According to Hess's theorem, the thermodynamics of processes can be described by different routes that have the same start and end points as the original process. Often the energy changes associated with alternative processes can be measured with less uncertainty than the direct process. This is the case for poorly water-soluble drugs where it is hypothesized that the formation of solid Solutions Might improve drug Solubility in water. In a solid Solution, the sparingly water-soluble compound is amorphously dispersed in a highly water-soluble polymeric carrier, for example, poly(ethane-1,2-diol) (PEG) 6000 or 8000. To test this hypothesis, I model drug, (2S,6'R)-7-chloro-2',4,6-trimethoxy-6'-methyl-3H,4'H-spiro[1-benzofuran-2,1'-cyclohex[2]ene]-3,4'-dione (griseofulvin), was used that has a low water solubility. The thermodynamic properties of solid dispersions of griseofulvin in PEG 6000 were Studied. From the powder X-ray diffraction patterns, we call Conclude that solid dispersions of PEG 6000 exist in the form of a 7(2) helix. By means of high-precision calorimetry, the phase diagram of solid dispersions of griseofulvin + PEG 6000 was generated and a PEG + griseofulvin monotectic observed. Unfortunately, no information could be obtained for systems containing a mass fraction less than 0.05 griseofulvin. A quantitative determination of the crystallinity of griseofulvin showed that it exists in its solid dispersions in a completely crystallized form. In addition, we were able to show that an improvement of the water Solubility of griseofulvin was achieved by aqueous Solutions of PEG Without preparation of a melt.