COMPOSITIONS AND METHODS FOR REGENERATING CARRIER PROTEIN-CONTAINING MULTIPLE PASS ALBUMIN DIALYSIS FLUID

Abstract

The present invention provides compositions which can be used to treat a carrier protein-containing multiple pass dialysis fluid in particular in order to ensure regeneration of a carrier protein such as albumin in the dialysis fluid. The invention further relates to kits comprising such compositions and uses thereof as well as to methods for providing and regenerating a carrier protein-containing multiple pass dialysis fluid.

Claims

1. A kit for treating a carrier protein-containing multiple pass dialysis fluid comprising (a) an acidic composition comprising a biologically compatible acid, and (b) an alkaline composition comprising a biologically compatible base, wherein the ratio of the concentration of the biologically compatible acid in the acidic composition (a) to the concentration of the biologically compatible base in the alkaline composition (b) is in the range from 0.7 to 1.3, preferably in the range from 0.75 to 1.25 and more preferably in the range from 0.8 to 1.2 and wherein the concentration of the biologically compatible acid in the acidic composition and the concentration of the biologically compatible base in the alkaline composition is at least 50 mmol/l and no more than 500 mmol/l.

2. The kit according to claim 1, wherein the concentration of the biologically compatible acid in the acidic composition (a) and the concentration of the biologically compatible base in the alkaline composition (b) is at least 60 mmol and no more than 400 mmol/l, preferably at least 70 mmol/l and no more than 300 mmol/l and more preferably at least 100 mmol/l and no more than 200 mmol/l.

3. The kit according to claim 1, wherein the acidic composition (a) is an aqueous solution of the biologically compatible acid, optionally comprising further components, and wherein the alkaline composition (b) is an aqueous solution of the biologically compatible base, optionally comprising further components.

4. The kit according to claim 1, wherein the kit comprises a stabilizer for a carrier protein, in particular a stabilizer for albumin.

5. The kit according to claim 4, wherein the kit comprises (c1) a stabilizer composition comprising the stabilizer for a carrier protein, in particular the stabilizer for albumin, wherein the stabilizer composition (c1) is different from the acidic composition (a) and from the alkaline composition (b).

6. The kit according to claim 4, wherein the stabilizer for a carrier protein, in particular the stabilizer for albumin, is selected from the group consisting of amino acids, salts of amino acids, derivatives of amino acids, fatty acids, salts of fatty acids, derivatives of fatty acids, sugars, polyols and osmolytes.

7. The kit according to claim 6, wherein the stabilizer is selected from the group consisting of fatty acids, salts of fatty acids and derivatives of fatty acids.

8. The kit according to claim 7, wherein the stabilizer is selected from the group consisting of caprylate, caprylic acid, caprate, capric acid, caproic acid and caproate, preferably the stabilizer is a caprylate.

9. The kit according to claim 5, wherein the concentration of the stabilizer in the stabilizer composition (c1) is in the range from 1 to 2500 mmol/l, more preferably from 50 to 1500 mmol/l, even more preferably from 100 to 1000 mmol/l and most preferably from 150 to 500 mmol/l.

10. The kit according to claim 1, wherein the kit further comprises (c2) a nutrient composition comprising a nutrient, in particular a sugar, wherein the nutrient composition (c2) is different from the acidic composition (a) and from the alkaline composition (b).

11. The kit according to claim 10, wherein the nutrient is glucose.

12. The kit according to claim 1, wherein the kit comprises at least one component selected from the group consisting of sodium, chloride, calcium, magnesium, potassium, phosphate and carbonate/bicarbonate.

13. The kit according to claim 12, wherein at least one component selected from the group consisting of sodium, chloride, calcium, magnesium, potassium and phosphate is comprised by the acidic composition (a).

14. The kit according to claim 12, wherein at least one component selected from the group consisting of sodium, chloride, potassium, phosphate, carbonate/bicarbonate and Tris is comprised by the alkaline composition (b).

15. The kit according to claim 12, wherein the kit further comprises (c3) an electrolyte composition comprising at least one component selected from the group consisting of sodium, chloride, calcium, magnesium, potassium and phosphate, wherein the electrolyte composition (c3) is different from the acidic composition (a) and from the alkaline composition (b).

16. The kit according to claim 12, wherein the source of sodium is NaOH, Na.sub.2CO.sub.3, Na.sub.2HPO.sub.4, NaHCO.sub.3, NaCl, and/or a sodium salt of lactate, acetate, gluconate, citrate, maleate, tartrate and/or of fatty acids such as caprylate.

17. The kit according to claim 12, wherein the source of chloride is HCl, NaCl, KCl, MgCl.sub.2, and/or CaCl.sub.2.

18. The kit according to claim 12, wherein the source of potassium is KOH and/or KCl.

19. The kit according to claim 12, wherein the source of calcium is CaCl.sub.2, CaCO.sub.3, and/or a calcium salt of lactate, acetate, gluconate, citrate, maleate, tartrate and/or of fatty acids, preferably the source of calcium is a calcium salt of lactate, acetate, gluconate, citrate, maleate and/or tartrate.

20. The kit according to claim 12, wherein the source of magnesium is MgCl.sub.2, MgCO.sub.3, and/or a magnesium salt of lactate, acetate, gluconate, citrate, maleate, tartrate and/or of fatty acids, preferably the source of magnesium is a magnesium salt of lactate, acetate, gluconate, citrate, maleate and/or tartrate.

21. The kit according to claim 12, wherein the kit further comprises (c4) a buffering composition comprising a buffering agent, in particular carbonate/bicarbonate, wherein the buffering composition (c4) is different from the acidic composition (a) and from the alkaline composition (b).

22. The kit according to claim 5, wherein the kit comprises a stabilizer composition (c1) and a nutrient composition (c2) and wherein the stabilizer composition (c1) and the nutrient composition (c2) are the same composition (c5) or different compositions.

23. The kit according to claim 15, wherein the kit comprises an electrolyte composition (c3) and a buffering composition (c4) and wherein the electrolyte composition (c3) and the buffering composition (c4) are the same composition (c6) or different compositions.

24. The kit according to claim 5, wherein the kit comprises a stabilizer composition (c1) and an electrolyte composition (c3) and wherein the stabilizer composition (c1) and the electrolyte composition (c3) are the same composition (c7) or different compositions.

25. The kit according to claim 10, wherein the kit comprises a nutrient composition (c2) and an electrolyte composition (c3) and wherein the nutrient composition (c2) and the electrolyte composition (c3) are the same composition (c8) or different compositions.

26. The kit according to claim 5, wherein the kit comprises a stabilizer composition (c1) and a buffering composition (c4) and wherein the stabilizer composition (c1) and the buffering composition (c4) are the same composition (c9) or different compositions.

27. The kit according to claim 10, wherein the kit comprises a nutrient composition (c2) and a buffering composition (c4) and wherein the nutrient composition (c2) and the buffering composition (c4) are the same composition (c10) or different compositions.

28. The kit according to claim 5, wherein the kit comprises a stabilizer composition (c1), a nutrient composition (c2) and an electrolyte composition (c3) and wherein the stabilizer composition (c1), the nutrient composition (c2) and the electrolyte composition (c3) are the same composition (c11) or different compositions.

29. The kit according to claim 5, wherein the kit comprises a stabilizer composition (c1), a nutrient composition (c2), an electrolyte composition (c3) and a buffering composition (c4) and wherein the stabilizer composition (c1), the nutrient composition (c2), the electrolyte composition (c3) and the buffering composition (c4) are the same composition (c12) or different compositions.

30. The kit according to claim 1, wherein (a) the acidic composition (a) comprises at least one component selected from the group consisting of sodium, chloride, calcium, magnesium, potassium and phosphate; and (b) the alkaline composition (b) comprises at least one component selected from the group consisting of sodium, chloride, potassium, phosphate and carbonate/bicarbonate and, optionally, a stabilizer for a carrier protein, in particular a stabilizer for albumin.

31. The kit according to claim 1, wherein (a) the acidic composition (a) comprises at least one component selected from the group consisting of sodium, chloride, calcium, magnesium, potassium and phosphate; and (b) the alkaline composition (b) comprises at least one component selected from the group consisting of sodium, chloride, potassium, phosphate and carbonate/bicarbonate; and wherein the kit further comprises a stabilizer composition (c1) comprising a stabilizer for a carrier protein, in particular a stabilizer for albumin, wherein the stabilizer composition (c1) is different from the acidic composition (a) and from the alkaline composition (b); and/or a nutrient composition (c2) comprising a nutrient, in particular a sugar, wherein the nutrient composition (c2) is different from the acidic composition (a) and from the alkaline composition (b).

