Buffered compositions for dialysis

Abstract

Acid concentrates, and dialysate compositions prepared therefrom, contain citric acid and an effective amount of a buffering agent selected from acetate and/or lactate. The buffering agent allows a physiologically acceptable amount of citrate to maintain the desired pH of the dialysate.

1 .- 19 . (canceled) 
     
     
         20 . A buffered dialysate composition comprising treated water; chloride at a concentration ranging from 40 to 150 mEq/L; citrate at a concentration ranging from 1.5 to 4.5 mEq/L; a buffering anion selected from acetate, in the form of an acetate salt, and/or lactate, in the form of a lactate salt at a concentration ranging from 0.2 to 0.5 mEq/L; bicarbonate at a concentration ranging from 25 to 45 mEq/L; and at least one physiologically-acceptable cation selected from hydrogen, sodium at a concentration ranging from 60 to 190 mEq/L, potassium at a concentration of less than 5 mEq/L, calcium at a concentration of less than 5 mEq/L, and magnesium at a concentration of less than 2 mEq/L; and glucose at a concentration of less than 45 g/L, wherein the combined composition meets or exceeds the AAMI-quality standard set for dialysate. 
     
     
         21 . The dialysate composition of  claim 20  wherein the water meets or exceeds the purity requirements established by Association for the Advancement of Medical Instrumentation (AAMI) for dialysate and all other components have at least United States Pharmacopeia (USP)-grade purity. 
     
     
         22 . The dialysate composition of  claim 20  or  21  wherein the pH is 5 to 8.5 at a temperature of 25° C. to 40° C. 
     
     
         23 . The dialysate composition of  claim 20  or  21  comprising chloride at a concentration ranging from 60 to 120 mEq/L; citrate at a concentration ranging from 2 to 3 mEq/L; acetate, in the form of an acetate salt, at a concentration ranging from 0.2 to 0.5 mEq/L; bicarbonate at a concentration ranging from 25 to 45 mEq/L; at least one physiologically-acceptable cation selected from hydrogen, sodium at a concentration ranging from 70 to 150 mEq/L, potassium at a concentration of less than 5 mEq/L, calcium at a concentration of less than 5 mEq/L, and magnesium at a concentration of less than 2 mEq/L; and glucose in the form of dextrose at a concentration of less than 8 g/L, where the dialysate composition meets or exceeds the AAMI-quality standard set for dialysate. 
     
     
         24 . A method of forming a buffered dialysate composition comprising mixing a dialysate precursor composition with an aqueous bicarbonate-containing solution, the dialysate precursor composition comprising treated water, chloride, citrate, at least one buffering anion selected from acetate, in the form of an acetate salt, and lactate, in the form of a lactate salt, and at least one physiologically-acceptable cation to provide a dialysate composition having chloride at a concentration ranging from 60 to 120 mEq/L, citrate at a concentration ranging from 1.5 to 4.5 mEq/L, and at least one buffering anion selected from acetate, in the form of an acetate salt, and lactate, in the form of a lactate salt, at a concentration ranging from 0.2 to 0.5 mEq/L; bicarbonate at a concentration ranging from 25 to 45 mEq/L; and at least one physiologically-acceptable cation selected from hydrogen, sodium at a concentration ranging from 60 to 190 mEq/L, potassium at a concentration of less than 5 mEq/L, calcium at a concentration of less than 5 mEq/L, and magnesium at a concentration of less than 2 mEq/L; and glucose at a concentration of less than 45 g/L, wherein the combined composition meets or exceeds the AAMI-quality standard set for dialysate. 
     
     
         25 . The method of  claim 24  wherein the dialysate composition has a final pH from 7.2 to 7.4 at a temperature from 25° C. to 40° C.