Comparison of bioavailability of two ubidecarenone products in healthy Korean volunteers.

Objective: This study aimed to evaluate the bioavailability of two pharmaceutical products of ubidecarenone (coenzyme Q 10 , CoQ 10 ). Materials: Two brands (brand A and brand B) of commercial CoQ 10 hard capsules. Methods: Two brands of CoQ 10 capsules were administered at 100 mg dose to two groups of healthy volunteers, respectively, and blood samples were withdrawn at predetermined time intervals and assayed by a validated HPLC method with an electrochemical detector. Results and conclusions: Intra- and inter-day precision and inter-day accuracy were acceptable for all quality control samples including the lower limit of quantitation of 50 ng/ml. Recovery of CoQ 10 from human plasma was greater than 98.2%. CoQ 10 was stable in human plasma under various storage conditions. This method was applied to a pharmacokinetic study after oral administration of CoQ 10 hard capsules to healthy volunteers. The intrinsic CoQ 10 concentrations were measured for three consecutive days before drug administration, which were ranged between 0.68 and 0.79 μg/ml, and there was no statistically significant difference between groups. In brand A, the plasma concentration after administration of CoQ 10 was not higher than the intrinsic level, indicating that no significant drug absorption occurred, whereas considerably higher concentrations were obtained with brand B. The dissolution rates of brand A and B after 3 h were 0.35 ± 0.09 and 1.27 ± 0.16%, respectively. From the adjusted concentration-time curve, the AUC and t 1/2 of brand B were calculated to be 11.51 ± 5.76 μg · h/ml and 21.7 h, respectively. A mean C max of 0.32 ± 0.1 μg/ml was obtained at 7.9 h. In conclusion, it was found that bioavailability of CoQ 10 was significantly different depending on the formulations, and dissolution could be one of the important factors affecting CoQ 10 absorption.