32. The kit according to claim 31, wherein the kit comprises a stabilizer/nutrient composition (c5), which comprises a sugar, preferably glucose, and a stabilizer for a carrier protein, in particular a stabilizer for albumin, preferably a caprylate, wherein the composition (c5) is different from the acidic composition (a) and from the alkaline composition (b).

33. The kit according to claim 32, wherein the kit comprises a stabilizer/nutrient/electrolyte composition (c11), which comprises a sugar, preferably glucose, a stabilizer for a carrier protein, in particular a stabilizer for albumin, preferably caprylate, and at least one component selected from the group consisting of sodium, chloride, calcium, magnesium, potassium and phosphate; and wherein the composition (c11) is different from the acidic composition (a) and from the alkaline composition (b).

34. Use of a kit according to claim 1 for treating, in particular regenerating, a carrier protein-containing multiple pass dialysis fluid.

35. A method for regenerating a carrier protein-containing multiple pass dialysis fluid, wherein the carrier protein-containing multiple pass dialysis fluid is treated, in particular regenerated, with an acidic composition (a), which comprises a biologically compatible acid, and with an alkaline composition (b), which comprises a biologically compatible base, wherein the ratio of the concentration of the biologically compatible acid in the acidic composition (a) to the concentration of the biologically compatible base in the alkaline composition (b) is in the range from 0.7 to 1.3, preferably in the range from 0.75 to 1.25 and more preferably in the range from 0.8 to 1.2 and wherein the concentration of the biologically compatible acid in the acidic composition and the concentration of the biologically compatible base in the alkaline composition is at least 50 mmol/l and no more than 500 mmol/l.

36. The method according to claim 35, wherein the treatment of the carrier protein-containing multiple pass dialysis fluid with the acidic composition (a) and with the alkaline composition (b) occurs consecutively.

37. The method according to claim 35 comprising the following steps: (i) passing the carrier protein-containing multiple pass dialysis fluid through a dialyzer, (ii) dividing the flow of the carrier protein-containing multiple pass dialysis fluid into a first flow and a second flow, (iii) adding the acidic composition (a) to the first flow of the carrier protein-containing multiple pass dialysis fluid and the alkaline composition (b) to the second flow of the carrier protein-containing multiple pass dialysis fluid, (iv) filtration of the first flow of the carrier protein-containing multiple pass dialysis fluid treated with the acidic composition (a) and of the second flow of the carrier protein-containing multiple pass dialysis fluid treated with the alkaline composition (b), (v) rejoining the first flow of the carrier protein-containing multiple pass dialysis fluid treated with the acidic composition (a) and the second flow of the carrier protein-containing multiple pass dialysis fluid treated with the alkaline composition (b), and (vi) optionally, performing a further cycle beginning with step (i).

38. The method according to claim 37, wherein in step (iii) the addition of the acidic composition (a) to the first flow of the carrier protein-containing multiple pass dialysis fluid occurs at about the same time as the addition of the alkaline composition (b) to the second flow of the carrier protein-containing multiple pass dialysis fluid.

39. The method according to claim 35, wherein the carrier protein-containing multiple pass dialysis fluid is treated with a stabilizer composition (c1), which comprises a stabilizer for a carrier protein, in particular a stabilizer for albumin, and which is different from the acidic composition (a) and from the alkaline composition (b).

40. The method according to claim 35, wherein the carrier protein-containing multiple pass dialysis fluid is treated with a nutrient composition (c2), which comprises a nutrient, in particular a sugar, and which is different from the acidic composition (a) and from the alkaline composition (b).

41. The method Method according to claim 35, wherein the carrier protein-containing multiple pass dialysis fluid is treated with an electrolyte composition (c3), which comprises at least one component selected from the group consisting of sodium, chloride, calcium, magnesium, potassium and phosphate and which is different from the acidic composition (a) and from the alkaline composition (b).

42. The method according to claim 35, wherein the carrier protein-containing multiple pass dialysis fluid is treated with a buffering composition (c4), which comprises a buffering agent, in particular carbonate/bicarbonate, and which is different from the acidic composition (a) and from the alkaline composition (b).

43. The method according to claim 35, wherein the carrier protein-containing multiple pass dialysis fluid is treated with a stabilizer composition (c1), a nutrient composition (c2) and/or an electrolyte composition (c3) and wherein the stabilizer composition (c1), the nutrient composition (c2) and/or the electrolyte composition (c3) are the same composition or different compositions.

44. The method according to claim 35, wherein the carrier protein-containing multiple pass dialysis fluid is treated with a stabilizer composition (c1), a nutrient composition (c2), an electrolyte composition (c3) and/or buffering composition (c4) and wherein the stabilizer composition (c1), the nutrient composition (c2), the electrolyte composition (c3) and/or the buffering composition (c4) are the same composition or different compositions.

45. The method according to claim 44, wherein the stabilizer composition (c1), the nutrient composition (c2), the electrolyte composition (c3) and/or the buffering composition (c4) are added to the carrier protein-containing multiple pass dialysis fluid after the treatment of the carrier protein-containing multiple pass dialysis fluid with the acidic composition (a) and with the alkaline composition (b), preferably after step (v) of claim 37, and before passing the carrier protein-containing multiple pass dialysis fluid through the dialyzer.

46. The method according to claim 37 comprising a step (v-1) following upon step (v) and preceding step (vi): (v-1) adding to the carrier protein-containing multiple pass dialysis fluid: (i) a stabilizer composition (c1), which comprises a stabilizer for a carrier protein, in particular a stabilizer for albumin; (ii) a nutrient composition (c2), which comprises a nutrient, in particular a sugar; (iii) an electrolyte composition (c3), which comprises at least one component selected from the group consisting of sodium, chloride, calcium, magnesium, potassium and phosphate and/or (iv) a buffering composition (c4), which comprises a buffering agent, in particular carbonate/bicarbonate; wherein the stabilizer composition (c1), the nutrient composition (c2), the electrolyte composition (c3) and/or the buffering composition (c4) are the same composition or different compositions.

47. A method for providing a carrier protein-containing multiple pass dialysis fluid comprising the following steps: (i) providing an acidic composition (a), which comprises a biologically compatible acid, and an alkaline composition (b), which comprises a biologically compatible base, wherein the ratio of the concentration of the biologically compatible acid in the acidic composition (a) to the concentration of the biologically compatible base in the alkaline composition (b) is in the range from 0.7 to 1.3, preferably in the range from 0.75 to 1.25 and more preferably in the range from 0.8 to 1.2 and wherein the concentration of the biologically compatible acid in the acidic composition (a) and the concentration of the biologically compatible base in the alkaline composition (b) is at least 50 mmol/l and no more than 500 mmol/l, (ii) merging the acidic composition (a) with the alkaline composition (b), and (iii) adding a carrier protein, preferably albumin, more preferably human serum albumin (HSA).

48. The method according to claim 47 comprising a step (ii-1) following upon step (ii) and preceding step (iii): (ii-1) adding (i) a stabilizer composition (c1), which comprises a stabilizer for a carrier protein, in particular a stabilizer for albumin; (ii) a nutrient composition (c2), which comprises a sugar; (iii) an electrolyte composition (c3), which comprises at least one component selected from the group consisting of sodium, chloride, calcium, magnesium, potassium and phosphate and/or (iv) a buffering composition (c4), which comprises a buffering agent, in particular carbonate/bicarbonate, wherein the stabilizer composition (c1), the nutrient composition (c2), the electrolyte composition (c3) and/or the buffering composition (c4) are the same composition or different compositions.

49. Use of a kit according to claim 1 in a method according to claim 35.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0228] In the following a brief description of the appended figures will be given. The figures are intended to illustrate the present invention in more detail. However, they are not intended to limit the subject matter of the invention in any way.

[0229] FIG. 1 shows a schematic representation of an exemplified dialysis system, which is preferably used for a method for regenerating a carrier protein-containing multiple-pass dialysis fluid according to the present invention.

