Fig. 11. Crystal structure of sodium zirconium cyclosilicate, (2Na·H2O·3H4SiO4·H4ZrO6)n (ZS-9). The oral drug Lokelma, used to lower K+ levels in the body. It is a cation exchanger and contains pores which bind cations, especially K+. The pores resemble those in the physiological K+ channel. Blue, O; red, Zr; green, Si (except where labelled in bottom row). Reproduced from ref. 55 with permission from Public Library of Science, copyright 2014.55.
