Figure 1.

Chemical structure of sevelamer hydrochloride and carbonate.

Notes: a and b, number of primary amine groups (a + b = 9); c, number of crosslinking groups (c = 1); n, fraction of protonated amines (hydrochloride) (n = 0.4); m, large number to indicate extended polymer network. The primary amine groups shown in the structure are derived directly from poly(allylamine hydrochloride). The cross-linking groups consist of 2 secondary amine groups derived from poly(allylamine hydrochloride) and 1 molecule of epichlorohydrin.21