[0230] FIG. 2 shows for Example 3 the detoxification, i.e. the removal of bilirubin (A) and urea (B) from blood achieved with Kit H as described in Example 1 in a method as described in Example 2.

[0231] FIG. 3 shows for Example 3 the variation of the pH value of the dialysis fluid (A) as well as the pH value of the blood (B). The thick vertical lines on each graph indicate the change of steps during the experiment (i.e. experimental manipulation of the pH value of the dialysis fluid).

[0232] FIG. 4 shows for Example 3 the concentration of sodium in the blood and in the dialysis fluid. The vertical lines on the graph indicate the change of pH value in the dialysate during the experiment as indicated and as described in Example 3.

[0233] FIG. 5 shows for Example 3 the concentration of potassium in the blood and in the dialysis fluid. The vertical lines on the graph indicate the change of pH value in the dialysate during the experiment as indicated and as described in Example 3.

[0234] FIG. 6 shows for Example 3 the concentration of magnesium in the blood and in the dialysis fluid. The vertical lines on the graph indicate the change of pH value in the dialysate during the experiment as indicated and as described in Example 3.

[0235] FIG. 7 shows for Example 3 the concentration of calcium in the blood and in the dialysis fluid. The vertical lines on the graph indicate the change of pH value in the dialysate during the experiment as indicated and as described in Example 3.

[0236] FIG. 8 shows for Example 3 the concentration of chloride in the blood and in the dialysis fluid. The vertical lines on the graph indicate the change of pH value in the dialysate during the experiment as indicated and as described in Example 3.

[0237] FIG. 9 shows for Example 3 the concentration of phosphate in the blood and in the dialysis fluid. The vertical lines on the graph indicate the change of pH value in the dialysate during the experiment as indicated and as described in Example 3.

[0238] FIG. 10 shows for Example 4 the effect of different calcium concentrations, namely, 1.90 mmol/l, 2.06 mmol/l, 2.20 mmol/l, 2.32 mmol/l, 2.48 mmol/l, 2.72 mmol/l and 2.88 mmol/l, in composition (a) for treating a carrier protein-containing multiple pass dialysis fluid at pH 9 (of the dialysis fluid) on the calcium concentration in the blood.

[0239] FIG. 11 shows for Example 5 the copper concentration in pmol/l in blood during a dialysis using a kit according to the present invention.

[0240] FIG. 12 shows schematically for Example 6 the different steps of the simulation model for measuring turbidity.

[0241] FIG. 13 shows for Example 8 the concentration of bilirubin in the blood during a dialysis using kits according to the present invention having different concentrations of a protein stabilizer, namely caprylate.

[0242] FIG. 14 shows for Example 9 the concentration of 5-(Hydroxymethyl)-2-furaldehyd (HMF), which derives from dehydration of sugar and, thus, indicates the stability of glucose. (A) Stability of a composition comprising glucose, but no caprylate, at different temperatures as indicated. (B) Stability of a composition

EXAMPLES

[0243] In the following, particular examples illustrating various embodiments and aspects of the invention are presented. However, the present invention shall not to be limited in scope by the specific embodiments described herein. The following preparations and examples are given to enable those skilled in the art to more clearly understand and to practice the present invention. The present invention, however, is not limited in scope by the exemplified embodiments, which are intended as illustrations of single aspects of the invention only, and methods which are functionally equivalent are within the scope of the invention. Indeed, various modifications of the invention in addition to those described herein will become readily apparent to those skilled in the art from the foregoing description, accompanying figures and the examples below. All such modifications fall within the scope of the appended claims.

Example 1

Examples of Various Kits According to the First Aspect of the Present Invention

[0244] In the following preferred exemplified kits according to the first aspect of the present invention are described. In the following kits, the provided compositions of the exemplified kits, in particular the acidic composition (a), the alkaline composition (b) and, optionally, further compositions as described, can be directly used for providing and/or treating a carrier protein-containing multiple pass dialysis fluid. In other words, in a method according to the present invention the provided compositions of the exemplified kits, in particular the acidic composition (a), the alkaline composition (b) and, optionally, further compositions as described, are directly added (undiluted). In particular, no further composition is required for regeneration and/or provision of the carrier protein-containing multiple pass dialysis fluid.

[0245] Kit A

[0246] The acidic composition (a) comprising a biologically compatible acid is an aqueous solution with the following components:

TABLE-US-00001 HCl 185.0 mmol/l CaCl.sub.2 2H.sub.2O 3.2 mmol/l MgCl.sub.2 6H.sub.2O 1.4 mmol/l Glucose 300.0 mg/dl

[0247] The alkaline composition (b) comprising a biologically compatible base is an aqueous solution with the following components:

TABLE-US-00002 NaOH 195.0 mmol/l Na.sub.2HPO.sub.4 2H.sub.2O 1.0 mmol/l KCl 6.0 mmol/l Na-caprylate (C.sub.8H.sub.15O.sub.2Na) 300.0 mg/dl

[0248] Kit B

[0249] The acidic composition (a) comprising a biologically compatible acid is an aqueous solution with the following components:

TABLE-US-00003 HCl 110.0 mmol/l NaCl 110.0 mmol/l

[0250] The alkaline composition (b) comprising a biologically compatible base is an aqueous solution with the following components:

TABLE-US-00004 NaOH 135.0 mmol/l Na.sub.2HPO.sub.4 2H.sub.2O 1.0 mmol/l KCl 6.0 mmol/l Na-caprylate (C.sub.8H.sub.15O.sub.2Na) 5.0 mmol/l

[0251] Kit C

[0252] The acidic composition (a) comprising a biologically compatible acid is an aqueous solution with the following components:

TABLE-US-00005 HCl 110.0 mmol/l NaCl 90.0 mmol/l

[0253] The alkaline composition (b) comprising a biologically compatible base is an aqueous solution with the following components:

TABLE-US-00006 NaOH 135.0 mmol/l Na.sub.2HPO.sub.4 2H.sub.2O 1.0 mmol/l KCl 6.0 mmol/l Na-caprylate (C.sub.8H.sub.15O.sub.2Na) 1.25 mmol/l

[0254] Kit D

[0255] The acidic composition (a) comprising a biologically compatible acid is an aqueous solution with the following components:

TABLE-US-00007 HCl 164.0 mmol/l NaCl 12.0 mmol/l KCl 7.6 mmol/l Na.sub.2HPO.sub.4 2H.sub.2O 1.0 mmol/l MgCl.sub.2 6H.sub.2O 1.0 mmol/l CaCl.sub.2 2H.sub.2O 1.9 mmol/l

[0256] The alkaline composition (b) comprising a biologically compatible base is an aqueous solution with the following components:

TABLE-US-00008 NaOH 160.0 mmol/l Na.sub.2CO.sub.3 54.0 mmol/l

[0257] Preferably, kit D comprises, in addition to the acidic composition (a) and to the alkaline composition (b), the a stabilizer/electrolyte composition (c7) with the following component: Na-caprylate (C.sub.8H.sub.15O.sub.2Na) 240 mmol/l

[0258] More preferably, kit D comprises, in addition to the acidic composition (a) and to the alkaline composition (b), a stabilizer/electrolyte/nutrient composition (c11) with the following components:

TABLE-US-00009 Na-caprylate (C.sub.8H.sub.15O.sub.2Na) 240 mmol/l Glucose 40 w/w %

[0259] Kit E

[0260] The acidic composition (a) comprising a biologically compatible acid is an aqueous solution with the following components:

TABLE-US-00010 HCl 184.0 mmol/l KCl 7.6 mmol/l Na.sub.2HPO.sub.4 2H.sub.2O 1.0 mmol/l MgCl.sub.2 6H.sub.2O 1.0 mmol/l CaCl.sub.2 2H.sub.2O 2.88 mmol/l

[0261] The alkaline composition (b) comprising a biologically compatible base is an aqueous solution with the following components:

TABLE-US-00011 NaOH 176.0 mmol/l Na.sub.2CO.sub.3 51.8 mmol/l

[0262] Preferably, kit E comprises, in addition to the acidic composition (a) and to the alkaline composition (b), a stabilizer/electrolyte composition (c7) with the following component: Na-caprylate (C.sub.8H.sub.15O.sub.2Na) 240 mmol/l

[0263] More preferably, kit E comprises, in addition to the acidic composition (a) and to the alkaline composition (b), a stabilizer/electrolyte/nutrient composition (c11) with the following components:

