Preparation and characterization of liposomal coenzyme Q10 for in vivo topical application.

Coenzyme Q10 (CoQ10) is an endogenous cellular antioxidant that is used as a nutritional supplement and for medicinal purposes. In recent in vivo investigations, cosmetically applied CoQ10 has demonstrated its ability to reduce photoaging, with a corresponding decrease in wrinkle depth. However, the bioavailability of topical CoQ10 is poor; the development of a practical topical formulation is therefore highly desirable. In this study, a liposomal formulation composed of soybean phosphatidylcholine (SPC) and alpha-tocopherol (Vit E) was utilized to encapsulate CoQ10 for topical application. The liposomes were less than 200 nm in diameter and had a narrow size distribution. Encapsulation of CoQ10 in liposomes composed of SPC and Vit E significantly (p < 0.05) enhanced its accumulation (at least twofold) in rat skin, compared with an unencapsulated suspension. Prolonging the treatment time and increasing the content of CoQ10 in the formulation both raised the amount of CoQ10 in rat skin. However, in skin treated with the highest CoQ10 content formulation, insufficient treatment time limited the amount accumulated. This study demonstrates that liposomal CoQ10 is a promising candidate for the topical application of CoQ10. The treatment duration is the key factor limiting penetration following in vivo topical application.