Enhancement of oral bioavailability of coenzyme Q 10 by complexation with γ-cyclodextrin in healthy adults

Abstract

The objective of this study was to determine the effect of molecular encapsulation of coenzyme Q 10 (CoQ 10) by complexation with γ-cyclodextrin ( γ-CD) (CoQ 10- γ-CD) compared with a mixture of CoQ 10 with microcrystalline cellulose (CoQ 10-MCC) on absorption and bioavailability of CoQ 10 in supplement form in healthy adults. Twenty-two volunteers received a single dose of a 150-mg capsule containing 30 mg CoQ 10 under fasting conditions in an open-label, crossover design with a 2-week washout period. Blood was collected before dosing and after dosing periodically over 48 hours. Plasma levels of CoQ 10 were determined by high-performance liquid chromatography using an electrochemical detector and an online reduction system. After 6 and 8 hours of dosing there was a significant increase in mean CoQ 10 plasma levels of subjects after a single oral administration of the CoQ 10- γ-CD capsule compared with those with the CoQ 10-MCC capsule. In addition, the mean plasma levels at 24 and 48 hours tended to be higher after CoQ 10- γ-CD administration in comparison with CoQ 10-MCC administration. The area under the plasma CoQ 10 concentration curve and the maximum plasma concentration ( C max) values as well as their corresponding log-transformed values, log area under the plasma CoQ 10 concentration curve, and log C max for the CoQ 10- γ-CD formulation were significantly higher than those for the CoQ 10-MCC formulation. These results indicate that the oral absorption and bioavailability of CoQ 10 in healthy adult volunteers could be significantly enhanced by complexation with γ-CD, suggesting the potential use of γ-CD as formulation aid for orally administered CoQ 10.