HCl-binding compositions for and methods of treating acid-base disorders
Pharmaceutical compositions for and methods of treating an animal, including a human, and methods of preparing such compositions. The pharmaceutical compositions contain nonabsorbable compositions and may be used, for example, to treat diseases or other metabolic conditions in which removal of protons, the conjugate base of a strong acid and/or a strong acid from the gastrointestinal tract would provide physiological benefits such as normalizing serum bicarbonate concentrations and the blood pH in an animal, including a human.
1. A method of increasing serum bicarbonate levels in an individual afflicted with chronic kidney disease (CKD) and metabolic acidosis, the method comprising oral administration of a pharmaceutical composition to increase the individual's serum bicarbonate levels wherein:
(i) the pharmaceutical composition binds HCl in the individual's digestive system when given orally,
(ii) the pharmaceutical composition increases the baseline serum bicarbonate level by at least 3 mEq/l in a placebo controlled study, said increase being the difference between the cohort average serum bicarbonate level in a first cohort at the end of the study, relative to the cohort average serum bicarbonate level in a second cohort at the end of the study, wherein the first cohort's subjects receive the pharmaceutical composition and the second cohort's subjects receive a placebo, wherein the first and second cohorts each comprise at least 25 subjects, each cohort is prescribed the same diet during the study and the study lasts at least two weeks, and
(iii) the pharmaceutical composition comprises a crosslinked amine polymer that is a copolymer comprising the residues of (a) 2-Propen-1-ylamine or a salt thereof and (b) 1,3-Bis(allylamino)propane or a salt thereof.
2. The method of claim 1 wherein the metabolic acidosis is characterized by a baseline serum bicarbonate value of less than 18 mEq/l.
3. The method of claim 1 wherein the oral administration is as frequent as at least weekly, is as frequent as at least semi-weekly, or is as frequent as at least daily within the treatment period.
4. The method claim 1 wherein the baseline serum bicarbonate value is increased to a value of at least 22 mEq/l.
5. The method of claim 1 wherein the increase in baseline serum bicarbonate value is achieved within a treatment period of less than one month, 25 days, or 3 weeks.
6. The method of claim 1 wherein the individual's serum bicarbonate value returns to the baseline value±2 mEq/I within 1 month, 3 weeks or 2 weeks of the cessation of treatment.
7. The method of claim 1 wherein the baseline serum bicarbonate value is the mean value of at least two serum bicarbonate concentrations for serum samples drawn on different days.
8. The method of claim 3 wherein the daily dose has the capacity to remove at least 7.5 mEq of HCl as it transits the digestive system.
9. The method of claim 3 wherein the daily dose is less than 100 g/day, 30 g/day or 10 g/day.
10. The method of claim 1 wherein the individual is treated for at least several months.
11. The method of claim 1 wherein the crosslinked amine polymer has a theoretical binding capacity for HCl in the range of 2 to 25 mEq/g.
12. The method of claim 1 wherein the crosslinked amine polymer is characterized by a chloride ion binding capacity of at least 1 mEq/g, 1.5 mEq/g, 2 mEq/g, 2.5 mEq/g, 3 mEq/g, 3.5 mEq/g, 4 mEq/g, 4.5 mEq/g, 5 mEq/g, 5.5 mEq/g, or 6 mEq/g, in a SIB assay.
13. The method of claim 1 wherein the crosslinked amine polymer is characterized by a ratio of an amount of bound chloride to bound phosphate in a SIB assay that is at least 0.3:1, 0.5:1, or at least 1:1, respectively.
14. The method of claim 1 wherein the crosslinked amine polymer is prepared in two steps, (i) the first step comprising a concurrent polymerization and crosslinking reaction between 2-Propen-1-ylamine or a salt thereof and (b) 1,3-Bis(allylamino)propane or a salt thereof to produce a preformed crosslinked amine polymer in which the crosslinks are primarily carbon-carbon crosslinks, and (ii) a second step in which the preformed amine polymer is further crosslinked in a substitution reaction in which a carbon-nitrogen bond is formed.
15. The method of claim 1 wherein the pharmaceutical composition comprises a crosslinked amine polymer prepared in two steps, (i) the first step comprising a concurrent polymerization and crosslinking reaction between 2-Propen-1-ylamine or a salt thereof and (b) 1,3-Bis(allylamino)propane or a salt thereof to produce a preformed amine polymer, and (ii) a second step in which the preformed amine polymer is further crosslinked in a substitution reaction with dichloroethane.