scholarly journals The Usefulness of X-ray Diffraction and Thermal Analysis to Study Dietary Supplements Containing Iron

Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 197
Author(s):  
Izabela Jendrzejewska ◽  
Robert Musioł ◽  
Tomasz Goryczka ◽  
Ewa Pietrasik ◽  
Joanna Klimontko ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Melting Point ◽  
Dietary Supplements ◽  
Polymorphic Form ◽  
Food Supplements ◽  
X Ray Diffraction ◽  
Iron Compounds ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Amorphous Compounds

X-ray powder diffraction (XRPD) and thermal analysis (differential scanning calorimetry/derivative of thermogravimetry (DSC/DTG)) are solid-state techniques that can be successfully used to identify and quantify various chemical compounds in polycrystalline mixtures, such as dietary supplements or drugs. In this work, 31 dietary supplements available on the Polish market that contain iron compounds, namely iron gluconate, fumarate, bisglycinate, citrate and pyrophosphate, were evaluated. The aim of the work was to identify iron compounds declared by the manufacturer as food supplements and to try to verify compliance with the manufacturer’s claims. Studies performed by X-ray and thermal analysis confirmed that crystalline iron compounds (iron (II) gluconate, iron (II) fumarate), declared by the manufacturers, were present in the investigated dietary supplements. Iron (II) bisglycinate proved to be semi-crystalline. However, depending on the composition of the formulation, it was possible to identify this compound in the tested supplements. For amorphous iron compounds (iron (III) citrate and iron (III) pyrophosphate), the diffraction pattern does not have characteristic diffraction lines. Food supplements containing crystalline iron compounds have a melting point close to the melting point of pure iron compounds. The presence of excipients was found to affect the shapes and positions of the endothermic peaks significantly. Widening of endothermic peaks and changes in their position were observed, as well as exothermic peaks indicating crystallization of amorphous compounds. Weight loss was determined for all dietary supplements tested. Analysis of the DTG curves showed that the thermal decomposition of most food supplements takes place in several steps. The results obtained by a combination of both simple, relatively fast and reliable XRPD and DSC/DTG methods are helpful in determining phase composition, pharmaceutical abnormalities or by detecting the presence of the correct polymorphic form.

Structural and thermodynamic properties of nanocrystalline fcc metals prepared by mechanical attrition

1992 ◽  
Vol 7 (7) ◽  
pp. 1751-1761 ◽  
Author(s):  
J. Eckert ◽  
J.C. Holzer ◽  
C.E. Krill ◽  
W.L. Johnson
Keyword(s):  
Thermal Analysis ◽  
Grain Size ◽  
Melting Point ◽  
Grain Boundary ◽  
Bulk Modulus ◽  
Atomic Level ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fcc Metals ◽  
Mechanical Attrition

Nanocrystalline fcc metals have been synthesized by mechanical attrition. The crystal refinement and the development of the microstructure have been investigated in detail by x-ray diffraction, differential scanning calorimetry, and transmission electron microscopy. The deformation process causes a decrease of the grain size of the fcc metals to 6–22 nm for the different elements. The final grain size scales with the melting point and the bulk modulus of the respective metal: the higher the melting point and the bulk modulus, the smaller the final grain size of the powder. Thus, the ultimate grain size achievable by this technique is determined by the competition between the heavy mechanical deformation introduced during milling and the recovery behavior of the metal. X-ray diffraction and thermal analysis of the nanocrystalline powders reveal that the crystal size refinement is accompanied by an increase in atomic-level strain and in the mechanically stored enthalpy in comparison to the undeformed state. The excess stored enthalpies of 10–40% of the heat of fusion exceed by far the values known for conventional deformation processes. The contributions of the atomic-level strain and the excess enthalpy of the grain boundaries to the stored enthalpies are critically assessed. The kinetics of grain growth in the nanocrystalline fcc metals are investigated by thermal analysis. The activation energy for grain boundary migration is derived from a modified Kissinger analysis, and estimates of the grain boundary enthalpy are given.

scholarly journals Mechanochemical Formation of Racemic Praziquantel Hemihydrate with Improved Biopharmaceutical Properties

Pharmaceutics ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 289
Author(s):  
Debora Zanolla ◽  
Dritan Hasa ◽  
Mihails Arhangelskis ◽  
Gabriela Schneider-Rauber ◽  
Michele R. Chierotti ◽  
...  
Keyword(s):  
Dissolution Rate ◽  
Polymorphic Form ◽  
In Vitro Tests ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Experimental Conditions ◽  
Intrinsic Dissolution ◽  
Intrinsic Dissolution Rate ◽  
X Ray ◽  
Enhanced Solubility

