Complex between human insulin and an amphiphilic polymer and use of this complex in the preparation of a fast-acting human insulin formulation

A complex between human insulin and an amphiphilic polymer comprising carboxyl functional groups, said amphiphilic polymer being chosen from functionalized polysaccharides predominantly composed of glycoside monomers bonded via glycoside bonds of (1,6) type which are functionalized by at least one tryptophan derivative, which polysaccharides are chosen from the polysaccharides of formula I:

• in which:
• F resulting from the coupling between the connecting arm R and an —OH function of the polysaccharide and being either an ester, thionoester, amide, carbonate, carbamate, ether, thioether or amine function,
• R being a chain comprising between 1 and 6 carbons, optionally branched and/or unsaturated, comprising one or more heteroatoms, and/or S, and having at least one carboxyl function,
• Trp being a residue of an L or D tryptophan derivative, the product of the coupling between the amine of the tryptophan derivative and at least one acid carried by the R group and/or one acid carried by the polysaccharide comprising carboxyl functional groups,
• n represents the molar fraction of the R groups substituted by Trp and is between 0.05 and 0.7,
• i represents the molar fraction of the F-R-[Trp]n groups carried per saccharide unit and is between 0 and 2,
• and, when R is not substituted by Trp, then the acid or acids of the R group are carboxylates of a cation said polysaccharides being amphiphilic at neutral pH.