Abstract: A moisture stable solid valproic acid formulation is provided. The formulation comprises:55 to 65 weight percent valproic acid,10 to 25 weight percent fillers,10 to 20 weight percent disintegrants,3 to 6 weight percent binders, and0.5 to 1.2 weight percent lubricantsA preferred formulation is:60 weight percent of valproic acid,20 weight percent of magnesium oxide,15 weight percent corn or potato starch,3 weight percent polyvinylpyrrolidone,1 weight percent sodium carboxymethylcellulose,0.8 weight percent magnesium stearate.The formulations are manufactured by mxing an alcohol solution of valproic acid with the fillers, drying and then milling the mixture, adding the disintegrants and wet granulating with at least a portion of the binder. The wet granulate is dried, sized and to it is added the lubricant and any remaining binder.The lubricated granulate can be compressed into tablets without a protective coating.