1-[2-(1-Hydroxycyclohexyl)-2-(4-methoxyphenyl)ethyl]dimethylammonium chloride (venlafaxine hydrochloride)

Venlafaxine Caffeic Acid Salt: Synthesis, Structural Characterization, and Hypoglycemic Effect Analysis

Depression is a recurrent and chronic mental disorder requiring long-term treatment. Major depressive disorder is present in 15-20% of patients with type 1 or type 2 diabetes. Large-scale evidence revealed that depression and depressive symptoms are independent risk factors for the development of type 2 diabetes, and they may contribute to hyperglycemia and even accelerate the premature onset of diabetes complications. Venlafaxine is a clinical first-line antidepressant used for more than 30 years. Recently, clinical reports showed that venlafaxine overdose might cause hypoglycemia. Venlafaxine is insoluble and salt formation technology is the most appropriate method to improve the physicochemical properties and the pharmacokinetic profile of the drug. In the present work, the use of the solvent evaporation method, slurry, and the liquid-assisted grinding method resulted in the crystalline salt venlafaxine-caffeic acid (1:1). The compounds were characterized using a series of solid-state techniques, viz., powder X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, Fourier transform infrared spectroscopy, and solid-state nuclear magnetic resonance, and the crystal structure was determined by single-crystal X-ray diffraction. Besides, a comparative study of solubility, dissolution, and hypoglycemic activity of the parent drug and the new salt has been carried out. The tested venlafaxine-caffeic acid salt showed about 16-fold higher solubility than the pure drug. Moreover, the glucose consumption assay results showed that the novel salt possesses potent hypoglycemic activity in vitro, suggesting that it is a promising candidate effective for major depressive disorder patients with type 2 diabetes.

Salt or/and cocrystal? The case of the antidepressant drug venlafaxine

The VLF–DA (1 : 2) salt cocrystal exhibited distinctively different properties in terms of kinetic stability, solubility, and bioavailability from the VLF–DA (1 : 1) salt.

Invariom based electron density studies on the C/Si analogues haloperidol/sila-haloperidol and venlafaxine/sila-venlafaxine

Hirshfeld surfaces of haloperidol hydropicrate (left) and sila-haloperidol hydrochloride (right) show comparable sites of ED concentrations due to comparable intermolecular environments.

Venlafaxine besylate monohydrate

The title compound {systematic name: [2-(1-hydroxycyclohexyl)-2-(4-methoxyphenyl)ethyl]dimethylazanium benzene-sulfonate monohydrate}, C17H28NO2 (+)·C6H5O3S(-)·H2O, is a besylate salt hydrate of the anti-depressant drug venlafaxine. In the crystal, besylate anions and water mol-ecules self-assemble, forming hydrogen-bonded dimers linked around inversion centers, with graph set R 4 (4)(6). The crystal packing features a chain of alternate dimers and venlafaxine cations in the b-axis direction with the components linked by O-H⋯O hydrogen bonds and C-H⋯O and C-H⋯π inter-actions. This is the first example of a venlafaxine cation with a closed conformation, as it features an intra-molecular N-H⋯O inter-action involving the protonated N atom.

Desvenlafaxinium chloranilate ethyl acetate solvate

In the cation of the title compound, C₁₆H₂₆NO₂⁺·C₆HCl₂O₄⁻·C₄H₈O₂, the 1-hy­droxy-cyclo­hexyl ring adopts a slightly distorted chair conformation. The dihedral angle between the mean planes of the 1-hy­droxy­cyclo­hexyl and 4-hy­droxy­phenyl rings is 84.0 (8)°. In the anion, the hydroxyl H atom is twisted slightly out of the ring plane with a C—C—O—H torsion angle of −171.9°. Disorder was modeled for the methyl group of the acetate group in the solvate with an occupancy ratio of 0.583 (15): 0.417 (15). In the crystal, O—H⋯O hydrogen bonds are observed between cations and between cations and anions, while bifuricated N—H⋯(O,O) cation–anion hydrogen bonds are also present, forming chains along [010] and [100]. In addition weak cation–anion and cation–solvate C—H⋯O inter­actions occur.

2-(Cyclohexa-1,4-dienyl)-2-(4-methoxyphenyl)-N,N-dimethylethanaminium chloride

In the title compound, C₁₇H₂₄NO⁺·Cl⁻, the cyclo­hexa-1,4-diene ring, which is almost planar, with a maximum deviation of 0.024 (4) Å from the mean plane, makes a dihedral angle of 66.4 (1)° with the benzene ring. In the crystal, inter­molecular N—H⋯Cl and C—H⋯Cl hydrogen bonds link the mol­ecules into an infinite chain along the b axis.

Structural basis for bending of organic crystals

Bending is observed in organic crystals when the packing is anisotropic in such a way that strong and weak interaction patterns occur in nearly perpendicular directions.