Synthesis of Metforminium Succinate by Melting. Crystal Structure, Thermal, Spectroscopic and Dissolution Properties

The reaction by melt mixing at 220 °C of the antihyperglycemic drug metformin hydrochloride 1 with dehydrated sodium succinate yields efficiently the organic salt [MET]2[SUC] 2 (H-MET+= metforminium and SUC2- = succinate). Solid state CPMAS NMR 13C spectroscopy experiments, powder X-ray diffraction and FT-IR results support the formation of the pharmaceutical salt 2 in good yields. Besides, the charged-assisted hydrogen bonding interactions of type N-H…-O(carboxylate) were thoroughly analyzed by single crystal X-Ray diffraction techniques. Thus, the pharmaceutical salt 2 possesses considerable thermal differences when compared to the pure starting reagents. In addition, intrinsic dissolution rate experiments in buffered aqueous solutions at pH= 6.8 showed a sustained-release behavior of the drug in 2 with a constant value of Kint = 0.885 mg/min * cm2.

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Synthesis, Characterization, and Intrinsic Dissolution Studies of Drug–Drug Eutectic Solid Forms of Metformin Hydrochloride and Thiazide Diuretics

Pharmaceutics ◽

10.3390/pharmaceutics13111926 ◽

2021 ◽

Vol 13 (11) ◽

pp. 1926

Author(s):

Guadalupe Coyote-Dotor ◽

José C. Páez-Franco ◽

Daniel Canseco-González ◽

Alejandra Núñez-Pineda ◽

Alejandro Dorazco-González ◽

...

Keyword(s):

Solid State Nmr ◽

Metformin Hydrochloride ◽

Thiazide Diuretics ◽

X Ray Diffraction ◽

Spectroscopy Analysis ◽

Intrinsic Dissolution ◽

X Ray ◽

Dissolution Properties ◽

Binary Eutectic

The mechanochemical synthesis of drug–drug solid forms containing metformin hydrochloride (MET·HCl) and thiazide diuretics hydrochlorothiazide (HTZ) or chlorothiazide (CTZ) is reported. Characterization of these new systems indicates formation of binary eutectic conglomerates, i.e., drug–drug eutectic solids (DDESs). Further analysis by construction of binary diagrams (DSC screening) exhibited the characteristic V-shaped form indicating formation of DDESs in both cases. These new DDESs were further characterized by different techniques, including thermal analysis (DSC), solid state NMR spectroscopy (SSNMR), powder X-ray diffraction (PXRD) and scanning electron microscopy–energy dispersive X-ray spectroscopy analysis (SEM–EDS). In addition, intrinsic dissolution rate experiments and solubility assays were performed. In the case of MET·HCl-HTZ (χMET·HCl = 0.66), we observed a slight enhancement in the dissolution properties compared with pure HTZ (1.21-fold). The same analysis for the solid forms of MET·HCl-CTZ (χMET·HCl = 0.33 and 0.5) showed an enhancement in the dissolved amount of CTZ accompanied by a slight improvement in solubility. From these dissolution profiles and saturation solubility studies and by comparing the thermodynamic parameters (ΔHfus and ΔSfus) of the pure drugs with these new solid forms, it can be observed that there was a limited modification in these properties, not modifying the free energy of the solution (ΔG) and thus not allowing an improvement in the dissolution and solubility properties of these solid forms.

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Structures and physicochemical properties of vortioxetine salts

Acta Crystallographica Section B Structural Science Crystal Engineering and Materials ◽

10.1107/s2052520616010556 ◽

2016 ◽

Vol 72 (5) ◽

pp. 723-732 ◽

Cited By ~ 6

Author(s):

Xinbo Zhou ◽

Xiurong Hu ◽

Suxiang Wu ◽

Jiali Ye ◽

Mengying Sun ◽

...

Keyword(s):

Antidepressant Drug ◽

Drug Candidate ◽

X Ray Diffraction ◽

High Solubility ◽

Scanning Calorimetry ◽

Intrinsic Dissolution ◽

X Ray ◽

Acidic Proton ◽

Water Ph ◽

Ft Ir

In the present work, novel salts of the multimodal antidepressant drug vortioxetine (VT) were crystallized with pharmaceutically acceptable acids, aiming to improve the solubility of VT. The acids for VT were selected based on ΔpKabeing greater than 2 or 3. Salts of hydrobromic acid (HBr), hydrochloric acid (HCl),p-hydroxybenzoic acid (PHBA), saccharin (SAC) and L-aspartic acid (ASP) were reported. All salts were characterized by single-crystal X-ray diffraction, FT–IR, powder X-ray diffraction (PXRD) and differential scanning calorimetry (DSC). The acidic proton is transferred to the secondary N atom on the piperazine ring of VT, forming the charge-assisted hydrogen bond N+—H...X−(X= Cl, Br, O). Solubility and intrinsic dissolution rate (IDR) experiments were carried out in distilled water (pH = 7.0) to compare the solubilities of the salts with that of VT. The VT–ASP–H2O (1:1:2) salt showed 414 times higher solubility and 1722 times faster IDR compared with VT. VT–ASP–H2O (1:1:2) is a high solubility salt that is stable in a slurry experiment at 298 K in 95% ethanol. The experimental data for the VT–ASP–H2O (1:1:2) salt identify it as a promising drug candidate.

