Background: The tocopherol-based excipient, TPM, when incorporated into a medium-chain
triglyceride (MCT)-based lipid formulation, has been previously shown to improve the solubilization of
Coenzyme Q10 (CoQ10) during in vitro digestion which is strongly correlated with enhanced exposure
Methods: The current study aimed to gain further understanding of the MCT + TPM co-formulation, by
assessing the formulation performance under fasted and fed in vitro digestion conditions, with different
drug and excipient loading levels. Natural and synthetic-derived TPM were equivalent, and with d-α-
tocopherol polyethylene glycol 1000 succinate (TPGS) outperformed other derivatives in enhancing the
solubilisation of CoQ10 during digestion.
Result: Fed conditions significantly improved the solubility of CoQ10 during in vitro digestion of the
formulation in comparison with fasted conditions. The addition of TPM at 10% (w/w) of the total MCT
+ TPM provided optimal performance in terms of CoQ10 solubilization during digestion.
Conclusion: The results further highlights the potential of TPM as an additive in lipid formulations to
improve the solubilization and oral bioavailability of poorly water-soluble compounds.