Enhancing solubility and bioavailability of coenzyme Q10: formulation of solid dispersions using Soluplus® as a carrier.

Improving the aqueous solubility of poorly soluble compounds have been a major issue in the pharmaceutical industry. In the present study, binary amorphous solid dispersions (SDs) of Coenzyme Q10 (CoQ10), a biopharmaceutics classification system (BCS) II compound and Soluplus® were prepared to enhance the solubility and pharmacokinetic properties compared to crystalline CoQ10. SDs were prepared with different ratios of CoQ10 and Soluplus® (1:3, 1:5, and 1:7) using spray drying technology, and the physicochemical properties of the SDs were evaluated. X-ray powder diffraction, differential scanning calorimetry, and scanning electron microscopy suggested the conversion of the crystalline form of CoQ10 to a binary amorphous system in the SDs. Fourier transform infrared spectroscopy revealed no potential interactions between CoQ10 and Soluplus®. The solubility of the optimal SD formulation (SD 1:7) was approximately 9000-fold higher than that of crystalline CoQ10, and the increment was Soluplus® concentration dependent. As a result, optimized SD 1:7 also showed significantly enhanced dissolution rate where maximum drug release was observed within 30 min in two different dissolution media. Moreover, in contrast to crystalline CoQ10, CoQ10 SDs showed improved pharmacokinetic parameters. Thus, the SD 1:7 formulation is expected to improve biopharmaceutical properties and therapeutic efficacy of CoQ10.