TABLE-US-00012 Na-caprylate (C.sub.8H.sub.15O.sub.2Na) 240 mmol/l Glucose 40 w/w %

[0264] Kit F

[0265] The acidic composition (a) comprising a biologically compatible acid is an aqueous solution with the following components:

TABLE-US-00013 HCl 164.0 mmol/l NaCl 12.0 mmol/l KCl 7.6 mmol/l Na.sub.2HPO.sub.4 2H.sub.2O 1.0 mmol/l MgCl.sub.2 6H.sub.2O 1.0 mmol/l CaCl.sub.2 2H.sub.2O 1.9 mmol/l

[0266] The alkaline composition (b) comprising a biologically compatible base is an aqueous solution with the following components:

TABLE-US-00014 NaOH 160.0 mmol/l Na.sub.2CO.sub.3 54.0 mmol/l KOH 10.0 mmol/l

[0267] Preferably, kit F comprises, in addition to the acidic composition (a) and to the alkaline composition (b), a stabilizer/electrolyte composition (c7) with the following component: Na-caprylate (C.sub.8H.sub.15O.sub.2Na) 240 mmol/l

[0268] More preferably, kit F comprises, in addition to the acidic composition (a) and to the alkaline composition (b), a stabilizer/electrolyte/nutrient composition (c11) with the following components:

TABLE-US-00015 Na-caprylate (C.sub.8H.sub.15O.sub.2Na) 240 mmol/l Glucose 40 w/w %

[0269] Kit G

[0270] The acidic composition (a) comprising a biologically compatible acid is an aqueous solution with the following components:

TABLE-US-00016 HCl 164.0 mmol/l NaCl 12.0 mmol/l KCl 7.6 mmol/l Na.sub.2HPO.sub.4 2H.sub.2O 1.0 mmol/l MgCl.sub.2 6H.sub.2O 1.0 mmol/l

[0271] The alkaline composition (b) comprising a biologically compatible base is an aqueous solution with the following components:

TABLE-US-00017 NaOH 160.0 mmol/l Na.sub.2CO.sub.3 54.0 mmol/l KOH 10.0 mmol/l

[0272] Preferably, kit G comprises, in addition to the acidic composition (a) and to the alkaline composition (b), a stabilizer/electrolyte composition (c7) with the following component: Na-caprylate (C.sub.8H.sub.15O.sub.2Na) 240 mmol/l

[0273] More preferably, kit G comprises, in addition to the acidic composition (a) and to the alkaline composition (b), a stabilizer/electrolyte/nutrient composition (c11) with the following components:

TABLE-US-00018 Na-caprylate (C.sub.8H.sub.15O.sub.2Na) 240 mmol/l Glucose 40 w/w %

[0274] Kit H

[0275] The acidic composition (a) comprising a biologically compatible acid is an aqueous solution with the following components:

TABLE-US-00019 HCl 184.0 mmol/l NaCl 6.0 mmol/l Na.sub.2HPO.sub.4 2H.sub.2O 1.0 mmol/l MgCl.sub.2 6H.sub.2O 1.0 mmol/l Na.sub.3 citrate 0.8 mmol/l CaCl.sub.2 2H.sub.2O 2.88 mmol/l

[0276] The alkaline composition (b) comprising a biologically compatible base is an aqueous solution with the following components:

TABLE-US-00020 NaOH 168.4 mmol/l Na.sub.2CO.sub.3 51.8 mmol/l KOH 7.6 mmol/l

[0277] Preferably, kit H comprises, in addition to the acidic composition (a) and to the alkaline composition (b), a stabilizer/electrolyte composition (c7) with the following component:

TABLE-US-00021 Na-caprylate (C.sub.8H.sub.15O.sub.2Na) 240 mmol/l

[0278] More preferably, kit H comprises, in addition to the acidic composition (a) and to the alkaline composition (b), a stabilizer/electrolyte/nutrient composition (c11) with the following components:

TABLE-US-00022 Na-caprylate (C.sub.8H.sub.15O.sub.2Na) 240 mmol/l Glucose 40 w/w %

[0279] Each of the above kits A-H can be used to obtain/regenerate a carrier protein-containing multiple pass dialysis fluid having a pH from 6.5 to 10, in particular from 7.45 to 9. Kits B and C, which do not comprise calcium, magnesium and bicarbonate, can even be used to obtain/regenerate a carrier protein-containing multiple pass dialysis fluid having a pH from 6.35 to 11.4.

Comparative ExampleKit I

[0280] The acidic composition (a) comprising a biologically compatible acid is an aqueous solution with the following components:

TABLE-US-00023 HCl 100.0 mmol/l NaCl 12.0 mmol/l KCl 7.6 mmol/l Na.sub.2HPO.sub.4 2H.sub.2O 1.0 mmol/l

[0281] The alkaline composition (b) comprising a biologically compatible base is an aqueous solution with the following components:

TABLE-US-00024 NaOH 160.0 mmol/l NaCl 68.0 mmol/l

[0282] Kit I differs from kits A-H primarily in that the ratio of the concentration of the biologically compatible acid in the acidic composition (a) to the concentration of the biologically compatible base in the alkaline composition (b) is 0.625, whereas that ratio is in the range of 0.7 to 1.3 for kits A-H. The carrier protein-containing multiple pass dialysis fluid obtained/regenerated by kit I has a pH>10, whereas with kits A-H the pH of the dialysis fluid can be adjusted to values from 6.5 to 10, in particular from 7.45 to 9.

Example 2

Method for Regenerating a Carrier Protein-Containing Multiple-Pass Dialysis Fluid

[0283] FIG. 1 shows a diagrammatic representation of an exemplified dialysis system, which is preferably used for a method for regenerating a carrier protein-containing multiple-pass dialysis fluid according to the present invention. The dialysis system is described in more detail in WO 2009/071103 A1, which is incorporated herein by reference.

[0284] Blood from the patient is transported through the tubings via a blood pump (22). Before it is returned to the patient, the blood is passed through two dialyzers (8) which contain the semipermeable membranes. In said dialyzers the blood is separated from the dialysis fluid by means of the semipermeable membranes. Dilution fluids, namely, predilution (5) and postdilution fluids (6) can be optionally added to the patient's blood via the predilution pump (21) and the postdilution pump (23). Blood flow rates are, in general, between 50-2000 ml/min, typically depending on the type and duration of dialysis. Preferably, blood flow rates are between 150-600 ml/min and more preferably between 250-400 ml/min. Predilution flow rates are preferably between 1-10 l/h and more preferably 4-7 l/h. Postdilution flow rates are preferably between 5-30% of the chosen blood flow rates and more preferably between 15-20%.

[0285] The dialysis fluid is pumped into the dialysate compartment of the dialyzers with a pump (16) from the dialysis fluid reservoir (7) at a flow rate between 50-4000 ml/min, preferably between 150-2000 ml/min, more preferably between 500-1100 ml/min and most preferably at about 800 ml/min. The dialysis fluid with the optionally added predilution and postdilution and other fluids taken from the patient to reduce his volume overload are transported back to the dialysis fluid reservoir (7) via a pump (24) at flow rates depending on the flow rates of the predilution, postdilution and the dialysate and the amount of fluid that should be removed from the patient.

[0286] In general, the dialysis fluid is cleaned continuously or intermittently by (i) manipulation of the pH and temperature as well as (ii) optically, by irradiating with waves, light, electrical and/or magnetic fields, in combination with addition of further components, such as a stabilizer, a nutrient, a buffer and/or an electrolyte and filtration. After passing through the dialyzer (8) and through the dialysis fluid reservoir (7), the flow of the carrier protein-containing multiple pass dialysis fluid, which contains for example toxins, is split into a first flow and a second flow. The regeneration pumps (18, 19) transport the first flow of the carrier protein-containing multiple pass dialysis fluid and the second flow of the carrier protein-containing multiple pass dialysis fluid through the tubings from and to the dialysis fluid reservoir (7). The pump on the acid side (18) and the pump on the base side (19) transport the dialysis fluid downstream to one of two filters (9, 10) present in the dialysate regeneration circuit (27) through a valve mechanism (25, 26).

