3,6-Bis[2-(phosphonooxy)ethyl]-3,6-diazaoctane-1,8-diol 1,8-bis(dihydrogen phosphate)/sodium,(1:x) salt

10,10-dihydroxy-3,6-bis[2-(phosphonooxy)ethyl]-9-oxa-3,6-diaza-10-phosphadecyl dihydrogen phosphate 10-oxide, sodium salt