Metal ion and vitamin adsorption profiles of phosphate binder ion-exchange resins.

Abstract

AIMS:

To determine the metal ion and vitamin in vitro adsorption profile of sevelamer hydrochloride (sevelamer-HCl) and colestilan(INN)/colestimide(JAN), a novel ion-exchange resin being developed as a phosphate binder for end-stage renal disease (ESRD) patients undergoing hemodialysis, adsorption of metal ions (iron, cobalt, copper and zinc) and vitamins (B6, B12, C, K and folic acid) essential for hematopoiesis/blood coagulation was assessed.

METHODS:

Mixtures of each resin (colestilan or sevelamer-HCl, 4 mg/ml) and metal ions (Fe(III), Fe(II), Co(II), Cu(II), and Zn(II), 1 microg/ml) were adjusted to pH 1.2 or 6.8 and incubated at 37 degrees C for 1 hour. Metal ions in the recovered filtrate were detected by inductively coupled plasma optical emission spectrometry. In addition, the mixtures of each resin (4 mg/ml) and vitamins (B6, B12, C, K and folic acid, 0.5 - 250 microg/ml) were adjusted to pH 6.8 and incubated at 37 degrees C for 0.5 hour. The vitamin concentrations in the recovered filtrate were quantified by HPLC.

RESULTS:

Colestilan did not adsorb any metals tested at either pH level, whereas sevelamer-HCl adsorbed copper(II) and zinc(II) ion at pH 6.8 with adsorption ratios of 99% and 38%, respectively. Both resins showed almost complete adsorption of vitamin C, vitamin K, and folic acid, but weak adsorption of vitamin B6, and no adsorption of vitamin B12.

CONCLUSIONS:

The differing adsorption profiles for metal ions and vitamins between sevelamer-HCl and colestilan may be of importance for the individualized management of anemia and malnutrition in chronic hemodialysis patients receiving phosphate binding ion-exchange resins for the control of hyperphosphatemia.

• Authors: K Takagi, K Masuda, M Yamazaki, C Kiyohara, S Itoh, M Wasaki, H Inoue
• Journal: Clinical nephrology (Clin Nephrol) Vol. 73 Issue 1 Pg. 30-5 (Jan 2010) ISSN: 0301-0430 [Print] Germany
• PMID: 20040349 (Publication Type: Journal Article)

Chemical References

• Bile Acids and Salts
• Cations
• Ion Exchange Resins
• Metals, Heavy
• Polyamines
• Vitamins
• Sevelamer
• cholebine

Topics

• Adsorption
• Bile Acids and Salts (chemistry)
• Cations (chemistry)
• Ion Exchange Resins (chemistry)
• Metals, Heavy (chemistry)
• Polyamines (chemistry)
• Sevelamer
• Vitamins (chemistry)