New Saccharin Salt of Chlordiazepoxide: Structural and Physicochemical Examination

Since the formation of organic salts can improve the solubility, bioavailability, and stability of active pharmaceutical ingredients, the aim of this work was to prepare an organic salt of chlordiazepoxide with saccharin. To achieve this goal, the saccharin salt of chlordiazepoxide was obtained from a physical mixture of both components by grinding them with a small volume of solvent and by crystallizing them with complete evaporation of the solvent. The resulting salt was examined by methods such as Powder X-ray Diffraction (PXRD), Single Crystal X-ray Diffraction (SCXRD), Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), Fourier Transform Infrared (FT-IR), and Raman spectroscopy. The results of the studies proved that saccharin salt of chlordiazepoxide crystallizes in the orthorhombic Pbca space group with one chlordiazepoxide cation and one saccharin anion in the asymmetric unit. In the crystal of the title compound, the chlordiazepoxide cation and the saccharin anion interact through strong N–H···O hydrogen bonds and weak C–H···O hydrogen bonds. The disappearance of the N–H band in the FT-IR spectrum of saccharin may indicate a shift of this proton towards chlordiazepoxide, while the disappearance of the aromatic bond band in the chlordiazepoxide ring in the Raman spectrum may suggest the formation of intermolecular hydrogen bonds between chlordiazepoxide molecules. The melting point of the salts differs from that of the starting compounds. Thermal decomposition of the salt begins above 200 °C and shows at least two overlapping stages of mass loss. In summary, the results of the research showed that the crystalline salt of the saccharin and chlordiazepoxide can be obtained by various methods: grinding with the addition of acetonitrile and crystallization from acetonitrile or a mixture of methanol with methylene chloride.

Pharmaceutical salt and salt hydrates of vortioxetine with sulfonic acid to ameliorate the solubility and hygroscopicity via the charge-assisted hydrogen bond assembly

Salt forms of vortioxetine (VOT) with three sulfonic acids have been designed and prepared in 1 : 1 stoichiometry ratio, and their crystal structures and physicochemical properties have also been characterized in detail.

No regioselectivity for the steroid α-face in cocrystallization of exemestane with aromatic cocrystal formers based on phenanthrene and pyrene

The anti-cancer steroidal drug exemestane presents significantly different behavior in cocrystallization with arenes compared with the previously explored steroid progesterone. Mechanochemical and solution-based cocrystallization of exemestane with hydroxy derivatives of phenanthrene and pyrene leads to the formation of cocrystals exhibiting clear O–H···O type arene-steroid hydrogen bonds. So far, exemestane and 1-hydroxypyrene have been observed to form only one type of cocrystal, with the 1:1 stoichiometric ratio of the two components. However, there are two stoichiometric variations of the cocrystal of 9-hydroxyphenanthrene and exemestane, with the arene:steroid stoichiometric ratio of either 1:1 or 1:2. Importantly, although cocrystallization of progesterone with the same arene cocrystal formers was previously reported to take place regioselectively through α···π contacts between the α-face of the steroid and the π-electron surface of the arene, the herein explored cocrystals of exemestane reveal α···π and β···π contacts, as well as sidewise interactions involving the arene π-system and different edges of the steroid molecule. The loss of regioselectivity for the steroid α-face in cocrystallization with the two monohydroxylated arenes is tentatively explained by the highly positive electrostatic surface potential of the steroid β-face and a diminished number of C–H groups on the α-face of exemestane compared with progesterone.

Stanozolol–aromatic carboxylic acid crystalline complexes: flexible tautomeric/ionization states and supramolecular synthons

The various supramolecular synthons are constantly spinning in the crystal world.