Drug-drug salt forms of vortioxetine with mefenamic acid and tolfenamic acid

Abstract

Two drug-drug salt forms of multimodal antidepressant drug vortioxetine (VOT), with non-sterodial anti-inflammatory drugs (NSAIDs), mefenamic acid (MFA) and tolfenamic acid (TFA), were successfully synthesized and characterized by powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC) and Fourier transform infrared (IR) analysis techniques. The single-crystal structure analysis of these two salts showed that they both formed a R44(12) tetramer architecture. The stability experiments indicated that these two salts were stable over a wide range of humidity conditions over a month. The solubility and dissolution rates of the two salts were also studied. Moreover, the solubility and IDR values of the VOT-TFA salt were higher than that of TFA in water.