Iron preparation suitable for pharmaceutical formulation and process for the preparation thereof
New iron preparations comprising stable, unpolymerized iron(III) citrate complex compositions and methods for their preparation are provided. Further, the invention involves the use stable, unpolymerized iron(III) citrate complex compositions of the invention as a food additive, nutritional supplement, dietary supplement, medical food, nutrient, iron fortificant, and source of iron in the fields of nutrition for humans, animals, fish, and birds and of diagnostics. The invention further involves the use of stable, unpolymerized iron(III) citrate complex compositions of the invention as a pharmaceutical and pharmacologically active ingredient for human clinical and veterinary applications.
1. A stable, water-soluble, unpolymerized ferric citrate chelate composition, having, by weight, from about 9% to about 14% iron, from about 30% to about 60% citrate, from about 5% to about 20% pyrophosphate, and from about 1% to about 15% sodium, wherein said composition is essentially free of sulfate.
2. The composition of claim 1 , wherein said composition has a molar ratio of Fe 3+ to pyrophosphate of from about 2:1 to 5:1 and a citrate:pyrophosphate ratio of from about 2:1 to 5:1.
3. The composition of claim 1 , wherein said composition has a molar ratio of Fe 3+ to pyrophosphate of from about 1.8:1 to 2.2:1 and a citrate:pyrophosphate ratio of from about 1.8:1 to 2.2:1.
4. The composition of claim 2 , wherein 1 gram of said composition dissolves essentially to completion in 10 ml of water in about 15 minutes.
5. The composition of claim 2 , wherein 1 gram of said composition dissolves essentially to completion in 10 ml water after adjustment of pH to about 5.
6. The composition of claim 1 , wherein an aqueous solution containing 5 weight percent of said composition has a pH of from about 2 to 3.
7. The composition of claim 1 , wherein said composition is essentially free of ammonia.
8. A method of preparing a stable, water-soluble, unpolymerized ferric citrate chelate composition comprising combining ferrous citrate dibasic and disodium dihydrogen pyrophosphate in water, exposing the resulting mixture to oxygen in a volume sufficient to oxidize the ferrous iron to ferric iron and at a rate sufficiently slow to allow complex formation between iron(III), citrate, and pyrophosphate as oxidation occurs, and isolating a stable, unpolymerized iron(III) citrate complex by removing water therefrom.
9. The method of claim 8 wherein oxygen is added as a gas containing from about 5% to about 25% oxygen.
10. A method of administering iron to a subject in need of such administration for the prevention or treatment of iron-deficiency or anemia comprising administering a therapeutic quantity of a stable, water-soluble, unpolymerized ferric citrate chelate composition, having, by weight, from about 9% to about 14% iron, from about 30% to about 60% citrate, from about 5% to about 20% pyrophosphate, and from about 1% to about 15% sodium, wherein said composition is essentially free of sulfate.
11. The method of administering of claim 10 wherein said administering is oral or intravenous.
12. The method of claim 10 wherein the therapeutic quantity of a stable, water-soluble, unpolymerized ferric citrate chelate composition is administered together with therapeutic quantities of ingredients selected from the group consisting of a pharmaceutically acceptable form of L-ascorbate, a pharmaceutically acceptable form of folic acid, a pharmaceutically acceptable form of vitamin B12, and a pharmaceutically acceptable form of biotin.
13. A method of administering iron to a chemical or biological system having a deficiency in iron comprising administering a quantity of a stable, water-soluble, unpolymerized ferric citrate chelate composition sufficient to correct the deficiency in iron in the system, wherein said composition has, by weight, from about 9% to about 14% iron, from about 30% to about 60% citrate, from about 5% to about 20% pyrophosphate, and from about 1% to about 15% sodium, wherein said composition is essentially free of sulfate.