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Effect of texture on the intrinsic dissolution behaviour of acetylsalicylic acid and tolbutamide compacts

Journal of Applied Crystallography ◽

10.1107/s0021889807034553 ◽

2007 ◽

Vol 40 (5) ◽

pp. 857-864 ◽

Cited By ~ 6

Author(s):

Mikko Tenho ◽

Jaakko Aaltonen ◽

Paula Heinänen ◽

Leena Peltonen ◽

Vesa-Pekka Lehto

Keyword(s):

Acetylsalicylic Acid ◽

Random Distribution ◽

Preferred Orientation ◽

X Ray Diffraction ◽

Intrinsic Dissolution ◽

X Ray ◽

Dissolution Studies ◽

Dissolution Properties ◽

Dissolution Behaviour ◽

Attachment Energy

Preferred orientation of crystallites,i.e.texture, is a common result when a sample with an irregular habit of particles is compacted to form a tablet. Since texturization alters the random distribution of the crystal planes on the surface of the compacted sample, the dissolution properties of highly texturized tablets could differ from the properties of a tablet with a less preferred orientation. Three batches from both acetylsalicylic acid and tolbutamide were recrystallized using different crystallization parameters to obtain powders with different texturization behaviour. Several X-ray diffraction procedures were used to characterize the texture and other crystallographic properties of the samples. The intrinsic dissolution profiles were measured using the channel flow technique. In addition, the attachment energy of the crystal planes lying on the surface of the compacts was calculated theoretically. The results indicate that the most texturized compacts had a clearly lower intrinsic dissolution rate than the compacts with a lower degree of preferred orientation. By combining the results of the texture measurements with the calculated attachment energy values, the surface energies of the samples could be estimated and the estimated energy values were in agreement with the results of the dissolution studies. Moreover, it was found that by using the results of the texture measurements, the habit of the sample particles can be successfully predicted.

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Enhancement of Chloroprene/Natural/Butadiene Rubber Nanocomposite Properties Using Organoclays and Their Combination with Carbon Black as Fillers

Polymers ◽

10.3390/polym13071085 ◽

2021 ◽

Vol 13 (7) ◽

pp. 1085

Author(s):

Patricia Castaño-Rivera ◽

Isabel Calle-Holguín ◽

Johanna Castaño ◽

Gustavo Cabrera-Barjas ◽

Karen Galvez-Garrido ◽

...

Keyword(s):

Mechanical Properties ◽

Carbon Black ◽

High Performance ◽

Rubber Matrix ◽

Butadiene Rubber ◽

X Ray Diffraction ◽

X Ray ◽

Rubber Blends ◽

Ft Ir ◽

Chloroprene Rubber

Organoclay nanoparticles (Cloisite® C10A, Cloisite® C15) and their combination with carbon black (N330) were studied as fillers in chloroprene/natural/butadiene rubber blends to prepare nanocomposites. The effect of filler type and load on the physical mechanical properties of nanocomposites was determined and correlated with its structure, compatibility and cure properties using Fourier Transformed Infrared (FT-IR), X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA) and rheometric analysis. Physical mechanical properties were improved by organoclays at 5–7 phr. Nanocomposites with organoclays exhibited a remarkable increase up to 46% in abrasion resistance. The improvement in properties was attributed to good organoclay dispersion in the rubber matrix and to the compatibility between them and the chloroprene rubber. Carbon black at a 40 phr load was not the optimal concentration to interact with organoclays. The present study confirmed that organoclays can be a reinforcing filler for high performance applications in rubber nanocomposites.

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Electrospun Nanosystems Based on PHBV and ZnO for Ecological Food Packaging

Polymers ◽

10.3390/polym13132123 ◽

2021 ◽

Vol 13 (13) ◽

pp. 2123

Author(s):

Maria Râpă ◽

Maria Stefan ◽

Paula Popa ◽

Dana Toloman ◽

Cristian Leostean ◽

...

