Claims for Patent: 9,592,253

Summary for Patent: 9,592,253

Title:	Extended use zirconium silicate compositions and methods of use thereof
Abstract:	The present invention relates to zirconium silicate compositions having a lead content that is below 0.6 ppm and methods of manufacturing zirconium silicate at reactor volumes exceeding 200-L with a lead content below 1.1 ppm. The lead content of the zirconium silicate of this invention are within the levels that are considered acceptable for extended use given the dose requirements for zirconium silicate.
Inventor(s):	Keyser; Donald Jeffrey (Southlake, TX), Guillem; Alvaro F. (Lantana, TX)
Assignee:	ZS PHARMA, INC. (Coppell, TX)
Application Number:	14/883,428
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 9,592,253
Patent Claims:	1. A cation exchange composition manufactured by a process of reacting colloidal silica and zirconium acetate at an agitation rate and time sufficient to disrupt silica bonds, wherein the cation exchange composition comprises a zirconium silicate of formula (I): A.sub.pM.sub.xZr.sub.1-xSi.sub.nGe.sub.yO.sub.m (I) 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 about 0 to about 12, "y" has a value from 0 to about 12, "m" has a value from about 3 to about 36 and 1.ltoreq.n+y.ltoreq.12, wherein the zirconium silicate exhibits a lead content below 0.6 ppm. 2. The composition of claim 1, wherein the lead content ranges from 0.1 to 0.5 ppm. 3. The composition of claim 1, wherein the lead content ranges from 0.3 to 0.5 ppm. 4. The composition of claim 1, wherein the lead content ranges from 0.3 to 0.45 ppm. 5. The composition of claim 1, wherein less than 7% of the particles in the composition have a diameter less than 3 microns. 6. The composition of claim 1, wherein less than 0.5% of the particles in the composition have a diameter less than 1 microns. 7. The composition of claim 1, wherein less than 7% of the particles in the composition have a diameter less than 3 microns, and the sodium content is below 12%. 8. The composition of claim 1, wherein less than 7% of the particles in the composition have a diameter less than 3 microns, and the sodium content is 9% or less. 9. The composition of claim 1, wherein the composition exhibits an XRD diffractogram having the two highest peaks occur at approximately 15.5 and 28.9 degrees 2 theta as obtained from a copper K-alpha radiation source, with the highest peak occurring at 28.9. 10. The composition of claim 1, wherein the pH is from 7 to 9. 11. The composition of claim 1, wherein the potassium loading capacity is between 2.7 and 3.7 mEq/g. 12. The composition of claim 1, wherein the potassium loading capacity is approximately 3.5 mEq/g. 13. A method for treatment of hyperkalemia comprising administering the composition defined in claim 1 to a patient in need thereof. 14. The method of claim 13, wherein the lead content ranges from 0.1 to 0.5 ppm. 15. The method of claim 13, wherein the lead content ranges from 0.3 to 0.5 ppm. 16. The method of claim 13, wherein the lead content ranges from 0.3 to 0.45 ppm. 17. The method of claim 13, wherein less than 7% of the particles in the composition have a diameter less than 3 microns. 18. The method of claim 13, wherein less than 0.5% of the particles in the composition have a diameter less than 1 microns. 19. The method of claim 13, wherein less than 7% of the particles in the composition have a diameter less than 3 microns, and the sodium content is below 12%. 20. The method of claim 13, wherein less than 7% of the particles in the composition have a diameter less than 3 microns, and the sodium content is 9% or less. 21. The method of claim 13, wherein the composition exhibits an XRD diffractogram having the two highest peaks occur at approximately 15.5 and 28.9 degrees 2 theta as obtained from a copper K-alpha radiation source, with the highest peak occurring at 28.9. 22. The method of claim 13, wherein the pH is from 7 to 9. 23. The method of claim 13, wherein the potassium loading capacity is between 2.7 and 3.7 mEq/g. 24. The method of claim 13, wherein the potassium loading capacity is approximately 3.5 mEq/g. 25. The method of claim 13, wherein the administration occurs for more than 5 days. 26. A method of making zirconium silicate of formula (I) comprising: adding colloidal silica to a reactor, the reactor having a volume of at least 200-L, reacting the colloidal silica with zirconium acetate at an agitation rate and time sufficient to disrupt silica bonds thereby forming the zirconium silicate of formula (I); A.sub.pM.sub.xZr.sub.1-xSi.sub.nGe.sub.yO.sub.m (I) 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 about 0 to about 12, "y" has a value from 0 to about 12, "m" has a value from about 3 to about 36 and 1.ltoreq.n+y.ltoreq.12, wherein the zirconium silicate has a lead content of less than 0.6 ppm. 27. The method of claim 26, wherein the lead content ranges from 0.1 to 0.6 ppm. 28. The method of claim 26, wherein the lead content ranges from 0.3 to 0.5 ppm. 29. The method of claim 26, wherein the lead content ranges from 0.3 to 0.45 ppm. 30. The composition of claim 1, wherein the agitation rate and time sufficient to disrupt silica bonds is at least 200 rpm for about 20 minutes.