STABILIZING METHOD OF AQUEOUS SOLUTION OF UROCANIC ACID

摘要

PURPOSE:To prepare a stable aqueous solution of urocanic acid usable for a cosmetic having an ultraviolet light absorbing action, by preventing the discoloration of the solution due to the urocanic acid with Na or K salt of tripolyphosphoric acid or tetrapolyphosphoric acid added thereto. CONSTITUTION:An aqueous solution of urocanic acid in an alkali is mixed with 0.01-1.0wt% one or two or more types of sodium and/or potassium salts of tripolyphosphoric acid or tetrapolyphosphoric acid to prevent the discoloration by light, heat, air, etc. with time into yellow brown to give a stable aqueous solution thereof.