Thermochemical analysis of the dissolution process of Griseofulvin.

Very often poor water solubility limits the therapeutic use of drug molecules. In order to develop strategies to overcome this handicap a basic understanding of this phenomenon is needed. In this paper Griseofulvin is used as a model substance. According to the Hess theorem the direct dissolution of Griseofulvin is replaced by a series of alternative processes which in their combination have the same starting point as well as the same endpoint as the direct dissolution. The energies associated with these alternative processes however can be determined more exactly than the dissolution energy. In cases where the measurement of an energy is impossible, e.g. the transfer energy of single molecules from the vapor phase into water, this energy is calculated by quantum chemical methods. In addition these alternative processes allow for a better understanding of the elementary steps involved in the dissolution process. The energies determined for the various alternative processes are compared with the dissolution energies as calculated by means of AMSOL. An excellent agreement can be observed.