Synthesis, crystal structure and Hirshfeld surface analysis of sulfamethoxazolium methyl-sulfate monohydrate.

The mol-ecular salt sulfamethoxazolium {or 4-[(5-methyl-1,2-oxazol-3-yl)sulf-amo-yl]anilinium methyl sulfate monohydrate}, CHNOS·CHOS·HO, was prepared by the reaction of sulfamethoxazole and HSO in methanol and crystallized from methanol-ether-water. Protonation takes place at the nitro-gen atom of the primary amino group. In the crystal, N-H⋯O hydrogen bonds (water and methyl-sulfate anion) and inter-molecular N-H⋯N inter-actions involving the sulfonamide and isoxazole nitro-gen atoms, link the components into a tri-dimensional network, additional cohesion being provided by face-to-face π-π inter-actions between the phenyl rings of adjacent mol-ecules.

Preparation and characterization of new salts of tioconazole. Comparison of their dissolution performance.

Tioconazole is an effective antifungal agent with very low solubility in aqueous media, which limits its bioavailability and efficacy. Aiming to overcome the drug limitations by improving the solubility of this active pharmaceutical ingredient, solution precipitation techniques were employed to prepare four new crystalline salts, namely the mesylate, tosylate, maleate (1:1), and fumarate (1:1) hemihydrate. The thermal stabilities, dissolution properties, and structural characteristics of the solids were determined, and the study was extended to compare their properties with the already-known oxalate salt.

Characterization of the hydrochloride salt hemihydrate as a new salt of the antifungal agent tioconazole.

Tioconazole is an effective antifungal agent, which has a very low solubility in aqueous media, that limits its bioavailability and efficacy. In an effort to overcome the drug limitations by improving its solubility, the hydrochloride salt was prepared in methanolic 1 M HCl and obtained as the hemihydrate, as demonstrated by elemental analysis. Single crystals were grown by slow evaporation from an aqueous 1 M HCl solution and their structure was determined using single-crystal X-ray diffraction at 302 K.

Selected Aspects of the Analytical and Pharmaceutical Profiles of Nifurtimox.

Nifurtimox is a nitroheterocyclic drug employed for treatment of trypanosomiases (Chagas disease and West African sleeping sickness); its use for certain cancers has also been assessed. Despite having been in the market for over 50 years, knowledge of nifurtimox is still fragmentary and incomplete. Relevant aspects of the chemistry and biology of nifurtimox are reviewed to summarize the current knowledge of this drug.

Solid-state properties of Nifurtimox. Preparation, analytical characterization, and stability of an amorphous phase.

Nifurtimox (NFX) is a nitrofuran derivative used to treat Chagas disease, a neglected disease caused by the protozoan Trypanosoma cruzi. The drug is very sparingly soluble in aqueous media and no other solid phases of NFX have been reported to date. The preparation of the amorphous mode of NFX is reported, as well as its characterization by hot stage microscopy, thermal (differential scanning calorimetry and thermogravimetric analysis), spectroscopic (solid state nuclear magnetic resonance, mid-infrared, and near-infrared), diffractometric and functional (powder dissolution rate) means.

Form quantitation in desmotropic mixtures of albendazole bulk drug by chemometrics-assisted analysis of vibrational spectra.

Albendazole is a benzimidazole-type active pharmaceutical ingredient, and one of the most effective broad-spectrum anthelminthic agents. The drug has two solid-state forms (ALB I and ALB II) which are desmotropes; both of them seem to be currently marketed. However, using the wrong crystalline solid form for formulation may have an undesired impact on the physicochemical and/or bioavailability properties of the drug product.