A complex between an insulin and a polysaccharide comprising carboxyl functional groups is described, the polysaccharide being chosen from polysaccharides functionalized with at least one phenylalanine derivative, noted Phe, the phenylalanine derivative being chosen from phenylalanine and its alkali metal cation salts, phenylalaninol, phenylalaninamide and ethylbenzylamine or from phenylalanine esters, and the insulin being either a human insulin or an insulin analog. A pharmaceutical composition including at least one complex, especially in the form of an injectable solution, is also described.
