Crystal structure of 7-phenyl-7-(2,4,5-trimethyl-3,6-dioxo­cyclo­hexa-1,4-dien-1-yl)hepta­noate 1,3-dihy­droxy-2-(hy­droxy­meth­yl)propan-2-aminium monohydrate: a new solid form of seratrodast

In the title hydrated salt, C(4)H(12)NO(3) (+)·C(22)H(25)O(4) (−)·H(2)O, seratrodast [systematic name: 7-phenyl-7-(2,4,5-trimethyl-3,6-dioxo­cyclo­hexa-1,4-dien-1-yl)hepta­noic acid] crystallized with trometamol [systematic name: 2-amino-2-(hydroxyméth­yl)propane-1,3-diol] to form a monohydrated salt form of seratrodast. The carb­oxy­lic acid group of seratrodast has transferred its proton to the amino N atom of trometamol. In the crystal, the trometamol cations are linked to the water mol­ecules and to each other by N—H⋯O and O—H⋯O hydrogen bonds forming sheets parallel to (100). The seratrodast anions are linked to both sides of these sheets by O—H⋯O and C—H⋯O hydrogen bonds, forming a three-layer two-dimensional structure. After forming the title salt, the solubility of seratrodast was found to be greatly improved.