Microporous zirconium silicate for the treatment of hyperkalemia

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.

1 - 46 . (canceled) 
     
     
         47 . A microporous zirconium silicate composition made according to a process comprising:
 providing a reaction mixture comprising sodium silicate and zirconium acetate in a reactor;   agitating the reaction mixture with an agitator in the presence of one or more baffle-like structures; and   obtaining the cation exchange composition from the reactor, wherein the presence of the baffle-like structure increases the crystalline purity and potassium exchange capacity of the resulting composition.   
     
     
         48 . The method of  claim 47 , further comprising a step of contacting the zirconium silicate with a dilute solution of strong acid and/or water. 
     
     
         49 . The method of  claim 47 , wherein the composition exhibits a median particles size of greater than 3 microns and less than 7% of the particles in the composition have a diameter less than 3 microns. 
     
     
         50 . The method of  claim 47 , wherein the composition exhibits a sodium content below 12% by weight. 
     
     
         51 . The method of  claim 49 , wherein the median particles size ranges from 5 to 1000 microns. 
     
     
         52 . The method of  claim 51 , wherein the median particles size ranges from 20 to 100 microns. 
     
     
         53 . The method of  claim 49 , wherein the reactor comprises:
 a reaction vessel having a volume of at least 20-L and an inside and outside wall;   an agitator within the reaction vessel;   a cooling jacket proximate the outside wall of the reaction vessel;   at least one baffle-like structure proximate the inside wall of the reaction vessel and placed in operative proximity to the agitator to provide a uniform suspension of solids within the reaction vessel.   
     
     
         54 . The method of  claim 53 , wherein the reaction vessel has a volume in the range of 200-L or greater. 
     
     
         55 . The method of  claim 47 , wherein the FTIR spectra of the composition does not include absorption peaks at approximately 764 and 955 cm -1 . 
     
     
         56 . The method of  claim 47 , wherein the XRD plot of the composition does not indicate significant peaks at 2-theta values of 7.5, 32, or 42.5.