| 摘要 |
PROBLEM TO BE SOLVED: To provide an ultraviolet absorber having a high water solubility, an excellent absorptivity over a wide ultraviolet wavelength region, no absorptions in the visible region, and having high stability and safety by using a pyrimidine derivative or its salt as the principal component. SOLUTION: This absorber consists mainly of a pyrimidine derivative of formula I or its salt. In the formula, R1 is H or a 1-3C alkyl; A is a group of any one of formulae II, III, and IV; and R2 is H, a 1-3C H or an alkyl. Although the absorber can be incorporated in various products, it is desirable to incorporate it in an external dermatologic preparation. An external dermatologic preparation containing this absorber exhibits an excellent ultraviolet intercepting effect, is excellent in product stability because of no tendency to suffer from the deposition of the constituent ultraviolet absorber even when stored at low temperatures, and exhibits its effect stably for a long time because the absorber does not decompose even upon exposure to sunlight.
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