Buffered compositions for dialysis

Abstract

Dry acid-concentrate compositions comprising citrate and their use in preparing dialysate compositions and in performing hemodialysis is disclosed.

1 . A dry acid-concentrate composition wherein upon mixing the dry acid-concentrate composition with water an aqueous acid-concentrate composition is formed comprising chloride at a concentration of about 1,000 to about 7,000 mEq/L, citrate at a concentration ranging from about 20 to about 900 mEq/L, and physiologically-acceptable cations in an amount sufficient to provide a neutral dialysate composition, wherein the aqueous acid-concentrate composition has a pH of less than 4 and does not contain any of acetate, bicarbonate or lactate. 
     
     
         2 . The dry acid-concentrate of  claim 1  wherein the physiologically-acceptable cation is selected from a group consisting of hydrogen, sodium, potassium, calcium, magnesium, and combinations thereof. 
     
     
         3 . The dry acid-concentrate of  claim 1  wherein upon mixing the dry acid-concentrate composition with water, the chloride is present in a concentration ranging from about 2,000 to about 5,000 mEq/L. 
     
     
         4 . The dry acid-concentrate of  claim 1  wherein upon mixing the dry acid-concentrate composition with water, the citrate is present in a concentration ranging from about 70 to about 150 mEq/L. 
     
     
         5 . A dry acid-concentrate composition comprising a source of chloride, a source of citrate and a source of a physiologically-acceptable cation wherein upon mixing the dry acid-concentrate composition with water an aqueous acid-concentrate composition is formed comprising chloride at a concentration of about 1,000 to about 7,000 mEq/L, citrate at a concentration ranging from about 20 to about 900 mEq/L, and physiologically-acceptable cations in an amount sufficient to provide a neutral dialysate composition when mixed with a base, wherein the aqueous acid-concentrate composition has a pH of less than 4 and does not contain any of acetate, bicarbonate or lactate. 
     
     
         6 . The dry acid-concentrate of  claim 5  wherein the source of citrate is citric acid or a salt thereof selected from a group consisting of sodium dihydrogen citrate, disodium hydrogen citrate, trisodium citrate, trisodium citrate dihydrate, potassium dihydrogen citrate, dipotassium hydrogen citrate, calcium citrate, and magnesium citrate. 
     
     
         7 . The dry acid-concentrate composition of  claim 1  or  claim 5  wherein the dry acid-concentrate is a pellet or a tablet. 
     
     
         8 . The dry acid-concentrate composition of  claim 1  or  claim 5  wherein the dry acid-concentrate is a powder. 
     
     
         9 . A method of preparing a dialysate composition, wherein the method comprising mixing together water, a dry acid-concentrate composition of  claim 1  or  claim 5  and an aqueous bicarbonate-containing solution to form the dialysate composition wherein the dialysate composition has a neutral charge and a physiologically acceptable pH. 
     
     
         10 . A method of performing hemodialysis on a patient wherein the method comprises mixing water, a dry acid-concentrate composition of  claim 1  or  claim 5 , and an aqueous bicarbonate-containing solution to form a dialysate composition wherein the dialysate composition has a neutral charge and a physiologically acceptable pH and using the dialysate composition so formed in a dialyzer in which blood from the patient is circulated.