Abstract

Purpose: The effect of the concentration of sodium chondroitin sulfate (ChS-Na) in a mixed solution with sodium hyaluronate on skin moisturization following a single application (2 and 4 h) was evaluated in rats and human volunteers. A mixed solution (MS) of ChS-Na with sodium hyaluronate (HA-Na) and the marketed formulation consisting of these two compounds (ZZ: CC® Adsorb Essence: ZZ: CC®) were also evaluated for skin moisturization following repeated application (9–14 d). Methods: MS consisted of different concentrations of ChS-Na and a fixed concentration of HA-Na solution or ZZ: CC® were used as the test compounds. The test compounds were applied to the abdominal skin surface of hairless rats and the ventral forearms of human volunteers as single and repeated applications to measure skin conductance. The skin moisturization exhibited by human volunteers after repeated application was also visually monitored by morphological methods. Results: The hygroscopic or water-holding capacity of hairless rat skin or human skin after a single application of MS was higher than that of distilled water. MS at a ChS-Na and HA-Na concentration of 0.5% and 0.015%, respectively, produced the highest value among the different concentrations of MS. The hygroscopic and water-holding capacity of the ventral forearms of human volunteers following repeated application of ZZ: CC® was significantly higher than in the untreated group. Conclusion: These results suggest that ChS-Na and HA-Na, after single and repeated application, improve skin dryness and skin moisturization, and the mixed formulation will be useful for skin care.

Keywords:  Sodium chondroitin sulfate   Sodium hyaluronate   Skin moisturization   Hairless rat   Human volunteer