Formation of Pseudo-Intercellular Lipids Membrane on the Skin Surface by the Alpha-Gel Holding a Large Amount of Water

A new formulation technique for skin care products, an α-gel holding a large amount of water (LW-α-gel) containing pseudo-ceramide, has been developed. LW-α-gel holds a large amount of water between lamellar bilayers and forms a smoothly-extended film on the skin surface after application. Pseudo-ceramide (P-Cer) , fatty alcohol (C16OH) , and monoglycerin derivative (C16GE) were chosen as the α-gel premixture components. When the pseudo-sphingosine (P-Sp) to LW-α-gel premixture (CPP≈1) ratio was greater than 1/25 and neutralized, interplanar spacing of the lamellar structure was dramatically increased and its appearance turned transparent. By using structural analysis, it was confirmed that an almost uniform and highly ordered lamellar structure was maintained in the continuous phase. We observed that the lamellar film formed a layered structure parallel to the skin surface similar to the lamellar structure of intercellular lipids. LW-α-gel can provide extremely high water holding film property when compared to conventional α-gel. Namely, it was proved that specially-designed LW-α-gel can form an intercellular lipid-like lamellar film on skin. LW-α-gel's skin moisturizing efficacy was evaluated. The stratum corneum's continuous water holding property was observed even 6 h after LW-α-gel application. Improvement in transepidermal water loss was observed and P-Cer penetration increased. In the 2-week home use test, significant improvement in dry skin scaling was observed. These results were supported by observations of P-Cer's low melting enthalpy and the lamellar film's water holding property.