Multi-Compartment Pharmacokinetics and Tissue Bioavailability of Coenzyme Q10 from a Phospholipid-Based...

Area of Science:

• Pharmacokinetics and Drug Delivery
• Nutraceutical Formulation Science
• Cellular Biology

Background:

• Current Coenzyme Q10 (CoQ10) studies often focus solely on plasma bioavailability.
• Limited understanding exists regarding intracellular delivery, tissue distribution, and absorption pathways of CoQ10.
• This research addresses the need for a more comprehensive evaluation beyond plasma metrics.

Purpose of the Study:

• To evaluate a novel phospholipid-based self-nanoemulsifying CoQ10 delivery system (SNEDDS).
• To assess CoQ10 delivery across multiple compartments: plasma pharmacokinetics, erythrocyte uptake, and tissue distribution.
• To investigate indicators suggesting a potential contribution of intestinal lymphatic transport to CoQ10 absorption.

Main Methods:

• Characterization of SNEDDS formulation (droplet size, zeta potential, drug loading).
• Assessment of cellular metabolic activity in Caco-2 cells using MTT assay.
• In vivo pharmacokinetic and tissue distribution studies in Sprague-Dawley rats, quantifying CoQ10 via HPLC.

Main Results:

• The SNEDDS formed a stable nanoemulsion and enhanced mitochondrial metabolic activity in Caco-2 cells.
• In vivo, SNEDDS increased plasma Cmax (2.7-fold) and AUC0-24h (1.5-fold) compared to crystalline CoQ10, achieving 149% relative bioavailability.
• Erythrocyte and tissue CoQ10 concentrations increased significantly (1.3-4.5-fold), with a liver-to-intestine ratio shift suggesting potential lymphatic transport.

Conclusions:

• The phospholipid-based SNEDDS effectively enhances systemic, cellular, and tissue-level CoQ10 delivery.
• The observed tissue distribution pattern supports the hypothesis of intestinal lymphatic transport involvement.
• Further dedicated studies are required to directly confirm the contribution of lymphatic transport to CoQ10 absorption.