Keyword(s):

Food Packaging ◽

Spin Trapping ◽

X Ray Diffraction ◽

Paramagnetic Resonance ◽

Hno3 Solution ◽

X Ray ◽

Trapping Method ◽

Ft Ir ◽

Doped Zno ◽

Electron Paramagnetic

The electrospun nanosystems containing poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and 1 wt% Fe doped ZnO nanoparticles (NPs) (with the content of dopant in the range of 0–1 wt% Fe) deposited onto polylactic acid (PLA) film were prepared for food packaging application. They were investigated by scanning electron microscopy (SEM), energy dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), antimicrobial analysis, and X-ray photoelectron spectrometry (XPS) techniques. Migration studies conducted in acetic acid 3% (wt/wt) and ethanol 10% (v/v) food simulants as well as by the use of treated ashes with 3% HNO3 solution reveal that the migration of Zn and Fe falls into the specific limits imposed by the legislation in force. Results indicated that the PLA/PHBV/ZnO:Fex electrospun nanosystems exhibit excellent antibacterial activity against the Pseudomonas aeruginosa (ATCC-27853) due to the generation of a larger amount of perhydroxyl (˙OOH) radicals as assessed using electron paramagnetic resonance (EPR) spectroscopy coupled with a spin trapping method.

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A study on using expanded perlite with hydroxyapatite: Reinforced bio-composites

Proceedings of the Institution of Mechanical Engineers Part H Journal of Engineering in Medicine ◽

10.1177/0954411921996565 ◽

2021 ◽

pp. 095441192199656

Author(s):

Erdoğan Karip ◽

Mehtap Muratoğlu

Keyword(s):

Body Fluid ◽

Xrd Analysis ◽

Cold Isostatic Pressing ◽

Expanded Perlite ◽

X Ray Diffraction ◽

Pressing Method ◽

X Ray ◽

Infra Red ◽

Ft Ir

People are exposed to different kinds of diseases or various accidents in life. Hydroxyapatite (HA) has been widely employed for bone treatment applications. In this study, HA was extracted from sheep bones. Bio-composites were doped with 1, 5, and 10 wt.% of expanded perlite and 5 wt.% of ZrO2–MgO-P2O5. The bio-composites were prepared by the cold isostatic pressing method (250 MPa) and sintered at 900°C for 1 h. In order to evaluate the characteristics of the bio-composites, microhardness, density, X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FT-IR), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) analyses were carried out on them. Additionally, the specimens whose characteristics were determined were kept in synthetic body fluid (SBF), and their in vitro behavior was examined. As a result, it was observed that microhardness increased as both the weight and the grain size of the expanded perlite were increased. Calcium silicate, tri-calcium phosphate, and hydroxyapatite were observed in the XRD analysis of all samples, and the formation of apatite structures was increased by addition of ZrO2–MgO–P2O5.

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Synthesis of Magnetic Ferrocene-Containing Polymer with Photothermal Effects for Rapid Degradation of Methylene Blue

Polymers ◽

10.3390/polym13040558 ◽

2021 ◽

Vol 13 (4) ◽

pp. 558

Author(s):

Wenhui Zhu ◽

Caiyun Zhang ◽

Yali Chen ◽

Qiliang Deng

Keyword(s):

Methylene Blue ◽

Photoelectron Spectroscopy ◽

Room Temperature ◽

Degradation Rate ◽

Model Compound ◽

Vibrating Sample Magnetometer ◽

Simulated Sunlight ◽

X Ray Diffraction ◽

X Ray ◽

Ft Ir

Photothermal materials are attracting more and more attention. In this research, we synthesized a ferrocene-containing polymer with magnetism and photothermal properties. The resulting polymer was characterized by Fourier-transform infrared (FT-IR), vibrating sample magnetometer (VSM), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Its photo-thermocatalytic activity was investigated by choosing methylene blue (MB) as a model compound. The degradation percent of MB under an irradiated 808 nm laser reaches 99.5% within 15 min, and the degradation rate is 0.5517 min−1, which is 145 times more than that of room temperature degradation. Under irradiation with simulated sunlight, the degradation rate is 0.0092 min−1, which is approximately 2.5 times more than that of room temperature degradation. The present study may open up a feasible route to degrade organic pollutants.

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Hydrothermal Synthesis, Characterization and Exploration of Photocatalytic Activities of Polyoxometalate: Ni-CoWO4 Nanoparticles

Crystals ◽

10.3390/cryst11050456 ◽

2021 ◽

Vol 11 (5) ◽

pp. 456

Author(s):

Fahad A. Alharthi ◽

Hamdah S. Alanazi ◽

Amjad Abdullah Alsyahi ◽

Naushad Ahmad

Keyword(s):

Electron Microscopy ◽

Hydrothermal Synthesis ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Structure Morphology ◽

