TYROSINASE ACTIVITY INHIBITOR AND SKIN EXTERNAL PREPARATION

摘要

PROBLEM TO BE SOLVED: To provide: a tyrosinase activity inhibitor capable of effectively suppressing tyrosinase activity; a cosmetic having excellent skin-whitening effects; and a skin external preparation useful as a quasi drug.SOLUTION: There is provided a tyrosinase activity inhibitor obtained by combining a metal chelate compound of α-lipoylamino acid (provided that the metal is zinc, cobalt or iron) or a pharmacologically acceptable salt thereof (A) and one or two or more ascorbic acids selected from an ascorbic acid, an ascorbic acid glucoside, an ascorbic acid-phosphoric acid monoester and a salt thereof. When the use ratio R is defined as R=[the concentration (μg/mL) of the (A) component/the concentration (mg/mL) of the (B) component], the use ratio R preferably is 0.0001 to 1000. There are provided a skin external preparation and a cosmetic obtained by blending both the components (A) and (B) as an active component for suppressing tyrosinase activity. There is provided a tyrosinase activity inhibitor in which the component (A) is sodium zinc histidine dithiooctanamide.SELECTED DRAWING: None