoQ10 only 33.5% under the same conditions. CoQ10-NLC offered comparatively high protection. The retention of CoQ10 in NLC system was about 65% after five-month exposure to natural daylight, the retention of free CoQ10 only 13.3%. The CoQ10 in the NLC-based formulation showed considerably enhanced photo-stability compared with CoQ10 itself, and displayed the better protection of CoQ10. The obtained results opened new perspectives on the photo-stability of CoQ10. The MTT analysis determined CoQ10-NLC lower cytotoxicity. In conclusion, the present investigation demonstrated that the CoQ10-NLC significantly improved the water solubility, especially the enhancement of photo-stability of CoQ10 under natural daylight.