A formulation of a sparingly water-soluble, crystalline pharmaceutically active agent wherein the active agent is converted to and stabilized in its amorphous form as a solid solution of a normally hydrophobic vehicle is described. The amorphous state is stabilized by the composition of the formulation, providing long shelf life of the improved composition. This stabilized formulation also provides increased solubility and bioavailability of the active agent. Solutions of the active agent are stabilized by the composition, preventing recrystallization and precipitation of the less soluble, crystalline form of the active agent from aqueous solutions thereof.