[0287] The acidic composition (a), which is stored and/or mixed in a container (1), is added to the first flow of the carrier protein-containing multiple pass dialysis fluid at the acid side via a pump (17). The alkaline composition (b), which is stored and/or mixed in a container (2), is added to the the second flow of the carrier protein-containing multiple pass dialysis fluid at the base side via a pump (20). Addition of the acidic composition (a)as well as addition of the alkaline composition (b)results in a release of the carrier protein-bound toxins from the carrier protein, such as albumin.

[0288] The valves (25,26) enable (i) that the first flow of the carrier protein-containing multiple pass dialysis fluid treated with the acidic composition (a) is transported either towards the filter (9) or towards the filter (10) (valve 25) and (ii) that the second flow of the carrier protein-containing multiple pass dialysis fluid treated with the alkaline composition (b) is transported either towards the filter (9) or towards the filter (10) (valve 26). The valves (25, 26) may change the direction of flow for example every 5 min-1 hour, preferably every 10 min, so that each filter (9, 10) receives fluid from one pump (1 8 or 19) at a time.

[0289] The first flow of the carrier protein-containing multiple pass dialysis fluid treated with the acidic composition (a) and the second flow of the carrier protein-containing multiple pass dialysis fluid treated with the alkaline composition (b) are filtered in filters (9, 10), thereby removing the toxins and cleaning the carrier protein-containing multiple pass dialysis fluid, and fluids are removed from each filter (9, 10) using two filtrate pumps (13, 14). After filtration, the first flow of the carrier protein-containing multiple pass dialysis fluid treated with the acidic composition (a) is rejoined with the second flow of the carrier protein-containing multiple pass dialysis fluid treated with the alkaline composition (b), thereby mixing the first and the second flow.

[0290] Optionally, after rejoining the first and the second flow of the carrier protein-containing multiple pass dialysis fluid, a stabilizer composition, a nutrient composition, a buffer composition and/or an electrolyte composition is added thereto. For example, the stabilizer composition, the nutrient composition, the buffer composition and/or the electrolyte composition can be stored and/or diluted in the containers (3, 4) and added to the carrier protein-containing multiple pass dialysis fluid via one or two pumps (11, 15). In more general, the stabilizer composition, the nutrient composition, the buffer composition and/or the electrolyte composition can be preferably added to the dialysis fluid at any of positions I to X shown in FIG. 1.

Example 3

Test of Kit H in a Method as Described in Example 2

[0291] Kit H as described in Example 1 was tested in a method as described in Example 2 in order to evaluate detoxification and electrolyte content in blood and dialysis fluid at different pH values and flow rates of the dialysis fluid.

[0292] To this end, a total of six experiments were performed using porcine blood and two dialysis devices LK2001 (Hepa Wash GmbH, Munich, Germany). The values shown were measured in blood and dialysate, respectively, just before the blood (or the dialysate) entered into the dialyzer. Results are expressed as average of the data of the six experiments.

[0293] In order to assess different pH values and flow rates the steps shown in Table 1 below were performed:

TABLE-US-00025 TABLE 1 Duration (hh:mm) Tested parameters 00:00 to 01:20 Flow of compostion (a): 160 ml/min Flow of compostion (b): 160 ml/min Dialysate pH: 7.45 01:20 to 02:40 Flow of compostion (a): 160 ml/min Flow of compostion (b): 160 ml/min Dialysate pH: 9/CO.sub.2 4.8 mmol/min 02:40 to 04:00 Flow of compostion (a): 80 ml/min Flow of compostion (b): 80 ml/min Dialysate pH: 7.45 04:00 to 05:20 Flow of compostion (a): 80 ml/min Flow of compostion (b): 80 ml/min Dialysate pH: 9/CO.sub.2 4.8 mmol/min

[0294] FIG. 2 shows the detoxification (blood bilirubin and urea) achieved in this study. As can be retrieved from FIG. 2, urea levels decrease from more than 20 mmol/l to almost 0 mmol/l (FIG. 2B) and bilirubin levels decrease from almost 30 mg/dl to about 11 mg/dl (FIG. 2A).

[0295] FIG. 3 shows the variation of the pH value of the dialysis fluid (A) as well as the pH value of the blood (B). The thick vertical lines on each graph indicate the change of steps during the experiment as described above (i.e. experimental manipulation of the pH value of the dialysis fluid). As shown in FIG. 3B, the blood pH is raising between 01:20 and 02:40 and between 04:00 and at the end due to the applied dialysate pH of 9 and the adjusted buffering capacity of the dialysate fluid. To simulate a acidosis in the blood, CO.sub.2 was administered to the blood and a dialysate pH of 9 was applied, since acidosis is treated by a dialysis liquid with a pH of 9.

[0296] FIG. 4 shows the variation of the sodium concentration in the blood and in the dialysis fluid. The sodium concentrations in the blood are within the physiological limitations of 125-142 mmol/l during the whole treatment. An elevation of the sodium concentration was noted at pH 9.

[0297] FIG. 5 shows the variation of the potassium concentration in the blood and in the dialysis fluid. The potassium concentrations in the blood are within the physiological limitations of 3.4-4.5 mmol/l. There are no significant changes between dialysate-pH 7.45 and dialysate-pH 9. The first potassium value in the blood is at the border of the range since porcine blood usually shows a high concentration of potassium at the very beginning of the measurement. The dialysate values are also within their limitations of 0-5.0 mmol/l.

[0298] FIG. 6 shows the variation of the magnesium concentration in the blood and in the dialysis fluid. The magnesium concentrations in the blood are within the physiological limitations of 0.5-1.3 mmol/l during the whole treatment. The dialysate values are also within their limitations.

[0299] FIG. 7 shows the variation of the calcium concentration in the blood and in the dialysis fluid. The calcium concentrations in the blood are within the physiological limitations of 1.0-1.7 mmol/l during the whole treatment. The dialysate pH of 9 is causing a decrease in the calcium concentration. The dialysate values are also within their limitations.

[0300] FIG. 8 shows the variation of the chloride concentration in the blood and in the dialysis fluid. The chloride concentrations in the blood are within the physiological limitations of 95-110 mmol/l during the whole treatment. The dialysate values are also within their limitations.

[0301] FIG. 9 shows the variation of the phosphate concentration in the blood and in the dialysis fluid. The phosphate concentrations in the blood are within the physiological limitations of 0.5-2 mmol/l during the whole treatment. The dialysate values are also within their limitations.

[0302] Taken together, all measured blood concentrations of the electrolytes are within their physiological limitations and the detoxification of the blood was observed. Accordingly, Kit H is useful at varying pH values of the dialysis fluid (7.45 and 9) and at different flow rates of the dialysis fluid.

Example 4

Influence of the Dialysate pH on the Calcium Concentration in the Blood

[0303] As shown in Example 3 (FIG. 7), the increased dialysate pH of 9 is causing a decrease in the calcium concentration of the blood. Calcium is present in ionized, protein-bound and complex-like type. The higher the pH value of the dialysate, the more free calcium of the dialysis fluid binds to the carrier protein, such as albumin, comprised by the dialysis fluid. The decreased concentration of ionized calcium in the dialysis fluid triggers a diffusion of free calcium from blood to the dialysate, which causes decreased calcium levels in the patient.

[0304] Therefore, the influence of the dialysate pH on the calcium concentration in the blood was further investigated in order to provide a kit, which ensures a physiological calcium level in the blood despite treatment with varying pH values of the dialysate.

[0305] To this end, experiments were performed using porcine blood and the dialysis device LK2001 (Hepa Wash GmbH, Munich, Germany). In this experiment, the following kits, which differed only in the concentration of CaCl.sub.2, were used:

[0306] Kit 4A The acidic composition (a) comprising a biologically compatible acid is an aqueous solution with the following components:

TABLE-US-00026 HCl 164.0 mmol/l NaCl 12.0 mmol/l KCl 7.6 mmol/l Na.sub.2HPO.sub.4 2H.sub.2O 1.0 mmol/l MgCl.sub.2 6H.sub.2O 1.0 mmol/l CaCl.sub.2 2H.sub.2O 1.9 mmol/l pH 1.05

[0307] The alkaline composition (b) comprising a biologically compatible base is an aqueous solution with the following components:

TABLE-US-00027 NaOH 160.0 mmol/l Na.sub.2CO.sub.3 54.0 mmol/l pH 12.6

[0308] Kit 4B

[0309] In kit 4B exactly the same components as in kit 4A were used, except that the concentration of CaCl.sub.2 was 2.06 mmol/l instead of 1.9 mmol/l. Accordingly, kit 4B differed only in the concentration of CaCl.sub.2 from kit 4A.

