Sodium bicarbonate containing precipitate-free dialysis solutions

• US 5,211,643 A
• Filed: 05/25/1990
• Issued: 05/18/1993
• Est. Priority Date: 05/26/1989
• Status: Expired due to Term

• Current Assignee: Fresenius AG (Fresenius SE & Co. KGaA)
• Original Assignee: Fresenius AG (Fresenius SE & Co. KGaA)
• Inventors: Reinhardt, Bertold, Bartz, Volker
• Primary Examiner(s): Rosenbaum, C. Fred
• Assistant Examiner(s): STRIGHT, RONALD K
• Application Number:
  US07/528,855
• Time in Patent Office: 1,089 Days
• Field of Search: 604/403, 604/410, 604/411, 604/416, 604/5, 206/219, 206/221, 206/438, 206/484, 206/524.1, 206/524.2, 206/524.6, 424/686, 424/687, 514/974
• US Class Current: 604/416
• CPC Class Codes: A61M 1/287 Dialysates therefor

Abstract

Dialysis solutions for hemodialysis and the like, are prepared by addition of sufficient acid to lower the pH of a sodium carbonate solution to less than 7.6 under conditions which will retain the carbon dioxide generated by such acid addition and mixing the thus produced solution with a solution of the other ions required in such a dialysis solution, again under conditions which will retain the carbon dioxide, to provide a dialysis solution which, under working conditions, will not cause finely divided precipitates of calcium carbonate to form.

Claims

1. A delivery system for the delivery of sodium bicarbonate containing fluids for dialysis and the like, comprising:

a) a container having at least one means of egress for liquid, containing an aqueous solution comprising at least sodium bicarbonate of between 25 and 40 meq/l. of bicarbonate ion at pH below 7.6;

said container having a water vapor permeability of less than 1 g/m² /day/bar as measured by DIN 53122 and a carbon dioxide permeability of less than 1 cm³ /100 μ

m/m² /day/bar at 20°

C. as measured by DIN 53380;

b) a container having at least one means of ingress for liquid and at least one means of egress for liquid containing an aqueous solution comprising between 0.1 and 10 meq./l. of Ca²⁺, 0 to 6 meg./l. Mg²⁺, 90.5 to 121 meq./l. Cl^-, 180-290 meq./l. Na⁺ ;

wherein the egress means of (a) is connected to the ingress means of (b).

2. A delivery system in accordance with claim 1, wherein the amount of sodium bicarbonate content is sufficient to bring the hydrogen carbonate content of the mixed fluid in both chambers to at least 20 mmol.

3. A delivery system in accordance with claim 2, wherein the hydrogen carbonate content of the mixed fluid in both chambers contains 25 to 40 mmol of bicarbonate.

4. A delivery system in accordance with claim 3, wherein the sodium bicarbonate solution has a pH of 7.2 to 7.4.

5. A delivery system of claim 1, wherein the container is:

a) an outer bag structure of organic polymer having at least two chambers,

b) a first of said chambers filled with said bicarbonate containing solution,

c) a second of said chambers filled with said solution of other ions,

d) an openable flow blocking valve connecting said first with said second chamber, said valve being the sole ingress or egress means to said second chamber, and

e) at least one discharge tube fitted with a removable closure, said discharge tube passing through and being sealed to said outer bag and into a said first chamber.

6. A delivery system of claim 1, wherein the pH value is adjusted by a physiologically acceptable acid.

7. A delivery system of claim 6, wherein the acid is hydrochloric acid.

8. A delivery system of claim 6, wherein the acid is carbonic acid.

9. A method of producing a dialysis solution which comprises:

a) adding a physiologically acceptable acid to an aqueous solution of sodium bicarbonate having an original pH exceeding 8 to reduce the pH thereof to less than 7.6;

b) sterilizing the said solution under conditions which will retain the carbon dioxide generated by said acid addition therein;

c) preparing a basic solution containing all of the other ions required to form said dialysis solution;

d) sterilizing said basic solution;

e) mixing said bicarbonate solution and said basic solution under conditions which will retain the carbon dioxide generated by the acid added to said bicarbonate solution.

10. Sodium bicarbonate-containing aqueous concentrate, which is substantially free from calcium ion, for mixing with a second calcium ion-containing concentrate, which is substantially free of bicarbonate ion, for the production of a dialysis fluid suitable for hemo or peritoneal dialysis containing the following composition in mval per liter:

Ca²⁺ =0.5-5

Mg²⁺ =0-3

Cl^- =90.5-121

Na⁺ =128-145

K⁺ =0-4

HCO₃ =25-40

characterized thereby that the sodium bicarbonate-containing aqueous concentrate, prior to mixing with said calcium ion-containing concentrate, has added thereto a sufficient amount of physiologically acceptable acid to bring the pH value of said bicarbonate-containing aqueous concentrate below 7.6 and is held in a container which is substantially impermeable to water vapor and carbon dioxide.

11. Sodium bicarbonate-containing aqueous concentrate in accordance with claim 10 characterized thereby that the pH value lies in the physiological range of 7.2 to 7.4.

12. Sodium bicarbonate-containing aqueous concentrate in accordance with claim 10 characterized thereby that the pH value is adjusted by hydrochloric acid.