Comparison of Binding Parameter Constants between Sevelamer Carbonate Tablets and Renvela Tablets by a Validated Ion Chromatography Method

Abstract

Sevelamer Carbonate is a crossolinked polymeric amine, it is the active ingredient in Renvela Tablets. Sevelamer Car bonate is indicated for the control of hyperphosphatamiea in patients with end-stage renal disease. The binding parame ter constants of Sevelamer Carbonate were determined using the Langmuir approximation for the dosage form at pH 4.0 and 7.0 by Ion Chromatography. An Ion Chromatogrpahy method has been developed to estimate free phosphate in in-vitro phosphate binding study of Sevelamer Carbonate Tablets. The method is selective and capable of detecting phosphate in the presence of placebo matrix. The method has been validated with a lower limit of quantitation of 0.2 mM for Phosphate. A linear response function was established in the range of concentrations 0.2 - 30.0 mM (r > 0.99) for Phosphate. The intra and inter day precision values for Phosphate met the acceptance as per Food and Drug Admini strations guidelines. Phosphate was stable in the set of stability studies viz. bench-top and autosampler. The developed method was applied to in-vitro phosphate binding studies of Sevelamer Carbonate Tablets.