Structural and theoretical studies of amantadinium fenamates.

Two new crystals of amantadinium salts were obtained from fenamic and tolfenamic acid. The salt of fenamic acid is a model compound for interaction analysis, while amantadinium tolfenamate is a composition of a drug used in the treatment of symptoms of Parkinsonism and as a nonsteroidal anti-inflammatory drug. The crystal structures were studied and a theoretical analysis of the hydrogen bonds and weak interactions was carried out using quantum theory of atoms in molecules (QTAIM) and non-covalent interaction (NCI) methods.