Evaluation of the In Vitro Efficacy of Sevelamer Hydrochloride and Sevelamer Carbonate  Yongsheng Yang, Adil Mohammad, Robert T. Berendt, Alan Carlin, Mansoor A. Khan, Patrick J. Faustino  Journal of Pharmaceutical Sciences  Volume 105, Issue 2, Pages 864-875 (February 2016) DOI: 10.1002/jps.24572 Copyright © 2016 Terms and Conditions

Figure 1 Chemical structure of sevelamer hydrochloride. a and b = number of primary amine groups, where a + b = 9; c = number of crosslinking groups, where c = 1; n = fraction of protonated amines, where n = 0.4; m = large number to indicate an extended polymer network. Journal of Pharmaceutical Sciences 2016 105, 864-875DOI: (10.1002/jps.24572) Copyright © 2016 Terms and Conditions

Figure 2 Chemical structure of sevelamer carbonate. a and b = number of primary amine groups, where a + b = 9; c = number of crosslinking group, where c = 1; m = large number to indicate extended polymer network. Journal of Pharmaceutical Sciences 2016 105, 864-875DOI: (10.1002/jps.24572) Copyright © 2016 Terms and Conditions

Figure 3 The pH-dependent phosphate binding profiles for drug products of sevelamer hydrochloride and sevelamer carbonate under pH 4.0 and pH 7.0 with 1 mM (a), 15 mM (b), and 40 mM (c) of phosphate. Journal of Pharmaceutical Sciences 2016 105, 864-875DOI: (10.1002/jps.24572) Copyright © 2016 Terms and Conditions

Figure 4 The pH-dependent phosphate binding profiles for active pharmaceutical ingredient of sevelamer hydrochloride and sevelamer carbonate under pH 4.0 and pH 7.0 with 1 mM (a), 15 mM (b), and 40 mM (c) of phosphate. Journal of Pharmaceutical Sciences 2016 105, 864-875DOI: (10.1002/jps.24572) Copyright © 2016 Terms and Conditions

Figure 5 The effect of phosphate concentration on the phosphate binding to drug products of sevelamer hydrochloride (a) and drug product sevelamer carbonate (b) under pH 4.0 with 1, 15, and 40 mM of phosphate. Journal of Pharmaceutical Sciences 2016 105, 864-875DOI: (10.1002/jps.24572) Copyright © 2016 Terms and Conditions

Figure 6 The effect of phosphate concentration on the phosphate binding to active pharmaceutical ingredient of sevelamer hydrochloride (a) and active pharmaceutical ingredient of sevelamer carbonate (b) under pH 4.0 with 1, 15, and 40 mM of phosphate. Journal of Pharmaceutical Sciences 2016 105, 864-875DOI: (10.1002/jps.24572) Copyright © 2016 Terms and Conditions

Figure 7 Comparison of phosphate binding profiles between two forms of sevelamer under pH 4.0 (a) and pH 7.0 (b) with 1 mM of phosphate. DP-HCl, sevelamer hydrochloride drug product; DP-CO, sevelamer carbonate drug product; API-HCl, sevelamer hydrochloride active pharmaceutical ingredient; API-CO, sevelamer carbonate active pharmaceutical ingredient. Journal of Pharmaceutical Sciences 2016 105, 864-875DOI: (10.1002/jps.24572) Copyright © 2016 Terms and Conditions

Figure 8 Comparison of phosphate binding profiles between two forms of sevelamer under pH 4.0 (a) and pH 7.0 (b) with 15 mM of phosphate. DP-HCl, sevelamer hydrochloride drug product; DP-CO, sevelamer carbonate drug product; API-HCl, sevelamer hydrochloride active pharmaceutical ingredient; API-CO, sevelamer carbonate active pharmaceutical ingredient. Journal of Pharmaceutical Sciences 2016 105, 864-875DOI: (10.1002/jps.24572) Copyright © 2016 Terms and Conditions

Figure 9 Comparison of phosphate binding profiles between two forms of sevelamer under pH 4.0 (a) and pH 7.0 (b) with 40 mM of phosphate. DP-HCl, sevelamer hydrochloride drug product; DP-CO, sevelamer carbonate drug product; API-HCl, sevelamer hydrochloride active pharmaceutical ingredient; API-CO, sevelamer carbonate active pharmaceutical ingredient. Journal of Pharmaceutical Sciences 2016 105, 864-875DOI: (10.1002/jps.24572) Copyright © 2016 Terms and Conditions