Metal compounds, mixed or sulphated, as phosphate binders
A non-aluminum containing mixed metal compound for pharmaceutical use, which may, for example, be a mixed metal hydroxy carbonate containing magnesium and iron, and may have a hydrotalcite structure, preferably a non-aged hydrotalcite structure. Other metals, including, for example, calcium, lanthanum and cerium, may also be used. Metal sulphate compounds, especially calcium sulphate, lanthanum sulphate and/or cerium sulphate, compounds are also useful. The mixed metal compounds have a phosphate binding capacity of at least 30%, by weight, based on the test methods 1, 2 or 3, described in the specification, over a pH range from 3 to 7, such as from 2 to 8. The compound is especially useful in the treatment of hyperphosphataemia.
1. A method for treating hyperphosphataemia, in an animal in need thereof, which comprises administering to said animal, a therapeutically effective amount of a solid mixed metal compound having a phosphate binding capacity, and comprising the compound obtained as a precipitate from a solution of a mixture of metallic salts, free from aluminum, and containing iron (III) and at least one additional metal selected from the group consisting of magnesium, calcium, lanthanum and cerium, said compound having a phosphate binding capacity of at least 30%, as measured by any of the following tests methods (1) or (2), over a pH range of from 3 to 7;
(1) adding 1 gram of said solid mixed metal compound to 25 ml of 40 mmol 1 −1 sodium phosphate buffer solution, homogenizing and gently agitating at room temperature of 30 minutes, centrifuging at 3000 rpm for 5 minutes, filtering through 0.22 μm millipore filter and measuring the soluble phosphate in the supernatant thus produced;
(2) adding 1 gram of said solid mixed metal compound to 25 ml of 20 mmol 1 −1 sodium phosphate buffer solution, homogenizing and gently agitating at room temperature for 30 minutes, centrifuging at 3000 rpm for 5 minutes, filtering through 0.22 μm millipore filter and measuring the soluble phosphate 1 the supernatant thus produced.
2. Method according to claim 1 wherein the solid mixed metal compound containing hydroxyl ions and/or carbonate ions.
3. Method according to claim 2 , wherein the solid mixed metal compound further contains sulphate, chloride, oxide or mixtures thereof.
4. The method of claim 1 wherein said animal is a human.
5. A method for treating hyperphosphataemia, in an animal in need thereof, which comprises administering to said animal, a therapeutically effective amount of a solid mixed metal oxide compound having phosphate binding capacity, and comprising the compound obtained as a precipitate from a solution of a mixture of metallic salts, free from aluminum, and containing iron (III) and at least one additional metal selected from the group consisting of magnesium, calcium, lanthanum and cerium, said compound having a phosphate binding capacity of at least 30%, as measured by any of the following test methods (1) or (2), over a pH range of from 2 to 8;
(1) adding 1 gram of said solid mixed metal compound to 25 ml of 40 mmol 1 −1 sodium phosphate buffer solution, homogenizing and gently agitating at room temperature of 30 minutes centrifuging at 3000 rpm for 5 minutes, filtering through 0.22 μm millipore filter and measuring the soluble phosphate in the supernatant thus produced;
(2) adding 1 gram of said solid mixed metal compound to 25 ml of 20 mmol 1 −1 sodium phosphate buffer solution, homogenizing and gently agitating at room temperature for 30 minutes, centrifuging at 3000 rpm for 5 minutes, filtering through 0.22 μm millipore filter and measuring the soluble phosphate in the supernatant thus produced.
6. Method according to claim 5 , wherein the solid mixed metal compound contains hydroxyl ions and/or carbonate ions.
7. Method according to claim 6 , wherein the solid mixed metal compound further contains sulphate, chloride, oxide or mixture thereof.
8. The method of claim 5 wherein said animal is a human.
9. A method for treating hyperphosphataemia, in an animal in need thereof, which comprises administering to said animal, a therapeutically effective amount of a solid mixed metal compound having phosphate binding capacity, and comprising a hydroxy carbonate containing iron (III) and magnesium metals, further containing sulphate, chloride, oxide or mixtures thereof and free from aluminum, and having a phosphate binding capacity of at least 30% by weight, as measured by any of the test methods (1) or (2), over a pH range of 2 to 8;
(1) adding 1 gram of said solid mixed metal compound to 25 ml of 40 mmol 1 −1 sodium phosphate buffer solution, homogenizing and gently agitating at room temperature of 30 minutes, centrifuging at 3000 rpm for 5 minutes, filtering through 0.22 μm millipore filter and measuring the soluble phosphate in the supernatant thus produced;
(2) adding 1 gram of said solid mixed metal compound to 25 ml of 20 mmol 1 −1 sodium phosphate buffer solution, homogenizing and gently agitating at room temperature for 30 minutes, centrifuging at 3000 rpm for 5 minutes, filtering through 0.22 μm millipore filter and measuring the soluble phosphate in the supernatant thus produced.
10. The method of claim 9 wherein said animal is a human.