Enhanced solubility and bioavailability of coenzyme Q10 via co-amorphous system using stevioside

Coenzyme Q10 (CoQ10) plays a vital role in aerobic respiration and cardiovascular diseases; however, its application is limited owing to poor water solubility. In this study, equimolar CoQ10 and stevioside (STE) formed a co-amorphous (CM) system by lyophilization, and its solubility was approximately 63 times higher than that of CoQ10. Through crystal, thermodynamic, and morphological characterization of the formula, the formation of the CM system was confirmed. The intermolecular interactions were investigated by spectroscopies. The relationship of 8 intermolecular interaction sites between the two was confirmed via molecular dynamics simulation, firmly indicating the strong intermolecular forces. Further, CM products remained stable even under accelerated storage conditions, equivalent to 1 year at room temperature. Meanwhile, the area under curve (AUC) values increased by 5 times in the in vivo bioavailability study. In conclusion, the CoQ10 was transformed into an amorphous structure by initially employing STE through intermolecular interactions to enhance solubility.