Microporous zirconium silicate for the treatment of hyperkalemia
AssigneeZs Pharma, Inc.
InventorsDonald Jeffrey Keyser, Alvaro F. Guillem
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Abstract
The present invention relates to novel microporous zirconium silicate compositions that are formulated to remove toxins, e.g. potassium ions, from the gastrointestinal tract at an elevated rate without causing undesirable side effects. The preferred formulations are designed avoid increase in pH of urine in patients and/or avoid potential entry of particles into the bloodstream of the patient. Also disclosed is a method for preparing high purity crystals of UZSi-9 exhibiting an enhanced level of potassium exchange capacity. These compositions are particularly useful in the therapeutic treatment of hyperkalemia.
Claims22
A particulate pharmaceutical cation exchange composition comprising a zirconium silicate of formula (I):
- ApMxZr1-xSinGeyOm (I)
- in ZS-9 form, where
- A is a potassium ion, sodium ion, rubidium ion, cesium ion, calcium ion, magnesium ion, hydronium ion or mixtures thereof,
- M is at least one framework metal, wherein the framework metal is hafnium (4+), tin (4+), niobium (5+), titanium (4+), cerium (4+), germanium (4+), praseodymium (4+), terbium (4+) or mixtures thereof,
- “p” has a value from about 1 to about 20,
- “x” has a value from 0 to less than 1,
- “n” has a value from 1 to about 12,
- “y” has a value from 0 to about 12,
- “m” has a value from about 3 to about 36 and 1≦n+y≦12,
- wherein the particles exhibit a uniform microporous structure and a median particle size of greater than 3 microns and less than 7% of the particles in the composition have a diameter less than 3 microns, and the composition exhibits a sodium content below 12% by weight.
A powdered pharmaceutical cation exchange composition comprising ZS-9 having an X-ray diffraction pattern generated using a copper K-alpha radiation source of:
- d(Å)
- 5.9-6.7
- 5.3-6.1
- 2.7-3.5
- 2.0-2.8
- 1.6-2.4
- wherein the ZS-9 exhibits a uniform microporous structure and a median particle size of greater than 3 microns and less than 3% of the particles in the composition have a diameter less than 3 microns, and the composition exhibits a sodium content below 12% by weight.
Dependencies are inferred from the claim text.