[0310] Kit 4C

[0311] In kit 4C exactly the same components as in kit 4A were used, except that the concentration of CaCl.sub.2 was 2.2 mmol/l instead of 1.9 mmol/l. Accordingly, kit 4C differed only in the concentration of CaCl.sub.2 from kit 4A.

[0312] Kit 4D

[0313] In kit 4D exactly the same components as in kit 4A were used, except that the concentration of CaCl.sub.2 was 2.32 mmol/l instead of 1.9 mmol/l. Accordingly, kit 4D differed only in the concentration of CaCl.sub.2 from kit 4A.

[0314] Kit 4E

[0315] In kit 4E exactly the same components as in kit 4A were used, except that the concentration of CaCl.sub.2 was 2.48 mmol/l instead of 1.9 mmol/l. Accordingly, kit 4E differed only in the concentration of CaCl.sub.2 from kit 4A.

[0316] Kit 4F

[0317] In kit 4F exactly the same components as in kit 4A were used, except that the concentration of CaCl.sub.2 was 2.72 mmol/l instead of 1.9 mmol/l. Accordingly, kit 4F differed only in the concentration of CaCl.sub.2 from kit 4A.

[0318] Kit 4G

[0319] In kit 4G exactly the same components as in kit 4A were used, except that the concentration of CaCl.sub.2 was 2.88 instead of 1.9 mmol/l. Accordingly, kit 4G differed only in the concentration of CaCl.sub.2 from kit 4A.

[0320] The acidic composition (a) and the alkaline composition (b) of those kits were used to directly treat the carrier protein-containing multiple pass dialysis fluid.

[0321] Preferably, in all of the above kits 4A-4G a stabilizer/nutrient composition (c5) with the following components:

TABLE-US-00028 Na-caprylate (C.sub.8H.sub.15O.sub.2Na) 240 mmol/l Glucose 40 w/w %
was used in addition to the acidic composition (a) and to the alkaline composition (b).

[0322] In the above kits, calcium was provided in the acidic composition (a). The source of calcium was CaCl.sub.2. Different acidic compositions (a) were provided, which differed in the calcium concentration. Acidic compositions (a) having the following calcium concentrations were provided in a kit as described above:

[0323] 1.9 mmol/l, 2.06 mmol/l, 2.2 mmol/l, 2.32 mmol/l, 2.48 mmol/l, 2.72 mmol/l and 2.88 mmol/l, respectively.

[0324] These different calcium concentrations were tested in a kit as described above, at a pH value of the dialysis fluid of 9.

[0325] The results are shown in FIG. 10. These results show that a calcium concentration of at least 2.48 mmol/l was necessary to obtain a value of ionized calcium above 1.0 mmol/l in the blood. A calcium concentration of at least 2.88 mmol/l was necessary to obtain a calcium level of about 1.1 mmol/l in the blood.

[0326] In the next step, the effects of the highest calcium concentration (2.88 mmol/l) was evaluated at a pH of 7.45 of the dialysis fluid. Under such conditions, a calcium level of 1.7 mmol/l was observed in the blood. Since a physiological calcium level in the blood is in the range from 1.0-1.7 mmol/l, the highest calcium concentration (2.88 mmol/l) in the acidic composition (a) still resulted in a physiological calcium level in the blood.

Example 5

Removal of Copper from Blood Using a Kit According to the Present Invention

[0327] To assess the ability of the kit according to the present invention to remove copper from blood, experiments were performed using porcine blood and the dialysis device LK2001 (Hepa Wash GmbH, Munich, Germany). In this experiment, a kit comprising the following compositions was used:

[0328] The acidic composition (a) comprising a biologically compatible acid is an aqueous solution with the following components:

TABLE-US-00029 HCl 164.0 mmol/l NaCl 12.0 mmol/l KCl 7.6 mmol/l Na.sub.2HPO.sub.4 2H.sub.2O 1.0 mmol/l MgCl.sub.2 6H.sub.2O 1.0 mmol/l CaCl.sub.2 2H.sub.2O 1.9 mmol/l pH 1.05

[0329] The alkaline composition (b) comprising a biologically compatible base is an aqueous solution with the following components:

TABLE-US-00030 NaOH 160.0 mmol/l Na.sub.2CO.sub.3 54.0 mmol/l pH 12.6

[0330] More preferably, in addition to the acidic composition (a) and to the alkaline composition (b), a stabilizer/nutrient composition (c5) with the following components:

TABLE-US-00031 Na-caprylate (C.sub.8H.sub.15O.sub.2Na) 240 mmol/l Glucose 40 w/w %

[0331] The acidic composition (a) and the alkaline composition (b) of this kit were used to directly treat the carrier protein-containing multiple pass dialysis fluid.

[0332] Porcine blood was treated for 2 h in the dialysis device LK2001 (Hepa Wash GmbH, Munich, Germany) as described in Example 2 and the concentration of copper in the blood was measured.

[0333] Results are shown in FIG. 11. In about 40 minutes the concentration of copper was reduced from 124.20 mol/l to 74.40 mol/l. In other words, more than 40 percent of copper were removed during dialysis.

Example 6

Influence of Distinct Protein Stabilizers on the Stability of Albumin

[0334] To assess the influence of distinct protein stabilizers on the stability of albumin in a method as described in Example 2, a simulation model for the neutralization zone was developed. The term neutralization zone, as used herein, refers to that zone in the dialysis apparatus, where the mixing of the first flow of the carrier protein-containing multiple pass dialysis fluid treated with the acidic composition (a) with the second flow of the carrier protein-containing multiple pass dialysis fluid treated with the alkaline composition (b) occurs after their separation, as described in Example 2. In the schematic representation of the exemplified dialysis system shown FIG. 1, the neutralization zone is referred to as VIII. In the method of Example 2, the neutralization zone is the zone, in which the carrier protein, such as albumin, is particularly prone to degradation.

[0335] Preparation of the Dialysis Fluid (Dialysate)

[0336] To test the stability of albumin in this simulation model, the solutions of dialysate were freshly prepared before the beginning of every experiment. The dialysate may be prepared in a large canister (33), for example as shown in FIG. 12. To prepare the dialysate the following acidic composition (a) and the alkaline composition (b) were used:

[0337] The acidic composition (a) comprising a biologically compatible acid is an aqueous solution with the following components:

TABLE-US-00032 HCl 164.0 mmol/l NaCl 12.0 mmol/l KCl 7.6 mmol/l Na.sub.2HPO.sub.4 2H.sub.2O 1.0 mmol/l MgCl.sub.2 6H.sub.2O 1.0 mmol/l CaCl.sub.2 2H.sub.2O 1.9 mmol/l pH 1.05

[0338] The alkaline composition (b) comprising a biologically compatible base is an aqueous solution with the following components:

TABLE-US-00033 NaOH 160.0 mmol/l Na.sub.2CO.sub.3 54.0 mmol/l pH 12.6

[0339] To prepare the dialysate the acidic composition (a) and the alkaline composition (b) were mixed and (osmosis) water was added to obtain the concentrations shown in table 2.

[0340] The dialysis fluid used had a pH of 7.45 and comprised the components as shown in Table 2 below:

TABLE-US-00034 TABLE 2 Na.sup.+ 138.00 mmol/l K.sup.+ 2.50 mmol/l Ca.sup.2+ 1.50 mmol/l Mg.sup.2+ 0.50 mmol/l Cl.sup. 110.00 mmol/l HCO.sub.3.sup. 32.00 mmol/l Glucose 1.00 g/l Albumin 30.00 g/l

[0341] The concentration of electrolytes was controlled such that it was comparable with the physiological values in the human body and in order to obtain constant conditions in the fluid.

[0342] The dialysate as shown in table 2 was then filled into several smaller canisters (34), as shown in FIG. 12. To each of canisters (34), a distinct type and/or concentration of stabilizers was added, as shown in Table 3, and mixed. Therefore, each of the canisters (34) contained the same dialysate (as described in table 2), but differed in the type of stabilizer and/or concentration of the stabilizer, as shown in table 3.

