Process of forming iron hydroxypyrone compounds

Abstract

The invention provides a method of forming an iron hydroxypyrone compound comprising reacting a hydroxypyrone with a non-carboxylate iron salt in an aqueous solution, and precipitating the iron hydroxypyrone compound from the aqueous solution having a pH of greater than 7.

1 - 23 . (canceled) 
     
     
         24 . A pharmaceutical composition comprising an iron hydroxypyrone compound and an iron hydroxide. 
     
     
         25 . The composition according to  claim 24 , wherein the iron hydroxide is present in an amount of less than 3 wt. %. 
     
     
         26 . The composition according to  claim 24 , wherein the iron hydroxide is present in an amount of from 0.01 to 3 wt. %. 
     
     
         27 . The composition according to  claim 24 , wherein the iron hydroxide comprises ferric hydroxide or Fe(OH) 3 . 
     
     
         28 . The composition according to  claim 24 , wherein the iron hydroxide is non-therapeutic, inert, or pharmaceutically inactive and in the form of a solid. 
     
     
         29 . The composition according to  claim 24 , wherein the iron hydroxide is a pharmaceutically acceptable excipient. 
     
     
         30 . The composition according to  claim 24 , wherein the iron hydroxide provides the composition with a stable color. 
     
     
         31 . The composition according to  claim 24 , wherein the composition further comprises a hydroxypyrone compound, such as maltol, ethyl maltol and mixtures thereof. 
     
     
         32 . The composition according to  claim 24 , wherein the composition is in the form of a solid. 
     
     
         33 . The composition according to  claim 32 , wherein the solid is a powder, capsule or tablet. 
     
     
         34 . The composition according to  claim 24 , wherein the iron hydroxide is present in the composition in an amount of less than 10 wt. % based on the weight of the composition, such as from 0.01 to 2 wt. %. 
     
     
         35 . The composition according to  claim 24 , wherein the iron hydroxypyrone comprises ferric trimaltol. 
     
     
         36 . The composition according to  claim 24 , wherein the iron hydroxide does not comprise colloidal iron hydroxide or a sugar protected form of an iron hydroxide. 
     
     
         37 . The composition according to  claim 24 , wherein the iron hydroxypyrone is present in the composition in an amount of at least 40 wt. %. 
     
     
         38 . A pharmaceutical composition in the form of a solid comprising ferric trimaltol in an amount of at least 40 wt. % and a non-therapeutic solid ferric hydroxide in an amount of less than 10 wt. %, and wherein the composition does not substantially change color when exposed to ambient conditions of temperature and humidity.