scholarly journals Improved Solubility of Vortioxetine Using C2-C4 Straight-Chain Dicarboxylic Acid Salt Hydrates

Crystals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 352 ◽  
Author(s):  
Lei Gao ◽  
Xian-Rui Zhang ◽  
Shao-Ping Yang ◽  
Juan-Juan Liu ◽  
Chao-Jie Chen
Keyword(s):  
Dicarboxylic Acid ◽  
Crystal Engineering ◽  
Dicarboxylic Acids ◽  
Acid Salt ◽  
X Ray Diffraction ◽  
Straight Chain ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Salt Hydrates ◽  
Aliphatic Dicarboxylic Acids

The purpose of this study was to improve the solubility of vortioxetine by crystal engineering principles. In this paper, three C2-C4 straight-chain dicarboxylic acid salt hydrates of vortioxetine (VOT-OA, VOT-MA-H2O, and VOT-SUA-H2O, VOT = vortioxetine, OA = Oxalic acid, MA = malonic acid, SUA = succinic acid) were synthesized and characterized by single X-ray diffraction, powder X-ray diffraction, and differential scanning calorimetry. The single crystal structure of three salts reveals that vortioxetine has torsional flexibility, which can encourage VOT to allow combination with aliphatic dicarboxylic acids through N+-H···O hydrogen bonds. The solubility of all salts exhibits a dramatic increase in distilled water, especially for VOT-MA-H2O salt, where it shows the highest solubility, by 96-fold higher compared with pure vortioxetine.

scholarly journals Multi-Component Crystals of 2,2′-Bipyridine with Aliphatic Dicarboxylic Acids: Melting Point-Structure Relations

Crystals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1151
Author(s):  
Vhukhudo Nethanani ◽  
Eustina Batisai
Keyword(s):  
Melting Point ◽  
Dicarboxylic Acids ◽  
Conformation Analysis ◽  
Solvent Evaporation Method ◽  
X Ray Diffraction ◽  
Melting Points ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Aliphatic Dicarboxylic Acids ◽  
The Relationship

The aim of the study was to investigate the relationship between the melting point and the supramolecular structure of three multi-component crystals of aliphatic dicarboxylic acids with 2,2′-bipyridine and to investigate the conformations of 2,2′-bipyridine in published multi-component crystals. The crystals were prepared using the solvent evaporation method and were characterized using single-crystal X-ray diffraction (SCXRD), powder X-ray diffraction (PXRD), and differential scanning calorimetry (DSC). The crystal structures were further analyzed using CrystalExplorer, and the results were correlated with the melting points. The results of the conformation analysis of the reported multi-component crystals of 2,2′-bipyridine are also presented.

Preparation and properties of optically active aromatic polyamides derived from newly prepared chiral phenylindanediamine

1995 ◽  
Vol 7 (2) ◽  
pp. 149-156
Author(s):  
Atsushi Morikawa ◽  
Masa-Aki Kakimoto ◽  
Yoshio Imai
Keyword(s):  
Glass Transition ◽  
Physical Properties ◽  
Dicarboxylic Acid ◽  
Dicarboxylic Acids ◽  
Optically Active ◽  
The Self ◽  
X Ray Diffraction ◽  
X Ray ◽  
Aromatic Polyamides ◽  
Circular Dichroïsm

Chiral phenylindanediamnine (+)-2 was synthesized starting from chiral phenyl-indanedicarboxylic acid by a Schmidt rearrangement. Ordered amine-acid AB-type monomers, 8 and 9, were also prepared by a controlled reaction of (+)-2 with diacid chlorides. Disordered and ordered polyamides were synthesized by the reaction of (+)-2 with dicarboxylic acids, and the self-condensation of 8 and 9, respectively. Both the ordered and disordered polyamides were soluble in various solvents. The polyamides composed of the same dicarboxylic acid prepared by the different routes showed the same circular dichroism spectra. X-ray diffraction of the polyamide films indicated that all of the polyamides were amorphous. The glass transition and decomposition temperatures ranged from 170 to 340°C and from 320 to 400 °C, respectively. Additionally, polyamides containing the same diacids displayed nearly equivalent physical properties.

scholarly journals Melting Diagrams of Adefovir Dipivoxil and Dicarboxylic Acids: An Approach to Assess Cocrystal Compositions

Crystals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 70 ◽  
Author(s):  
Hyunseon An ◽  
Insil Choi ◽  
Il Kim
Keyword(s):  
Solid State ◽  
Adefovir Dipivoxil ◽  
Sufficient Conditions ◽  
Dicarboxylic Acids ◽  
Current Approach ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Pharmaceutical Ingredients ◽  
Solution Crystallization

