Abstract
The dissolution behaviour of phenylbutazone (PBZ) polymorphs, pure α, β, and δ forms prepared by the method described in our previous paper, was investigated kinetically by the rotating disk method. The dissolution activation energies obtained by the measurement of the initial dissolution rate at various temperatures were different among three polymorphs, and those of α, β, and δ forms were 7.90, 8.93, and 4.52 kcal/mol, respectively. This result indicated the participation of interfacial chemical reaction in the dissolution of PBZ. Furthermore, it is suggested that both interfacial chemical reaction and transport process were concerned in the dissolution of PBZ as judged by the values of the dissolution activation energy.
