Glycine, N-​[2-​[2-​[2-​[bis(carboxymethyl)​amino]​-​5-​(2,​7-​dichloro-​6-​hydroxy-​3-​oxo-​3H-​xanthen-​9-​yl)​phenoxy]​ethoxy]​-​3,​4-​difluorophenyl]​-​N-​(carboxymethyl)​-​, pentapotassium salt (9CI)