Pharmaceutical cocrystallization is a useful method to regulate the physical properties of active pharmaceutical ingredients (APIs). Since the cocrystals may form in various API/coformer ratios, identification of the cocrystal composition is the critical first step of any further analysis. However, the composition identification is not always unambiguous if cocrystallization is performed in solid state with unsuccessful solution crystallization. Single melting point and some new X-ray diffraction peaks are necessary but not sufficient conditions. In the present study, the use of melting diagrams coupled with the X-ray diffraction data was tested to identify cocrystal compositions. Adefovir dipivoxil (AD) was used as a model API, and succinic acid (SUC), suberic acid (SUB), and glutaric acid (GLU) were coformers. Compositions of AD/SUC and AD/SUB had been previously identified as 2:1 and 1:1, but that of AD/GLU was not unambiguously identified because of the difficulty of solution crystallization. Melting diagrams were constructed with differential scanning calorimetry, and their interpretation was assisted by powder X-ray diffraction. The cocrystal formation was exhibited as new compositions with congruent melting in the phase diagrams. This method correctly indicated the previously known cocrystal compositions of AD/SUC and AD/SUB, and it successfully identified the AD/GLU cocrystal composition as 1:1. The current approach is a simple and useful method to assess the cocrystal compositions when the crystallization is only possible in solid state.

scholarly journals Preparation of Progesterone Co-Crystals Based on Crystal Engineering Strategies

Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3936 ◽  
Author(s):  
Huahui Zeng ◽  
Jing Xiong ◽  
Zhuang Zhao ◽  
Jingyi Qiao ◽  
Duanjie Xu ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Ir Spectroscopy ◽  
Crystal Engineering ◽  
Slow Evaporation ◽  
X Ray Diffraction ◽  
Dihydroxybenzoic Acid ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Positive Support ◽  
Selection Of

Three co-formers of 2-chloro-4-nitroaniline (CNA), 2,5-dihydroxybenzoic acid (DHB), and 4,4′-biphenol (DOD) were selected to prepare the co-crystal of progesterone (PROG) based on crystal engineering strategies. These co-crystals were successfully obtained via slow evaporation from different solutions and were characterized by single-crystal X-ray diffraction spectroscopy, powder X-ray diffraction, IR spectroscopy, and differential scanning calorimetry. Different binding networks were observed in the co-crystal structures of PROG. The PROG-CNA co-crystal had the fastest rates and highest concentrations of PROG in PBS solution compared with PROG or other co-crystals in the dissolution experiments. This might be attributable to more stable and abundant interactions between the PROG and CNA molecules. Our investigations provide positive support for the selection of suitable co-formers using crystal engineering strategies.

scholarly journals Coordination Polymers Constructed from Semi-Rigid N,N′-Bis(3-pyridyl)terephthalamide and Dicarboxylic Acids: Effect of Ligand Isomerism, Flexibility, and Identity

Chemistry ◽  
2020 ◽  
Vol 3 (1) ◽  
pp. 1-12
Author(s):  
Chia-Jou Chen ◽  
Chia-Ling Chen ◽  
Yu-Hsiang Liu ◽  
Wei-Te Lee ◽  
Ji-Hong Hu ◽  
...  
Keyword(s):  
Dicarboxylic Acid ◽  
Coordination Polymers ◽  
Three Dimensional ◽  
Dicarboxylic Acids ◽  
Zigzag Chain ◽  
X Ray Diffraction ◽  
Marked Contrast ◽  
One Dimensional ◽  
X Ray ◽  
Amide Ligands

Reactions of the semi-rigid N,N′-bis(3-pyridyl)terephthalamide (L) with divalent metal salts in the presence of dicarboxylic acids afforded [Cd(L)0.5(1,2-BDC)(H2O)]n (1,2-H2BDC = benzene-1,2-dicarboxylic acid), 1, {[Cd(L)1.5(1,3-BDC)(H2O)]·5H2O}n (1,3-H2BDC = benzene-1,3-dicarboxylic acid), 2a, {[Cd(1,3-BDC)(H2O)3]·2H2O}n, 2b, {[Cd(L)0.5(1,4-BDC)(H2O)2]·H2O}n (1,4-H2BDC = benzene-1,4-dicarboxylic acid), 3, and [Cu(L)0.5(5-tert-IPA)]n (5-tert-IPA = 5-tert-butylbenzene-1,3-dicarboxylic acid), 4, which have been structurally characterized by single crystal X-ray diffraction. Complexes 1 and 3 are two-dimensional (2D) layers with the bey and the hcb topologies, and 2a and 2b are one-dimensional (1D) ladder and zigzag chain, respectively, while 4 shows a 3-fold interpenetrated three-dimensional (3D) net with the cds topology. The structures of these coordination polymers containing the semi-rigid L ligands are subject to the donor atom positions and the identity of the dicarboxylate ligands, which are in marked contrast to those obtained from the flexible bis-pyridyl-bis-amide ligands that form self-catenated nets. The luminescence of 1 and 3 and thermal properties of complexes 1, 3, and 4 are also discussed.