Photocatalytic Activities ◽

Ft Ir ◽

Photocatalytic Reactions ◽

Cobalt Tungstate

This study demonstrated the hydrothermal synthesis of bimetallic nickel-cobalt tungstate nanostructures, Ni-CoWO4 (NCW-NPs), and their phase structure, morphology, porosity, and optical properties were examined using X-ray Diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), Scanning electron microscopy- energy dispersive X-ray spectroscopy (SEM-EDS), high resolution Transmission electron microscopy (HR-TEM), Brunauer-Emmett-Teller (BET) and Raman instruments. It was found that as-calcined NCW-NPs have a monoclinic phase with crystal size ~50–60 nm and is mesoporous. It possessed smooth, spherical, and cubic shape microstructures with defined fringe distance (~0.342 nm). The photocatalytic degradation of methylene blue (MB) and rose bengal (RB) dye in the presence of NCW-NPs was evaluated, and about 49.85% of MB in 150 min and 92.28% of RB in 90 min degraded under visible light. In addition, based on the scavenger’s study, the mechanism for photocatalytic reactions is proposed.

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Multidimensional Ln-Aminophthalate Photoluminescent Coordination Polymers

Materials ◽

10.3390/ma14071786 ◽

2021 ◽

Vol 14 (7) ◽

pp. 1786

Author(s):

Carla Queirós ◽

Chen Sun ◽

Ana M. G. Silva ◽

Baltazar de Castro ◽

Juan Cabanillas-Gonzalez ◽

...

Keyword(s):

Water Content ◽

Coordination Polymers ◽

Metal Ion ◽

Low Cost ◽

Microwave Assisted Synthesis ◽

X Ray Diffraction ◽

X Ray ◽

Wide Range ◽

Ft Ir ◽

Ft Ir Spectroscopy

The development of straightforward reproducible methods for the preparation of new photoluminescent coordination polymers (CPs) is an important goal in luminescence and chemical sensing fields. Isophthalic acid derivatives have been reported for a wide range of applications, and in addition to their relatively low cost, have encouraged its use in the preparation of novel lanthanide-based coordination polymers (LnCPs). Considering that the photoluminescent properties of these CPs are highly dependent on the existence of water molecules in the crystal structure, our research efforts are now focused on the preparation of CP with the lowest water content possible, while considering a green chemistry approach. One- and two-dimensional (1D and 2D) LnCPs were prepared from 5-aminoisophthalic acid and Sm3+/Tb3+ using hydrothermal and/or microwave-assisted synthesis. The unprecedented LnCPs were characterized by single-crystal X-ray diffraction (SCRXD), powder X-ray diffraction (PXRD), Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM), and their photoluminescence (PL) properties were studied in the solid state, at room temperature, using the CPs as powders and encapsulated in poly(methyl methacrylate (PMMA) films, envisaging the potential preparation of devices for sensing. The materials revealed interesting PL properties that depend on the dimensionality, metal ion, co-ligand used and water content.

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Efficient adsorption of chlorpyrifos onto modified activated carbon by gamma irradiation; a plausible adsorption mechanism

Zeitschrift für Physikalische Chemie ◽

10.1515/zpch-2020-1765 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Mohamed S. Yahia ◽

Ahmed S. Elzaref ◽

Magdy B. Awad ◽

Ahmed M. Tony ◽

Ahmed S. Elfeky

Keyword(s):

Gamma Irradiation ◽

Area Measurement ◽

Maximum Adsorption Capacity ◽

X Ray Diffraction ◽

X Ray ◽

First Order ◽

Pseudo Second Order ◽

Ft Ir ◽

Pseudo First Order ◽

Kinetics Of

Abstract Commercial Granulated Active Carbon (GAC) has been modified using 10 Gy dose Gamma irradiation (GAC10 Gy) for increasing its ability of air purification. Both, the raw and treated samples were applied for removing Chlorpyrifos pesticide (CPF) from ambient midair. Physicochemical properties of the two materials were characterized by Fourier Transform Infrared (FT-IR) and Raman spectroscopy. The phase formation and microstructure were monitored using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), supported with Energy-Dispersive X-ray (EDX). The Surface area measurement was detected using BET particle size prosometry. Obtained outcomes showed that, the maximum adsorption capacity, given by Langmuir equations, was greatly increased from 172.712 to 272.480 mg/g for GAC and GAC10 Gy, respectively, with high selectivity. The overall removal efficiency of GAC10 Gy was notably comparable to that of the original GAC-sorbent. The present study indicated that, gamma irradiation could be a promising technique for treating GAC and turned it more active in eliminating the pesticides pollutants from surrounding air. The data of equilibrium has been analyzed by Langmuir and Freundlich models, that were considerably better suited for the investigated materials than other models. The process kinetics of CPF adsorbed onto both tested carbon versions were found to obey the pseudo first order at all concentrations with an exception at 70 mg/l using GAC, where, the spontaneous exothermic adsorption of Chlorpyrifos is a strong function for the pseudo-first order (PFO) and pseudo second order (PSO) kinetics.

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