An attempt to chemically state the cross-talk between monomers of COX homodimers by double/hybrid inhibitors mofezolac-spacer-mofezolac and mofezolac-spacer-arachidonic acid.

Cardiovascular diseases (CVDs) account for over 17 million death globally each year, including arterial thrombosis. Platelets are key components in the pathogenesis of this disease and modulating their activity is an effective strategy to treat such thrombotic events. Cyclooxygenase-1 (COX-1) isoenzyme is involved in platelet activation and is the main target of non-steroidal anti-inflammatory drugs (NSAIDs) and new selective inhibitor research. Inhibitors of general formula mofezolac-spacer-mofezolac (mof-spacer-mof) and mofezolac-spacer-arachidonic acid (mof-spacer-AA) were projected to investigate the possible cross-talk between the two monomers (Eallo and Ecat) forming the COX-1 homodimer. Mofezolac was chosen as either one or two moieties of these molecules being the known most potent and selective COX-1 inhibitor and administrated to humans as Disopain™, then arachidonic acid (AA) was used to develop molecules bearing, in the same compound, in addition to the inhibitor moiety (mofezolac) also the natural COX substrate. Depending on the nature of the spacer, COX-1 and COX-2 activity was differently inhibited by mof-spacer-mof set with a preferential COX-1 inhibition. The highest COX-1 selectivity was exhibited by the compound in which the spacer was the benzidine [N,N'-(biphenyl-4,4'-di-yl)bis (2-[3,4-bis(4-methoxyphenyl)isoxazol-5-yl]acetamide) (15): COX-1 IC50 = 0.08 µM, COX-2 IC50 > 50 µM, Selectivity Index (SI) > 625]. In the case of mof-spacer-AA set, the COX inhibitory potency and also the isoform preference changed. (5Z, 8Z, 11Z, 14Z)-N-(4-{2-[3,4-Bis(4-methoxyphenyl)isoxazol-5-yl]acetamido}butyl)icosa-5,8,11,14-tetraenamide (19) and (5Z, 8Z, 11Z, 14Z)-N-(4'-{2-[3,4-bis(4-methoxyphenyl)isoxazol-5-yl]acetamido}-[1,1'-biphenyl]-4-yl)icosa-5,8,11,14-tetraenamide (21), in which the spacer is the 1,2-diaminobutane or benzidine, respectively, selectively inhibited the COX-2, whereas when the spacer is the 1,4-phenylendiamine [(5Z, 8Z, 11Z, 14Z)-N-(4-{2-[3,4-bis(4-methoxyphenyl)isoxazol-5-yl]acetamido}phenyl)icosa-5,8,11,14-tetraenamide) (20) the COX preference is COX-1 (COX-1 IC50 = 0.05 µM, COX-2 IC50 > 50 µM, with a COX-1 selectivity > 1000). Molecular modelling by using FLAP algorithm shows fundamental interactions of the novel compounds at the entry channel of COX and inside its catalytic cavity. The effect of these mof-spacer-mof and mof-spacer-AA in inhibiting in vitro free arachidonic acid-induced platelet aggregation was also determined. A positive profile of hemocompatibility in relation to their influence on the blood coagulation cascade and erythrocyte toxicity was observed. Cytotoxicity and genotoxicity safety were also found for these two novel sets of compounds.

Effects of a novel roflumilast and formoterol fumarate dry powder inhaler formulation in experimental allergic asthma.

In this study we aimed to develop a roflumilast (R) and formoterol fumarate (F) dry powder inhaler formulation (DPI) incorporating HPßCD by spray drying and evaluated if it attenuates the inflammatory process and improves lung function in a murine model of ovalbumin induced allergic asthma. The DPI was characterized by powder X-ray diffraction, thermal analysis, scanning electron microscopy, particle size, density, specific surface area and dynamic vapor sorption analyses. In vitro deposition studies were performed using a NGI, while transepithelial permeability and in vivo effects on lung mechanics and inflammation in a model of allergic asthma were also assessed. The R:F formulation was amorphous with high glass transition temperatures, comprised of wrinkled particles, had low bulk and tapped densities, high surface area, suitable particle size for pulmonary delivery and exhibited no recrystallization even at high relative humidities. MMAD were statistically similar of 4.22 ± 0.19 and 4.32 ± 0.13 µm for F and R, respectively. Fine particle fractions (<5 µm) were of more than 50% of the emitted dose. The R:F formulation led to reduced eosinophil infiltration and airway collagen fiber content, yielding decreased airway hyperresponsiveness. In the current asthma model, the R:F formulation combination decreased inflammation and remodeling, thus improving lung mechanics.

