Development and Stability Assessment of Coenzyme Q10-Loaded Oil-in-Water Nanoemulsions Using as Carrier Oil: Extra Virgin Olive and Olive-Pomace Oil

Abstract

Coenzyme Q10 (CoQ10) presents multiple health benefits as an essential molecule for every cell and as an excellent antioxidant compound; however, its oral intake is challenging due to its low water solubility. Oil-in-water (o/w) nanoemulsions are considered excellent delivery systems for CoQ10, offering high protection and controlled release of the bioactive compound. In the present study, CoQ10 nanoemulsions were prepared using extra virgin olive (EVOO) or olive-pomace oil (OPO) with Tween 20 and Tween 40. It was investigated the effect of environment (25 °C) and refrigerated (4 °C) storage on the nanoemulsion physical and chemical stability. The results showed that it is possible to form fine o/w nanoemulsions with the two oils and various emulsifiers’ concentrations. The physicochemical properties of the nanoemulsions were evaluated in terms of mean droplet diameter (MDD), polydispersity index (PDI), ζ-potential, turbidity, and CoQ10 physicochemical stability (RCoQ10%). EVOO proved able to form kinetically more stable nanoemulsions with high CoQ10 retention (74.01%), while OPO led to nanosized emulsions with lower CoQ10 retention (71.99%). It was also observed that CoQ10 retention increases as the oil concentration increases (6% w/w EVOO, RCoQ10 = 77.17 and 8% w/w EVOO, RCoQ10 = 79.89%). All the nanoemulsion formulations, after storage either at 4 °C or at 25 °C, remained in the nanosized range after 3 months, with high physical (MDD < 500 nm) and chemical stability (RCoQ10 = 52.87%). Finally, nanoemulsions with 4% w/w emulsifier concentration appeared kinetically and chemically more stable as they presented lower MDD variations during storage.