Anhydrous silver dihydrogen citrate compositions

Abstract

Anhydrous silver dihydrogen citrate compositions comprise silver dihydrogen citrate and citric acid. The anhydrous compositions can be prepared by freeze-drying. The anhydrous compositions can be reconstituted with a suitable diluent to form silver dihydrogen citrate compositions. The anhydrous compositions can be reconstituted and applied to a variety of substrates to impart an antimicrobial effect on the substrates.

1 . A composition comprising anhydrous silver dihydrogen citrate and citric acid.  
   
   
       2 . The anhydrous composition of  claim 1 , wherein the composition is substantially free of water.  
   
   
       3 . The anhydrous composition of  claim 1 , wherein the composition contains less than about 0.5% water.  
   
   
       4 . The anhydrous composition of  claim 1 , wherein the composition is crystalline.  
   
   
       5 . The anhydrous composition of  claim 1 , wherein the composition comprises a molar excess of citric acid over silver dihydrogen citrate.  
   
   
       6 . The anhydrous composition of  claim 1 , wherein the composition comprises at least a 5 fold molar excess of citric acid over silver dihydrogen citrate.  
   
   
       7 . A process of making a composition comprising an anhydrous silver dihydrogen citrate and citric acid, comprising the steps of: 
 (a) providing a stock solution comprising silver dihydrogen citrate, citric acid and water;    (b) freezing the stock solution to form a frozen solution; and    (c) freeze-drying the frozen solution to form the anhydrous composition.    
   
   
       8 . The process of  claim 7 , wherein the citric acid is a molar excess of citric acid over silver dihydrogen citrate.  
   
   
       9 . The process of  claim 7 , wherein step (c) further comprises heating the frozen solution.  
   
   
       10 . A method of using an anhydrous silver dihydrogen citrate and citric acid composition, comprising combining the anhydrous silver dihydrogen citrate composition with an amount of aqueous diluent sufficient to produce a reconstituted antimicrobially active silver dihydrogen citrate composition.  
   
   
       11 . The method of  claim 10 , wherein the aqueous diluent is substantially pure water.  
   
   
       12 . The method of  claim 10 , wherein the aqueous diluent comprises water and at least one member of the group consisting of alcohols and detergents.  
   
   
       13 . A method of using an anhydrous silver dihydrogen citrate and citric acid composition, comprising combining the anhydrous silver dihydrogen citrate composition with sufficient aqueous diluent to produce an antimicrobially effective silver dihydrogen citrate solution; and applying the antimicrobially effective silver dihydrogen citrate solution to a substrate, whereby an antimicrobial effect is achieved.  
   
   
       14 . The method of  claim 13 , wherein the substrate is a solid surface, a food article or a non-food article.  
   
   
       15 . The method of  claim 14 , wherein the solid surface is the interior of a pipe, a holding tank, a swimming pool, a spa, a cooling system or a cooling tower.  
   
   
       16 . The method of  claim 13 , wherein the antimicrobial effect is biocidal or biofilm control.  
   
   
       17 . The method of  claim 13 , wherein the antimicrobial effect is food preservation.