REMOVAL OF PHOSPHATE FROM DILUTE PHOSPHATE SOLUTION BY AN IRON CHITOSAN COMPLEX TO BE USED AS AN ORAL SORBENT

The long-period administration of aluminum-containing phosphate binders for the treatment of hyperphosphatemia has been shown to carry the risk of aluminum accumulation associated with many bone diseases. An iron chitosan complex prepared by chitosan and iron(II) sulfate was examined as an alternative intestinal phosphate binder. In-vitro experiments have shown that the phosphate-binding capacity of iron chitosan increases with increasing the iron content of iron chitosan, the concentration of phosphate, and the pH of the solution. The phosphate-binding capacity of iron chitosan (iron content 32 mg g-1) was over 30 mg g-1 when 10 mg of iron chitosan was admitted to 10 ml of a phosphate solution of 10 mg dl-1 (pH 7.5) at 37-degrees-C for 6 h. This value is much higher than those of aluminum hydroxide, calcium carbonate, etc., which were practically tried before. No elution of the iron from iron chitosan could be detected under these conditions.