Praziquantel (PZQ) is the first-line drug used against schistosomiasis, one of the most common parasitic diseases in the world. A series of crystalline structures including two new polymorphs of the pure drug and a series of cocrystals of PZQ have been discovered and deposited in the Cambridge Structural Database (CSD). This work adds to the list of multicomponent forms of PZQ a relevant example of a racemic hemihydrate (PZQ-HH), obtainable from commercial PZQ (polymorphic Form A) through mechanochemistry. Noteworthy, the formation of the new hemihydrate strongly depends on the initial polymorphic form of PZQ and on the experimental conditions used. The new PZQ-HH has been fully characterized by means of HPLC, Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), Hot-Stage Microscopy (SEM), Powder X-Ray Diffraction (PXRD), Scanning Electron Microscopy (SEM), FT-IR, polarimetry, solid-state NMR (SS-NMR), solubility and intrinsic dissolution rate (IDR), and in vitro tests on Schistosoma mansoni adults. The crystal structure was solved from the powder X-ray diffraction pattern and validated by periodic-DFT calculations. The new bioactive hemihydrate was physically stable for three months and showed peculiar biopharmaceutical features including enhanced solubility and a double intrinsic dissolution rate in water in comparison to the commercially available PZQ Form A.

Synthesis, Characterization and Magnetism of Nanosized Copper Ferrite

2008 ◽  
Vol 368-372 ◽  
pp. 604-606 ◽  
Author(s):  
Wei Zhong Lv ◽  
Zhong Kuang Luo ◽  
Bo Liu ◽  
Xiang Zhong Ren ◽  
Hong Hua Cai ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Copper Ferrite ◽  
Sonochemical Method ◽  
Thermal Gravimetric ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ft Ir ◽  
Scanning Electron

Copper ferrite powders were successfully synthesized by sonochemical method. The resultant powders were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), FT-IR, differential thermal analysis-thermal gravimetric (DTA-TG), differential scanning calorimetry (DSC) and VSM. The particle saturation magnetization (Ms) is 66 emu/g and an intrinsic coercive force (iHc) is 2100 Oe when the precursor calcined at 950 °C for 15 h.

scholarly journals Evaluation of Thermal-Induced Polymorphic Transformation on Desloratadine and Desloratadine-Benzoic Acid Salt

2020 ◽  
Vol 26 (4) ◽  
pp. 399-405
Author(s):  
Ahmad Ainurofiq ◽  
Rachmat Mauludin ◽  
Diky Mudhakir ◽  
Sundani Nurono Soewandhi
Keyword(s):  
Melting Point ◽  
Benzoic Acid ◽  
Polymorphic Transformation ◽  
Heating Process ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Pharmaceutical Ingredients ◽  
Physicochemical Changes ◽  
Transformation Methods

Background: Active pharmaceutical ingredients face a challenge in manufacturing due to adverse physicomechanical properties. Desloratadine (DES) form I exhibits poor mechanical behavior through the formation of capping during the tableting process. Salt formation from DES and benzoic acid (BA) has been observed to resolve poor mechanical properties. However, the ability to withstand heat from the manufacturing process should be implemented in DES and DES-BA salt. The aim of this study was to determine the differences between thermal treatment results on DES and DES-BA salt and whether it causes them to undergo polymorphic transformation. Methods: Salt was crystallized between DES and BA using the solvent evaporation method. DES and DES-BA salt were heated at 110°C, 159°C (melting point of DES), 181°C (melting point of DES-BA), and 190°C. Following this, characterization was performed using differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and solubility testing. Results: Polymorphic transformation caused by heat occurred in DES, but not in DES-BA salt. The transformation of DES was induced by the effect of heating, which changed polymorph I to a mixture of polymorph I and III at 110°C, to polymorph II at 159°C, and to a mixture of polymorph I, II, and III at 190°C. Under 190oC, DES-BA is still stable and did not undergo a polymorphic transformation. However, at 190oC, decomposition started to occur, which implied decreased solubility, which did not occur in DES. Conclusion: The heating process did not cause DES-BA salt to undergo a polymorphic transformation. However, it caused decomposition at 190oC. DES underwent a polymorphic transformation when exposed to the same condition without decomposition. This provided information to always pay attention to temperature during manufacturing processes that include DES or DES-BA salt to avoid physicochemical changes.

