Research findings

No. 32 The evaluation of CoQ10-γ-CD Complex in vitro skin absorption experiment

Summary

Coenzyme Q10 (CoQ10) is a potent antioxidant against oxidative damage to skin. But the amount of CoQ10 in tissue is reduced with age. To supply the reduction, we evaluated some formulations of CoQ10-γ-CD Complex in vitro skin absorption experiment and found that both aqueous solubility and absorption of CoQ10 in the tissue culture were significantly enhanced by the combination of CoQ10-γ-CD Complex with dipotassium glycyrrhizate (GZK2).

Effect of CoQ10 on human skin

Solubility experiment

Some skin problems were improved by the oral intake of high absorption CoQ10-γ-CD Complex.
Is it possible to complement CoQ10 to skin directly?

The solubilization study of CoQ10 was made by adding various solubilizing agents as the third ingredient to CoQ10 or CoQ10-γ-CD Complex.

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Furthermore, the effect of solubilization of CoQ10 was estimated in the skin absorption experiment.

Solubilization of CoQ10 by solubilizing agents

Various solubilizing agents ware added to CoQ10 or CoQ10-γ-CD complex aqueous suspension, and then the concentration of CoQ10 in water was measured by HPLC.

Solubilization of CoQ10 by GZK2

GZK2 was added to CoQ10 or CoQ10-γ-CD complex aqueous suspension, and then the concentration of CoQ10 in water was measured by HPLC.

"LabCyte EPI-MODEL" The human three-dimensional cultured epidermis model

The human three-dimensional cultured epidermis model
"LabCyte EPI-MODEL (Japan Tissue Engineering Co., Ltd.)"

This is multi-layered epidermis model cultured by using normal human skin cells.
It's characterized by the morphological resemblance to human skin.
It consisted of stratum basale, stratum spinosum, stratum granulosum and stratum corneum.
It's in no danger of species difference, since human cells are utilized.
Test results are reproducible because of small well-to-well and lot-to-lot variation.

Procedure of skin absorption experiment

Uptake of CoQ10 to epidermis

The uptake of CoQ10 to human three-dimensional culture epidermis "LabCyte EPI-MODEL" in various test materials was measured by HPLC.

Conclusion

The solubility of CoQ10 was increased by the combination of CoQ10-γ-CD complex and GZK2, then it is confirmed that very high solubility more than 2,000 μg/mL can be reached. On the other hand, in case of not complexed CoQ10, solubility of CoQ10 was not increased in spite of GZK2 addition.
It may be assumed that the intermolecular force between CoQ10 molecules can be reduced by the complexation with γ-CD.
In the skin absorption experiment, the uptake of CoQ10 to epidermis was increased by the combination of CoQ10-γ-CD complex and GZK2.