POLY-ALPHA-AMINO ACID PARTICLE

摘要

PROBLEM TO BE SOLVED: To obtain poly-α-amino acid particles lightened in a property of irritating the skin without detriment to ultraviolet absorptivity and having improved biocompatibility by incorporating a polymer containing an ultraviolet absorber in a poly-α-amino acid particle. SOLUTION: Five (5) to 500 pts.wt. ultraviolet-absorbing polymer obtained by copolymerizing an ultraviolet absorber having a radical-polymerizable double bond with a radical-polymerizable monomer in a weight ratio of 5/95 to 100/0 is incorporated in 100 pts.wt. poly-α-amino acid particle (by, for example, a method comprising polymerizing anα-amino acid N-carbonic anhydride in the presence of seeds comprising an ultraviolet absorbing polymer obtained by radical polymerization to form core/shell structure poly-α-amino acid particles). The obtained particles desirably have a mean particle diameter of 0.01-100μm and a variation coefficient of the mean particle diameter of 1-30%.