Disclosed is a pharmaceutical composition for treating hyperuricemia (HUA). The pharmaceutical composition includes a polysaccharide-polyamine copolymer and a pharmaceutically acceptable salt thereof as active ingredients. The polysaccharide-polyamine copolymer is formed by copolymerization of the following two parts: a selectively oxidized polysaccharide with 2,3-dialdehydo, and a polyamine with an amino functional group； the polyamine with an amino functional group and the selectively oxidized polysaccharide with 2,3-dialdehydo can form a net structure by means of covalent crosslinking, resulting in a hydrogel with an amino functional group or a granular polysaccharide-polyamine copolymer, wherein the amino functional group in the hydrogel with an amino functional group or the granular polysaccharide-polyamine copolymer can be protonated so as to form a cationic copolymer of a three-dimensional network structure having a protonated site, and the nitrogen content of the cationic copolymer and the nitrogen content of the polysaccharide-polyamine copolymer are above 12.3 wt %, and both the cationic copolymer and the polysaccharide-polyamine copolymer are water-insoluble.L'invention concerne des copolymères réticulés de manière covalente. Plus spécifiquement, l'invention concerne des matrices ou structures copolymères de polysaccharide-polyamine et des matrices copolymères cationiques. Les copolymères de polysaccharide-polyamine, lorsqu'ils sont protonés, peuvent former des matrices copolymères cationiques ayant des densités exceptionnellement élevées de sites cationiques. Dans un mode de réalisation, les copolymères réticulés de manière covalente forment une structure en trois dimensions, notamment lorsqu'ils sont hydratés.
