Iron derivatives of modified milk protein.

A product containing a high amount of iron and maintaining all the necessary characteristics of stability and solubility for a drug can be prepared by succinylating the proteins, in the specific case the milk proteins, before the reaction with the iron salt. For these derivatives a particular advantage can be achieved, the iron succinyl protein precipitates at the pH of the stomach further keeping the iron bonded and it re-solubilizes at pH higher than 7, the intestine pH level. Electrophoresis indicates that the iron succinyl protein is homogeneous and gel filtration shows an apparent high molecular weight that contributes to the stability of the complexed iron. The preliminary structure determined by analytical and physical-chemical methods indicates that iron, in the form of oligomeric complexes, is tightly bonded to the protein not in chelated structures with basic residues but involving several sites of the protein chain. The solubility of the iron complex is assured by the increased availability of carboxyl groups that follows the succinylation reaction.