Bioavailability enhancement of coenzyme Q: An update of novel approaches.

Coenzyme Q (CoQ) is an essential, lipid-soluble vitamin involved in electron transport in the oxidoreductive reactions of the mitochondrial respiratory chain. Structurally, the quinone ring is connected to an isoprenoid moiety, which has a high molecular weight. Over the years, coenzyme Q has become relevant in the treatment of several diseases, like neurodegenerative disorders, coronary diseases, diabetes, hypercholesterolemia, cancer, and others. According to studies, CoQ supplementation might be beneficial in the treatment of CoQ deficiencies and disorders associated with oxidative stress. However, the water-insoluble nature of CoQ is a major hindrance to successful supplementation. So far, many advancements in CoQ bioavailability enhancement have been developed using novel drug carriers such as solid dispersion, liposomes, micelles, nanoparticles, nanoemulsions, self-emulsifying drug systems, or various innovative approaches (CoQ complexation with proteins). This article aims to provide an update on methods to improve CoQ solubility and bioavailability.