Ultra-small lipid nanoparticles for controlled release of coenzyme Q10: physicochemical characterization, antioxidant activity analysis, and hemolysis study

Coenzyme Q10 (CoQ10) is a potent antioxidant, anticancer and anti-inflammatory agent. However, the number of therapeutic applications of CoQ10 are limited because of its poor water solubility. In the present study, CoQ10-loaded ultra-small lipid nanoparticles (LPs) were prepared by melt-emulsification method. In order to examine the effect of the usage of liquid lipid in the structure of LPs, besides solid lipid nanoparticles (SLNs), nanostructured lipid carriers (NLCs) were also prepared by the use of olive oil in two of five different formulations. The effects of different formulations on the physicochemical properties of the carriers including size, zeta-potential, crystallinity and storage stability. These LPs were subjected to in vitro release studies, antioxidant activity analysis and ex vivo hemocompatibility tests. The kinetic model of the release rate of CoQ10 showed that the release profile can be controlled by adjusting the composition of the LPs in terms of lipid and emulsifier type. Antioxidant activity analysis showed that, nanoencapsulation of CoQ10 improved the hydroxyl scavenging activity of CoQ10 and decreases its EC₅₀ value. The best performance was obtained from NLC₂ in which 30% olive oil present with respect to total lipid. Furthermore, compared to CoQ10 solution, SLN₁ and SLN₃ exhibited an excellent sustained release profile. In conclusion, it is proved that the ultra-small LPs can improve the stability, bioavailability and antioxidant ability of CoQ10 whereas offered personalized and customizable biocompatible drug delivery systems with adjustable release kinetics.