Process for the selective elimination of inorganic phosphate from liquids by means of adsorbent materials modified with polynuclear metal oxyhydroxiders and production of the adsorbent materials

Process for the production of a pharmaceutical agent for oral administration for the selective removal of inorganic phosphate from an aqueous solution containing protein comprising:

• impregnating an adsorbent base material with a solution or a suspension of an iron salt which is convertible into a polynuclear iron (III) oxyhydroxide to form an impregnated adsorbent base material;
• and
• causing the pH of said impregnated adsorbent base material to be at least about 10 sufficient to convert said iron salt to a polynuclear iron (III) oxyhydroxide and to thereby form a composition of an adsorbent base material having a layer consisting essentially of polynuclear iron (III) oxyhydroxide disposed thereon, without conducting any step of separating said impregnated adsorbent base material from said solution or suspension between said impregnating and said causing the pH of said impregnated adsorbent base material to be at least about 10;
• whereby externally binding said polynuclear iron (III) oxyhydroxide to a surface of said adsorbent base material to produce an aqueous insoluble adsorbent composition;
• wherein, upon being contacted with an aqueous liquid containing inorganic phosphate ions and protein, said aqueous insoluble adsorbent composition is:
• sufficiently adsorptively reactive with said phosphate ions in said aqueous liquid to adsorb phosphate ions thereon;
• and
• not sufficiently adsorptively reactive with said protein in said aqueous liquid to extract protein from said aqueous liquid nor to adsorb protein from said aqueous liquid.