Antifungal Activity and Stability of Fluconazole Emulsion Containing Ionic Liquids Explained by Intermolecular Interactions.

This research reports accelerated stability experiments, the evaluation of intermolecular interactions, and antifungal assays for fluconazole emulsions prepared using ultrasound (US) and magnetic stirring (MS) in the presence of ionic liquids derived from 1,n-(3-methylimidazolium-1-yl)alkane bromide ([CnMIM]Br; n = 12 or 16). The goals of the investigation are to quantify the stability, identify the forces that drive the formation and stability, and determine the antifungal activity of fluconazole-containing emulsions, and corroborate the data from our previous results that indicated that the emulsion based on [C16MIM]Br seemed to be more stable. In this study, accelerated stability experiments evidenced a considerable stability for the [C16MIM]Br emulsions at two temperatures (25 and 37 °C)—the instability index increased in the following order: US40% < US20% < MS.

Supramolecular Similarity in Polymorphs: Use of Similarity Indices (I).

A systematic investigation to assess the degree of similarity between polymorphs was carried out. A similarity indices (I) approach was applied in ten series of polymorphs with different characteristics and number of molecules in the asymmetric unit. Geometric (I), contact area (I), and stabilization energy (I) parameters were used.

Preparation, characterization and in vitro cytotoxicity study of dronedarone hydrochloride inclusion complexes.

Dronedarone is a new antiarrhythmic drug for the treatment of atrial fibrillation. This study investigated the complexation of dronedarone hydrochloride with β‑cyclodextrin (β-CD) and 2‑hydroxypropil‑β‑CD (HP-β-CD) using three different techniques. The complexes in the solid state were characterized by DSC, TGA, PXRD, FT-IR, SEM and H NMR, demonstrating the formation of the inclusion complexes and exhibiting different properties from the pure drug.

Effect of mono- and dicationic ionic liquids on the viscosity and thermogelation of methylcellulose in the semi-diluted regime.

Thermoreversible hydrogels are suitable in food products in order to improve texture and in biomedical applications as drug delivery vehicles. The properties of hydrogels affect their performance in those applications. In this paper, it is presented the effect of mono- (CMIMBr) and dicationic (C(MIM)Br) imidazolium ionic liquids (ILs) on the viscosity and gelation of methylcellulose (MC) using rheology, micro differential scanning calorimetric and small angle X-ray scattering (SAXS) techniques.

Effect of slight structural changes on the gelation properties of N-phenylstearamide supramolecular gels.

Supramolecular gels present several applications in which the gelator properties are closely dependent on their structure and solvent. Despite this, there are few studies on the effect of the gelation ability of gelators with slight molecular changes. Therefore, N-arylestearamides (in which aryl = phenyl (1), 4-tolyl (2) and 4-acetylphenyl (3)) were evaluated in different solvents.

Impact of Anions on the Partition Constant, Self-Diffusion, Thermal Stability, and Toxicity of Dicationic Ionic Liquids.

Partition constants (), molecular dynamics (, , and DOSY measurements), thermal stability, and toxicity of dicationic ionic liquids (ILs) were determined. The dicationic ILs derived from 1,-bis(3-methylimidazolim-1-yl)octane, [BisOct(MIM)][2X] (in which X = Cl, Br, NO, SCN, BF, and NTf), were evaluated to verify the influence of anion structure on the IL properties. A monocationic IL [Oct(MIM)][Br] was also monitored for comparison.

Insights on the Similarity of Supramolecular Structures in Organic Crystals Using Quantitative Indexes.

The quest for concepts of isostructurality in organic crystals has been long and mostly based on geometric data, even with the development of modern software. This field of study is of great interest to the pharmaceutical industry and for the prediction of crystal structures. Despite this, there is still no methodology that provides broad quantitative and comparable similarity data between two complete crystalline structures.

Heteroassembly Ability of Dicationic Ionic Liquids and Neutral Active Pharmaceutical Ingredients.

Extensive investigation of interactions and aggregation properties of IL + API systems is necessary to apply ionic liquids (ILs) with different hydrophobic characteristics to drug delivery or in active pharmaceutical ingredient (API) formulations. Therefore, this study aims to investigate the heteroassembly between dicationic ILs ([BisOct(MIM)][2X], in which X is Br or BF, and [BisOct(BnIM)][2Br]), both in the absence and the presence of neutral APIs (salicylic acid, ibuprofen, and paracetamol) with different functional groups. Isothermal titration calorimetry results demonstrate that IL-API associations occur at very low concentrations of IL.

Synthesis, effect of substituents on the regiochemistry and equilibrium studies of tetrazolo[1,5-]pyrimidine/2-azidopyrimidines.

An efficient synthesis methodology for a series of tetrazolo[1,5-]pyrimidines substituted at the 5- and 7-positions from the cyclocondensation reaction [CCC + NCN] was developed. The NCN corresponds to 5-aminotetrazole and CCC to β-enaminone. Two distinct products were observed in accordance with the β-enaminone substituent.

Thermodynamic Insights into the Binding of Mono- and Dicationic Imidazolium Surfactant Ionic Liquids with Methylcellulose in the Diluted Regime.

Alkylimidazolium salts are an important class of ionic liquids (ILs) due to their self-assembly capacity when in solution and due to their potential applications in chemistry and materials science. Therefore, detailed knowledge of the physicochemical properties of this class of ILs and their mixtures with natural polymers is highly desired. This work describes the interactions between a homologous series of mono- (CMIMBr) and dicationic imidazolium (C(MIM)Br) ILs with cellulose ethers in aqueous medium.

Regiochemistry of cyclocondensation reactions in the synthesis of polyazaheterocycles.

The syntheses of several polyazaheterocycles are demonstrated. The cyclocondensation reactions between β-enaminodiketones [CClC(O)C(=CNMe)C(O)-COEt] and aromatic amidines resulted in glyoxalate-substituted pyrido[1,2-]pyrimidinone, thiazolo[3,2-]pyrimidinone and pyrimido[1,2-]benzimidazole. Pyrazinones and quinoxalinones were obtained through the reaction of these glyoxalates with ethylenediamine and 1,2-phenylenediamine derivatives.

Preparation of TiO₂ nanoparticles coated with ionic liquids: a supramolecular approach.

Coated TiO2 nanoparticles by dicationic imidazolium-based ionic liquids (ILs) were prepared and studied by differential scanning calorimetry (DSC), dynamic light scattering (DLS), transmission electron microscopy (TEM), powder X-ray diffraction (XRD), and scanning electron microscopy (SEM). Three ILs with different hydrophobicity degrees and structural characteristics were used (IL-1, IL-2, and IL-3). The interaction between IL molecules and the TiO2 surface was analyzed in both solid state and in solution.