Unprecedented sodium–oxygen clusters in the solid-state structure of trisodium hydrogentetravalproate monohydrate: A model for the physiological activity of the anticonvulsant drug Epilim®

The first crystal structure determination of one of the solid forms of sodium valproate revealed that the crystal is a 3:1 solvate of sodium valproate and valproic acid. The anion symmetry-directed formation of stable sodium–oxygen clusters protected by alkyl layer which can act as lipophilic micelles may be important for understanding the strong anticonvulsant activity of the valproate ion.

Graphical abstractThe first structure determination of one form of sodium valproate, which is the basis of the anticonvulsant drug Epilim® for treatment of epilepsy and bipolar disorders, revealed that the compound is, in fact, a 3:1 co-crystal of sodium valproate and valproic acid. The anion symmetry-directed formation of stable sodium–oxygen clusters protected by a lipophilic alkyl layer may be the key for the strong physiological activity of this important compound.Figure optionsDownload full-size imageDownload as PowerPoint slide