Studies on the Preparation, Characterization and Solubility of -Cyclodextrin-Roxythromycin Inclusion Complexes

2009 ◽  
Vol 2 (2) ◽  
pp. 523-530
Author(s):  
D. Nagasamy Venkatesh ◽  
S. Karthick ◽  
M. Umesh ◽  
G. Vivek ◽  
R.M. Valliappan ◽  
...  
Keyword(s):  
Dissolution Rate ◽  
Inclusion Complexes ◽  
Phase Solubility ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ir Studies ◽  
Poorly Soluble ◽  
Poorly Soluble Drug

Roxythromycin/ β-cyclodextrin (Roxy/ β-CD) dispersions were prepared with a view to study the influence of β-CD on the solubility and dissolution rate of this poorly soluble drug. Phase-solubility profile indicated that the solubility of roxythromycin was significantly increased in the presence of β-cyclodextrin and was classified as AL-type, indicating the 1:1 stoichiometric inclusion complexes. Physical characterization of the prepared systems was carried out by differential scanning calorimetry (DSC), X-ray diffraction studies (XRD) and IR studies. Solid state characterization of the drug β-CD binary system using XRD, FTIR and DSC revealed distinct loss of drug crystallinity in the formulation, ostensibly accounting for enhancement of dissolution rate.

scholarly journals A review of nanotechnology with an emphasis on Nanoplex

2015 ◽  
Vol 51 (2) ◽  
pp. 255-263
Author(s):  
Rupali Nanasaheb Kadam ◽  
Raosaheb Sopanrao Shendge ◽  
Vishal Vijay Pande
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Drug Loading ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Conventional Drug ◽  
Anionic Drugs ◽  
Oppositely Charged ◽  
The Brain

<p>The use of nanotechnology based on the development and fabrication of nanostructures is one approach that has been employed to overcome the challenges involved with conventional drug delivery systems. Formulating Nanoplex is the new trend in nanotechnology. A nanoplex is a complex formed by a drug nanoparticle with an oppositely charged polyelectrolyte. Both cationic and anionic drugs form complexes with oppositely charged polyelectrolytes. Compared with other nanostructures, the yield of Nanoplex is greater and the complexation efficiency is better. Nanoplex are also easier to prepare. Nanoplex formulation is characterized through the production yield, complexation efficiency, drug loading, particle size and zeta potential using scanning electron microscopy, differential scanning calorimetry, X-ray diffraction and dialysis studies. Nanoplex have wide-ranging applications in different fields such as cancer therapy, gene drug delivery, drug delivery to the brain and protein and peptide drug delivery.</p>

scholarly journals Diethylstilbestrol Modifies the Structure of Model Membranes and Is Localized Close to the First Carbons of the Fatty Acyl Chains

Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 220
Author(s):  
Alessio Ausili ◽  
Inés Rodríguez-González ◽  
Alejandro Torrecillas ◽  
José A. Teruel ◽  
Juan C. Gómez-Fernández
Keyword(s):  
Membrane Surface ◽  
Water Layer ◽  
Fatty Acyl ◽  
31P Nmr Spectroscopy ◽  
Relaxation Rates ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Acyl Chains ◽  
Dynamics Simulations

The synthetic estrogen diethylstilbestrol (DES) is used to treat metastatic carcinomas and prostate cancer. We studied its interaction with membranes and its localization to understand its mechanism of action and side-effects. We used differential scanning calorimetry (DSC) showing that DES fluidized the membrane and has poor solubility in DMPC (1,2-dimyristoyl-sn-glycero-3-phosphocholine) in the fluid state. Using small-angle X-ray diffraction (SAXD), it was observed that DES increased the thickness of the water layer between phospholipid membranes, indicating effects on the membrane surface. DSC, X-ray diffraction, and 31P-NMR spectroscopy were used to study the effect of DES on the Lα-to-HII phase transition, and it was observed that negative curvature of the membrane is promoted by DES, and this effect may be significant to understand its action on membrane enzymes. Using the 1H-NOESY-NMR-MAS technique, cross-relaxation rates for different protons of DES with POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine) protons were calculated, suggesting that the most likely location of DES in the membrane is with the main axis parallel to the surface and close to the first carbons of the fatty acyl chains of POPC. Molecular dynamics simulations were in close agreements with the experimental results regarding the location of DES in phospholipids bilayers.

scholarly journals Effects of Sintering Temperature on Densification, Microstructure and Mechanical Properties of Al-Based Alloy by High-Velocity Compaction

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 218
Author(s):  
Xianjie Yuan ◽  
Xuanhui Qu ◽  
Haiqing Yin ◽  
Zaiqiang Feng ◽  
Mingqi Tang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Velocity ◽  
Sintered Density ◽  
Sintering Temperature ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transmission Electron ◽  
High Velocity Compaction ◽  
Sintered Temperature

This present work investigates the effects of sintering temperature on densification, mechanical properties and microstructure of Al-based alloy pressed by high-velocity compaction. The green samples were heated under the flow of high pure (99.99 wt%) N2. The heating rate was 4 °C/min before 315 °C. For reducing the residual stress, the samples were isothermally held for one h. Then, the specimens were respectively heated at the rate of 10 °C/min to the temperature between 540 °C and 700 °C, held for one h, and then furnace-cooled to the room temperature. Results indicate that when the sintered temperature was 640 °C, both the sintered density and mechanical properties was optimum. Differential Scanning Calorimetry, X-ray diffraction of sintered samples, Scanning Electron Microscopy, Energy Dispersive Spectroscopy, and Transmission Electron Microscope were used to analyse the microstructure and phases.

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