title: The effect of pH on polymorph formation of the pharmaceutically active compound tianeptine.
abstract: The anti-depressant pharmaceutical tianeptine has been investigated to determine the dynamics of polymorph formation under various pH conditions. By varying the pH two crystalline polymorphs were isolated. The molecular and crystal structures have been determined to identify the two polymorphs. One polymorph is an amino carboxylic acid and the other polymorph is a zwitterion. In the solid state the tianeptine moieties are bonded through hydrogen bonds. The zwitterion was found to be less stable and transformed to the acid form. During this investigation an amorphous form was identified.
authors.affiliation: University of Latvia, Faculty of Chemistry, Kr. Valdemara 48, Riga LV-1013, Latvia.
authors.forename: Liana
authors.initials: L
authors.lastname: Orola
authors.forename: Mikelis V
authors.initials: MV
authors.lastname: Veidis
authors.forename: Inese
authors.initials: I
authors.lastname: Sarcevica
authors.forename: Andris
authors.initials: A
authors.lastname: Actins
authors.forename: Sergey
authors.initials: S
authors.lastname: Belyakov
authors.forename: Aleksandrs
authors.initials: A
authors.lastname: Platonenko
mesh_terms: D000929:Antidepressive Agents, Tricyclic / Q000737:chemistry*; D003460:Crystallization; D006863:Hydrogen-Ion Concentration; D033362:Powder Diffraction; D017550:Spectroscopy, Fourier Transform Infrared; D013841:Thiazepines / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D000929:Antidepressive Agents, Tricyclic; D013841:Thiazepines; C050504:tianeptine