α‐Lipoic acid is amphipathic with low molecular sulphur‐containing fatty acid and has strong antioxidant effects. It has been used at the purposes of anti‐ageing, treatment of diabetic neuropathy, and supplement as antioxidant. Though α‐lipoic acid is normally administered in oral or injection, it has not been used in a topical use via skin because of its bad penetration. We developed the novel nanocapsule of α‐lipoic acid, named α‐lipoactive (nLA), to improve skin permeability. The nLA is constructed as micelles of α‐lipoic acid mixed with the non‐ionic surfactant, and its surface of the micelles was coated with inorganic metal salts. It is water soluble and has a diameter of approximately 8‐15 nm. After nLA was applied to the murine skin, epidermal thickening was observed. It was confirmed that this effect is caused by α‐lipoic acid molecule, but not by the raw material used for encapsulation. In in vivo experiments, it was found that nLA is very effective for improving UV‐induced pigmentation and epidermal thickening. Our findings suggest that nanoencapsulation of α‐lipoic acid is considerably effective for topical application.

No abstract

Studies have shown that liquid crystals structurally resembling the intercellular lipids in the stratum corneum can beneficially affect the skin when applied topically by stimulating the skin's natural regenerative functions and accelerating epidermal turnover. In the present study, the effects of applying low concentrations of a liquid crystal gel of our own creation were evaluated using epidermal thickening in mouse skin as an assay for effective stimulation of epidermal turnover. A liquid crystal gel was also applied topically to human facial skin, and analysis was conducted using before-and-after photographs of age spots, measurements of L* values that reflect degree of skin pigmentation, single-layer samples of the stratum corneum obtained via tape-stripping, and measurements of trans-epidermal water loss that reflect the status of the skin's barrier function. The results suggested that cost-effective creams containing as low as 5% liquid crystal gel might be effective and safely sold as skin care products targeting age spots and other problems relating to uneven skin pigmentation.

A novel emulsion and its preparation route were established in a quasi-ternary system with a nonionic surfactant, water, glycerol, and squalane. This emulsion is simply obtained by diluting a discontinuous cubic liquid crystal. It consists of giant floc in part, corresponding to the fraction of the discontinuous cubic liquid crystal. Contrary to common emulsification, our emulsion has an unique and abnormal shear-response: the semistable structure is breaking down gradually by applying a mechanical energy.

No abstract