SOLID-STATE INVESTIGATION OF MEFLOQUINE HYDROCHLORIDE

Mefloquine hydrochloride was crystallized under different conditions and the products were studied by thermal analysis, IR spectroscopy and X-rav diffraction. It was demonstrated that different conditions of crystallization resulted in different crystal structures. The alpha- and delta-modifications were hydrates, the beta- and gamma-forms were polymorphs, the epsilon-form was an acetone solvate and theta-mefloquine was tetrahydrofuran solvate. During long storage at room temperature, the alpha-, delta- and theta-forms of mefloquine hydrochloride were transformed. By heat treatment of the delta-, epsilon and theta-modifications, a new crystal structure was obtained.