A phosphate binding assay for sevelamer hydrochloride by ion chromatography.
Sevelamer hydrochloride is a cross-linked polymeric amine; it is the active ingredient of Renagel capsules. Renagel is indicated for the control of hyperphosphatemia in patients with end-stage renal disease. An in vitro phosphate-binding assay is required to measure the drug's efficacy. The assay developed for this purpose involves mixing the drug (polymer) with a solution of known phosphate concentration, filtering off the polymer-phosphate complex, and quantitating the unbound phosphate concentration by ion chromatography. The binding capacity, reported as mmol of phosphate bound g of polymer(-1), is calculated from the calculated amount of bound phosphate and the weight of polymer used. The method has been validated for accuracy, precision, linearity, range, and ruggedness.
Mazzeo
J R
JR
GelTex Pharmaceuticals, Waltham, MA 02154, USA. www.geltex.com.
Peters
R M
RM
Hanus
M R
MR
Chen
X
X
Norton
K A
KA
D002852:Chromatography, Ion Exchange / Q000379:methods*; D011073:Polyamines / Q000737:chemistry* / Q000378:metabolism; D011786:Quality Control; D015203:Reproducibility of Results; D000069603:Sevelamer
D011073:Polyamines; D000069603:Sevelamer