Abstract
Transition temperature and heat of transition between barbital forms I and II were found to be 93° and 210 cal/mole, respectively, measuring their initial dissolution rates by the method reported in the previous paper. The latter value is reasonably close to the value of 330±15 cal/mole obtained by differential scanning calorimetry (DSC). The data obtained in this study indicates that forms I and II are enantiotropic contrary to such a statement appeared in literature as they are monotropic. Furthermore, it was found that there is little difference in solubility values of barbital forms I and II.