[0343] Experiments 01 - 24

[0344] All experiments 01 to 24 were performed according to the detailed description of the Stabilization test below. The solutions used and test steps were the same for all experiments but differed only in the stabilizer composition (c1) comprising different stabilizers according to table 3. The stabilizer concentration shown in table 3 is the concentration of each stabilizer in the dialysate in each of the canisters (34), respectively.

[0345] In experiments 01-23 different stabilizers were tested. In experiment 24 no stabilizer was added (control experiment). All experiments differed only in the stabilizer used, as is shown in Table 3:

TABLE-US-00035 TABLE 3 Experiment Stabilizer Concentration 01 arginine 10 mmol/l 02 betaine 5 mmol/l 03 dextran 7.5 mmol/l 04 desoxycholic acid 1 mmol/l 05 caprylate 10 mmol/l 06 acetyltryptophan 10 mmol/l 07 caprylate 5 mmol/l 08 caprylate 2.5 mmol/l 09 caprylate 1.25 mmol/l 10 heptanoic acid 2.1 mmol/l 11 hexanoic acid 2 mmol/l 12 capric acid 2.2 mmol/l 13 caprylic acid 2.7 mmol/l 14 lauric acid 2.5 mmol/l 15 myristic acid 2.5 mmol/l 16 palmitic acid 0.1 mmol/l 17 stearic acid 0.1 mmol/l 18 oleic acid 0.25 mmol/l 19 linoleic acid 0.1 mmol/l 20 linolenic acid 0.1 mmol/l 21 arachidonic acid 0.1 mmol/l 22 eicosapentaenoic 0.1 mmol/l acid 23 docosahexaenic 0.1 mmol/l acid 24 0 In summary, in experiments 01-24 only the stabilizer composition (c1) differed.

[0346] Experimental Setup and Measuring Equipment

[0347] 1) The temperature and pH-values were measured with pH-meters M700C (Mettler Toledo Company, Urdorf, Switzerland), with a pH sensor type InPro 3250.

[0348] 2) The Hach Model 2100P ISO Portable Turbidimeter (HACH, Dusseldorf, Germany) was used to measure the albumin's turbidity. The general description of the Turbidimeter is explained below. [0349] Turbidity [0350] Turbidity was used for many years as a surrogate for monitoring the combined quantity of particulate material in a water sample. It has been one of the parameters used to provide a basic assessment of water quality. In the present stabilization test the turbidity measurements were used to define the denaturation of the dialysate. Turbidity can be defined as a decrease in the transparency of suspended and some dissolved substances, which causes incident light to be scattered, reflected and attenuated rather than transmitted in straight lines; the higher the intensity of the scattered or attenuated light, the higher the value of turbidity. [0351] Characteristics [0352] Turbidity can be expressed in nephelometric turbidity units (NTU). Depending on the method used, the turbidity units as NTU can be defined as the intensity of light at a specified wavelength scattered or attenuated by suspended particles or adsorbed at a method-specified angle, usually 90 degrees, from the path of the incident light compared to a synthetic chemically prepared standard. [0353] The measurement of turbidity is not directly related to a specific number of particles or to a particle shape. As a result, turbidity has historically been seen as a qualitative measurement. Currently, the NTU unit is used for all turbidity measurements and the reported value does not have any traceability to the instrument technology used. At the very last, the units should be listed to the level of NTU (white light, 90 degree detection only), FNU (Formazin Nephelomeric Unit860 nm Light with 90-degree detection) or FAU (Formazin Attenuation Unitthe detection angle is 180 degrees of the incident light beam) to the measured unit. [0354] The turbidity value is a quantitative statement of the qualitative phenomenon of turbidity. The objective of measuring turbidity is to obtain information on the concentration of scattering particles in a medium (concentration of solids). This can be done using one of two methods, which fundamentally different: determination of the light loss of the transmitted beam (scatter coefficient) or determination of the intensity of the light scattered sideways. [0355] Practical interpretation of the turbidity value is achieved by comparison with a standard suspension, i.e. turbidimeters are calibrated with a reference solution (formazine). An instrument that has been calibrated with formazine will measure any formazine concentration correctly. Regarding other turbid media, one cannot be certain of a direct correlation between turbidity value and solids concentration, because the reading will be affected also by particle size and the refractive index of the particles in relation to the medium. [0356] Attempts to compare the readings produced by different instruments are admissible only if they have the same characteristics with regard to wavelength of the light, scatter angle, optical configuration, calibration and colour compensation. For continuous measurements in those experiment processes, the measuring technique applied (photometer) is also extremely important because of the need for high stability. [0357] The ratio optical system includes a LED lamp, a 90 detector to monitor scattered light and a transmitted light detector. The microprocessor calculates the ratio of signals from the 90 and transmitted light detector. This ratio technique corrects for interferences from color and/or light absorbing materials (such as activated carbon) and compensates for fluctuations in lamp intensity, providing long-term calibration stability. The optical design also minimizes stray light, increasing measurement accuracy. [0358] 3) The Vitros 250 Chemistry System [0359] The concentration of albumin and other electrolytes were measured during those experiments using the Vitros 250 Chemistry System (Johnson and Johnson, Neckargemuend, Germany). [0360] The Vitros 250 Chemistry System is an automated clinical chemistry system used for discrete quantitative measurements of analytic concentrations in human fluid specimens. The Vitros 250 System has a throughput of up to 250 results per hour. Methodologies include colorimetric, potentiometric, immuno-rate, and rate tests using multi-layer Vitros Chemistry Slides. [0361] The slides are packaged in cartridges specific for each test type. Cartridges contain either 18 or 50 slides. The analyzer uses each slide once and after the slide is used, it is discarded. Prior to the sample processing, the cartridges were loaded, the system was calibrated and the samples were programmed. [0362] The unique properties of these slides eliminate the need to store, mix, and dispose of liquid reagent chemicals and permit reliable analyses with a very small volume of sample. [0363] A single test result takes approximately two to eight minutes, depending upon the type of test.

[0364] Stabilization Test

[0365] As already mentioned, a simulation model for the neutralization zone was established in order to evaluate the denaturation of albumin (dialysate) in a method as described in Example 2 and to compare the effect of different protein stabilizers.

[0366] FIG. 12 provides a schematical overview over the stabilization test, which comprises the following steps:

[0367] Step I): A solution comprising HSA, electrolyte and other desired chemicals as described above (e.g., Table 2) is filled into a canister (33), which is kept in 40 C. This solution represents the dialysis fluid/dialysate solution.

[0368] Step II): The dialysis fluid is then filled into smaller canisters (34). To each canister (34) a different stabilizer was added. An alkaline composition (31; for example 3 M sodium hydroxide as described below) was then added to the dialysate canister (34) to simulate the alkaline level of the dialysis machine.

[0369] Step III): After variable time, an acidic composition (32; for example 0.5 M hydrochloric acid as described below) was added to the dialysate canister (34) to simulate the acid level of the dialysis machine.

[0370] Step IV): the turbidity of samples was then measured with the HACH 2100P portable turbidimeter.

DETAILED DESCRIPTION

[0371] I) An albumin-comprising dialysis fluid was prepared from a 5% human serum albumin (HSA) by mixing the acidic composition (a) and the alkaline composition (b) and the necessary solutions and chemicals as known to the skilled person and described in the literature. The solutebuffer mixtures were prepared to a final HSA concentration of 30 mg/ml (0.0454 mmol/L) and, thereafter, filled into 1 L glass canister (33) and mixed continuously with a magnetic stir for ten minutes to dissolve all chemicals in the dialysate. The concentration of albumin was measured before the beginning of experiments using the Vitros 250 Chemistry System. Then the dialysate was separated in 10 small glasses (34), for each sample in 80 ml (same experiment to determine the denaturation time of the dialysate).

[0372] The samples were then placed in the water bath in twenty minutes. This was utilized to maintain the dialysate temperature in the range of 400.3 C. For the monitoring and controlling of dialysate pH and temperature, a pH electrode with an integrated temperature sensor was inserted into the dialysate canister.

[0373] II) When the samples reached the desired temperature of 40 C., 3M sodium hydroxide (31) was added to the dialysate to achieve the desired pH of 11.6; the amount of the added alkali was recorded.

[0374] After variable mixing time (5, 10, 15 min etc.) with akali, 0.5 M hydrochloric acid (32) was added to the dialysate to achieve pH 3; the amount of the added acid was also recorded.

