Structural Studies of Two Solid Steroid Compounds

The study focused on the polymorphism and solvate forms of two steroids, androsterone and finasteride, using solid-state NMR and X-ray diffraction techniques. For androsterone, the hemihydrate and anhydrous forms were characterized, and their transformation at room temperature was observed. In the case of finasteride, the research identified inaccuracies in the patent literature, revealing that a supposed polymorph was actually a dioxane solvate hydrate. Newly prepared finasteride solvates were found to be isomorphous with each other and with a previously reported solvate, characterized as bis (finasteride) monosolvate monohydrates. The study also suggested that proton spin-lattice relaxation in these solvates is influenced by methyl group reorientation rather than solvent dynamics. Additionally, a new form X was identified, though its origin was unknown.