PURPOSE: To obtain a skin lightener and a skin cosmetic which have excellent skin-lightening effect and can prevent and treat skin spots and ephelis caused by sun burn by using a specific 1,3-diarylindan-2-carboxylic acid.
CONSTITUTION: A 1,3-diarylindan-2-carboxylic acid of the formula [when R1 is H, 3,4-methylenedioxy or, 4-methoxy; R2 is H, 5-hydroxy or, 5-n-propoxy; R3 is H, 3,4-methylenedioxy, 4-methoxy or, 2-carboxymethoxy) is used. The compound of the formula is formulated to the skin cosmetic preferably in an amount of 0.0001-10wt.%. This skin lightener inhibits the melanin formation in melanocytes to prevent and improve the melanin pigmentation. Further, the formulation of glycyrrhizin, ascorbic acid derivative and the like can increase the melanin pigmentation-suppressing effect. The addition of a variety of UV-ray absorbers also can improve the sun-tan prevention effect.
IMOKAWA GENJI
SUZUKI YASUTO