[0375] IV) The concentrations of Na, Cl, Ca, Mg and total protein in the samples (34) were then determined using the Vitros 250 Chemistry System. The results of concentration were then compared to the normal physiological range. The turbidity of the samples was then measured with the HACH 2100P portable turbidimeter. From the measured turbidity, the degree of denaturation of HSA was deduced. The purpose of the stabilization test was to delay the time of denaturation after the alkali was added.

[0376] Results:

[0377] In control experiment 24, without adding additional stabilizers, albumin denatured in the dialysis fluid within 9.9 min1.3 min. Without addition of a stabilizer, the time to reach an increase of 50% in turbidity was 20.31.9 min.

[0378] Addition of arginine, betaine, dextran, sorbitol, gluconate, sulfate, or of any of the fatty acids heptanoic acid, hexanoic acid, capric acid, caprylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, arachidonic acid, eicosapentaenoic acid or docosahexaenic acid resulted in an improvement (i.e. prolongation) of the denaturation time in the range of 11.2-22.5% as compared to a dialysis fluid without addition of a stabilizer.

[0379] Desoxycholic acid pronouncedly increased the denaturation time to 272.1 min. Desoxycholic acid is a naturally occurring substance and is transferred from the blood to the albumin-containing dialysis fluid.

[0380] The addition of caplylate 10 mmol/l, 5 mmol/l, 2.5 mmol/l and 1.25 mmol/l resulted in an even more pronounced improvement (i.e. prolongation) of the denaturation time as compared to a dialysis fluid without addition of a stabilizer or with the addition of the stabilizers mentioned above. Namely, caprylate increased the denaturation time to 30.566.07 min.

Example 7

Effect of Different Protein Stabilizers on the Functionality of Albumin

[0381] In addition to the above Example assessing the influence of various stabilizers on the stability of albumin in the dialysis fluid (denaturation time), the present Example addresses the effect of different stabilizers on the functionality of albumin. To this end, the method described in Example 2 (for bilirubin removal see Example 3, FIG. 2A) and the dialysis fluid, the acidic composition (a) and the alkaline composition (b) as described in Example 6 were used. The bilirubin concentration in blood was 510 mol/l and the porcine blood was treated for one hour in the LK2001 (Hepa Wash GmbH, Munich, Germany).

[0382] In the present Example, it was tested whether any of the stabilizers would show an additional effect on bilirubin removal when added to the albumin-containing dialysis fluid. To this end, each of the stabilizers shown in table 4 was separately tested in the present experiment. The different concentrations of the stabilizers in the dialysate are shown in table 4.

[0383] Table 4 below shows the results (bilirubin elimination from the blood in %). For the control experiment all stabilizers were removed from the albumin solution and no additional stabilizers were added during the treatment.

TABLE-US-00036 TABLE 4 Bilirubin Compound Concentration elimination in % control 30 arginine 10 mmol/l 35 betaine 5 mmol/l 32 dextran 7.5 mmol/l 32 desoxycholic acid 1 mmol/l 40 caprylate 10 mmol/l 84 acetyltryptophan 10 mmol/l 79 caprylate 5 mmol/l 78 caprylate 2.5 mmol/l 71 caprylate 1.25 mmol/l 62 heptanoic acid 2.1 mmol/l 38 hexanoic acid 2 mmol/l 36 capric acid 2.2 mmol/l 37 caprylic acid 2.7 mmol/l 40 lauric acid 2.5 mmol/l 35 myristic acid 2.5 mmol/l 35 palmitic acid 0.1 mmol/l 31 stearic acid 0.1 mmol/l 31 oleic acid 0.25 mmol/l 51 linoleic acid 0.1 mmol/l 32 linolenic acid 0.1 mmol/l 33 arachidonic acid 0.1 mmol/l 31 eicosapentaenoic acid 0.1 mmol/l 33 docosahexaenic acid 0.1 mmol/l 32

[0384] Accordingly, the best results were achieved with caprylate at all concentrations tested and with acetyltryptophan. However, tryptophan and acetyltryptophan are not stable in solution. All tested fatty acids improve the detoxification of bilirubin. being better than the other classes of stabilizers the maximum effect was a 84% reduction by addition of caprylate with a concentration of 10 mmol/l.

Example 8

Influence of Different Concentrations of Caprylate on the Stability of the Carrier Protein

[0385] To assess the ability of kits according to the present invention comprising different concentrations of caprylate on the stability of the carrier protein such as albumin, the removal of bilirubin from blood was tested using kits according to the present invention comprising different concentrations of caprylate. Experiments were performed using porcine blood and the dialysis device LK2001 (Hepa Wash GmbH, Munich, Germany). In this experiment, kits comprising the following compositions were used:

[0386] The acidic composition (a) comprising a biologically compatible acid is an aqueous solution with the following components:

TABLE-US-00037 HCl 164.0 mmol/l NaCl 12.0 mmol/l KCl 7.6 mmol/l Na.sub.2HPO.sub.4 2H.sub.2O 1.0 mmol/l MgCl.sub.2 6H.sub.2O 1.0 mmol/l CaCl.sub.2 2H.sub.2O 2.8 mmol/l pH 1.05

[0387] The alkaline composition (b) comprising a biologically compatible base is an aqueous solution with the following components:

TABLE-US-00038 NaOH 160.0 mmol/l Na.sub.2CO.sub.3 54.0 mmol/l pH 12.6

[0388] The acidic composition (a) and the alkaline composition (b) of the kits were used to directly treat the carrier protein-containing multiple pass dialysis fluid.

[0389] In addition to the acidic composition (a) and to the alkaline composition (b), a stabilizer/nutrient composition (c5) with the following components:

TABLE-US-00039 Na-caprylate (C.sub.8H.sub.15O.sub.2Na) 0-240 mmol/l Glucose 40 w/w %

[0390] Identical acidic compositions (a) and alkaline compositions (b) were used in all kits. The kits differed only in the concentration of Na-caprylate (C.sub.8H.sub.15O.sub.2Na). Table 5 shows the Na-caprylate (C.sub.8H.sub.15O.sub.2Na) concentrations used.

TABLE-US-00040 TABLE 5 Kit/ Na-caprylate Referred to in experiment concentration Fig. 13 as 8A 0 (control) 0 mmol/h 8B 240 mmol/l 17 mmol/h 8C 240 mmol/l 60 mmol/h

[0391] For each kit/experiment, porcine blood was treated for 4 h in the dialysis device LK2001 (Hepa Wash GmbH, Munich, Germany) as described in Example 2 and the concentration of bilirubin in the blood was measured.

[0392] Results are shown in FIG. 13. As can be retrieved from FIG. 13, the higher the concentration of caprylate added to the dialysate, the more bilirubin is removed. These results indicate that the stability of albumin increases with higher concentrations of caprylate.

Example 9

Stability of Glucose in Solutions with or without Caprylate

[0393] To assess the influence of a protein stabilizer, such as caprylate, on the stability of a sugar, such as glucose, when present in the same composition, HMF (5-(Hydroxymethyl)-2-furaldehyd) levels were assessed. HMF is an organic compound derived from dehydration of certain sugars. Accordingly, the HMF level is indicative for the stability of sugars with the more HMF the less stable the sugar.

[0394] To this end, a stabilizer/nutrient composition (c5) comprising 428 mmol/l C.sub.8H.sub.15NaO.sub.2 and 2220 mmol/l D-glucose and a nutrient composition (c2) comprising 2220 mmol/l D-glucose, but no caprylate, were exposed to different temperatures and the HMF levels were assessed.

[0395] Results are shown in FIG. 14. As can be retrieved from FIG. 14, D-glucose in a stabilizer/nutrient composition (c5), which comprises for example caprylate, (FIG. 14B) is more stable then D-glucose alone in a nutrient composition (c2) (FIG. 14A). 5-(Hydroxymethyl)-2-furaldehyd (HMF) is a dehydration product of D-Fructose. Therefore, the higher the concentration of HMF the less stable the glucose in the composition. In general, FIG. 14 shows that higher temperatures lead to an increase in HMF concentration. The composition without stabilizer shown in FIG. 14A shows at all storage temperatures considerably more HMF as compared to the composition with stabilizer shown in FIG. 14B. Therefore, the addition of a stabilizer to the composition increases the stability of glucose.