Development of a new formulation of roflumilast for pulmonary drug delivery to treat inflammatory lung conditions.

The aim of this study was to develop roflumilast dry powder inhaler (DPI) formulations by spray drying using hydroxypropyl-ß-cyclodextrin (HPßCD) and to determine their suitability for pulmonary delivery. Different feed solution concentrations, solvent systems and spray drying parameters were used to obtain the formulations which were characterized using X-ray powder diffraction, thermal analysis, scanning electron microscopy, particle size distribution, bulk and tapped density, specific surface area, dynamic vapour sorption, in vitro deposition properties using a Next Generation Impactor (NGI) and transepithelial permeability. Microparticles spray dried from ethanol were wrinkled and amorphous, exhibiting high glass transition temperatures while those from methanol:n-butyl acetate consisted of irregularly shaped porous particles partially crystalline. All formulations presented low density, particle size and residual solvent content exhibiting high depositon in the lower stages of the NGI. Mass median aerodynamic diameters (MMADs) were in the range of 3.32-4.49 µm, with high fine particle fractions (FPF < 5 µm). Stability studies demonstrated no significant modifications in the solid-state nature and in the aerolisation performance of the selected formulation which presented a Papp of 8.73 × 10-6 ±â€¯4.70 × 10-7 cm/s. The developed roflumilast DPI formulations have potential therapeutic applications in the treatment of lung diseases.

Synthesis and evaluation of the cytotoxic activity of Furanaphthoquinones tethered to 1H-1,2,3-triazoles in Caco-2, Calu-3, MDA-MB231 cells.

Naphthoquinones and 1,2,3-triazoles are structural pharmacophore that is known to impart several cancer cells. This work shows a synthetic methodology to obtain hybrid molecules involving naphthoquinone and triazol scaffold as multiple ligands. A simple and efficient synthetic route was used to prepare a series of sixteen compounds being eight 2-(1-aryl-1H-1,2,3-triazol-4-yl)-2,3-dihydronaphtho[1,2 b]furan-4,5-diones and eight 2-(1-aryl-1H-1,2,3-triazol-4-yl)-2,3-dihydronaphtho[2,3-b]furan-4,9-diones. These compounds were tested in MDA-MB231, Caco-2 and Calu-3 human cancer cells, and among them 7a was the most selective compound on Caco-2 cells, the most sensitized cell line in this study. In silico study suggest that the blockage of topoisomerase I and IIα may be one of the mechanisms of action responsible for the cytotoxic effect of 7a in Caco-2 cells.

Development and Characterization of Dapsone Cocrystal Prepared by Scalable Production Methods.

In this study, the formation of caffeine/dapsone (CAF/DAP) cocrystals by scalable production methods, such as liquid-assisted grinding (LAG) and spray drying, was investigated in the context of the potential use of processed cocrystal powder for pulmonary delivery. A CAF/DAP cocrystal (1:1 M ratio) was successfully prepared by slow evaporation from both acetone and ethyl acetate. Acetone, ethyl acetate, and ethanol were all successfully used to prepare cocrystals by LAG and spray drying. The powders obtained were characterized by X-ray diffractometry (XRD), differential scanning calorimetry (DSC), thermogravimetry (TGA), and Fourier transform infrared spectroscopy (FTIR). Laser diffraction analysis indicated a median particle size (D50) for spray-dried powders prepared from acetone, ethanol, and ethyl acetate of 5.4 ± 0.7, 5.2 ± 0.1, and 5.1 ± 0.0 µm respectively, which are appropriate sizes for pulmonary delivery by means of a dry powder inhaler. The solubility of the CAF/DAP cocrystal in phosphate buffer pH 7.4, prepared by spray drying using acetone, was 506.5 ± 31.5 µg/mL, while pure crystalline DAP had a measured solubility of 217.1 ± 7.8 µg/mL. In vitro cytotoxicity studies using Calu-3 cells indicated that the cocrystals were not toxic at concentrations of 0.1 and of 1 mM of DAP, while an in vitro permeability study suggested caffeine may contribute to the permeation of DAP by hindering the efflux effect. The results obtained indicate that the CAF/DAP cocrystal, particularly when prepared by the spray drying method, represents a possible suitable approach for inhalation formulations with applications in pulmonary pathologies.