Novel Lipid-Free Nanoformulation for Improving Oral Bioavailability of Coenzyme Q10

To improve the bioavailability of orally administered lipophilic coenzyme Q10 (CoQ10), we formulated a novel lipid-free nano-CoQ10 system stabilized by various surfactants. Nano-CoQ10s, composed of 2.5% (w/w) CoQ10, 1.67% (w/w) surfactant, and 41.67% (w/w) glycerol, were prepared by hot high-pressure homogenization. The resulting formulations were characterized by particle size, zeta potential, differential scanning calorimetry, and cryogenic transmission electron microscopy. We found that the mean particle size of all nano-CoQ10s ranged from 66.3 ± 1.5 nm to 92.7 ± 1.5 nm and the zeta potential ranged from -12.8 ± 1.4 mV to -41.6 ± 1.4 mV. The CoQ10 in nano-CoQ10s likely existed in a supercooled state, and nano-CoQ10s stored in a brown sealed bottle were stable for 180 days at 25 °C. The bioavailability of CoQ10 was evaluated following oral administration of CoQ10 formulations in Sprague-Dawley rats. Compared to the values observed following administration of CoQ10-Suspension, nano-CoQ10 modified with various surfactants significantly increased the maximum plasma concentration and the area under the plasma concentration-time curve. Thus, the lipid-free system of a nano-CoQ10 stabilized with a surfactant may be an effective vehicle for improving oral bioavailability of CoQ10.