Disclosed herein are oxalate salts of (RS)-7-(3-chloro-6- methyl-6,11-dihydrodibenzo[c,f] [1,2]thiazepin-11-ylamino)heptanoic acid S,S-dioxide (tianeptine oxalate) characterized by specific XRPD patterns for use in the treatment of neurocognitive dysfunction and related psychiatric disorders. These disorders include trauma- and stressor-related disorders, such as PTSD and acute stress disorder; depressive disorders including major depressive disorder, persistent depressive disorder, bipolar depression, and premenstrual dysphoric disorder; neurodegenerative diseases such as Alzheimer’s disease and multi-infarct dementia; neurodevelopmental disorders including attention-deficit/hyperactivity disorder; asthma and chronic obstructive pulmonary disorder.
Tianeptine oxalate salts and polymorphs