Solvates of the antifungal drug griseofulvin: structural, thermochemical and conformational analysis

2013 ◽  
Vol 70 (1) ◽  
pp. 54-62 ◽  
Author(s):  
Srinivasulu Aitipamula ◽  
Pui Shan Chow ◽  
Reginald B. H. Tan
Keyword(s):  
Melting Point ◽  
Solvent Free ◽  
Antifungal Drug ◽  
Free Form ◽  
Solution Stability ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Solvent Molecules ◽  
Solid Form

Four solvates of an antifungal drug, griseofulvin (GF), were discovered. All the solvates were characterized by differential scanning calorimetry, thermogravimetric analysis, and their crystal structures were determined by single-crystal X-ray diffraction. The solvents that form the solvates are acetonitrile, nitromethane and nitroethane (2:1 and 1:1). It was found that all the solvates lose the solvent molecules from the crystal lattice between 343 and 383 K, and that the melting point of the desolvated materials matched the melting point of the solvent-free GF (493 K). The conformation of the GF molecule in solvent-free form was found to be significantly different from the conformations found in the solvates. Solution stability studies revealed that the GF–acetonitrile solvate transforms to GF and that GF–nitroethane (1:1) solvate transforms to GF–nitroethane (2:1) solvate. On the other hand, GF–nitromethane and GF–nitroethane (2:1) solvates were found to be stable in solution. Our results highlight the importance of the co-crystallization technique in the pharmaceutical drug development; it not only expands the solid form diversity but also creates new avenues for unraveling novel solvates.

scholarly journals X-ray and Thermal Analysis of Selected Drugs Containing Acetaminophen

Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 5909
Author(s):  
Izabela Jendrzejewska ◽  
Tomasz Goryczka ◽  
Ewa Pietrasik ◽  
Joanna Klimontko ◽  
Josef Jampilek
Keyword(s):  
Thermal Analysis ◽  
Pharmaceutical Preparations ◽  
Active Pharmaceutical Ingredient ◽  
Polymorphic Form ◽  
Scanning Calorimetry ◽  
Monoclinic System ◽  
X Ray ◽  
Line Intensities ◽  
Diffraction Patterns ◽  
Medicinal Drugs

Studies carried out by X-ray and thermal analysis confirmed that acetaminophen (paracetamol), declared by the manufacturers as an Active Pharmaceutical Ingredient (API), was present in all studied medicinal drugs. Positions of diffraction lines (2θ angles) of the studied drugs were consistent with standards for acetaminophen, available in the ICDD PDF database Release 2008. |Δ2θ| values were lower than 0.2°, confirming the authenticity of the studied drugs. Also, the values of interplanar distances dhkl for the examined samples were consistent with those present in the ICDD. Presence of acetaminophen crystalising in the monoclinic system (form I) was confirmed. Various line intensities for API were observed in the obtained diffraction patterns, indicating presence of the preferred orientation of the crystallites in the examined samples. Thermal analysis of the studied substances confirmed the results obtained by X-ray analysis. Drugs containing only acetaminophen as an API have melting point close to that of pure acetaminophen. It was found that presence of other active and auxiliary substances affected the shapes and positions of endothermal peaks significantly. A broadening of endothermal peaks and their shift towards lower temperatures were observed accompanying an increase in the contents of additional substances being “impurities” in relation to the API. The results obtained by a combination of the two methods, X-ray powder diffraction (XRPD) and differential scanning calorimetry/thermogravimetry (DSC/TGA), may be useful in determination of abnormalities which can occur in pharmaceutical preparations, e.g., for distinguishing original drugs and forged products, detection of the presence of a proper polymorphic form or too low content of the active substance in the investigated drug.

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.

scholarly journals Crystal Structures and Thermal Properties of L-MnC4H4O6•2H2O and DL-MnC4H4O6•2H2O

2019 ◽  
Vol 12 (1) ◽  
pp. 78
Author(s):  
Takanori Fukami ◽  
Shuta Tahara ◽  
Arbi Dimyati
Keyword(s):  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Room Temperature ◽  
Structural Parameters ◽  
Silica Gels ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Weight Losses ◽  
Group Symmetries

Manganese L-tartrate dihydrate, L-MnC4H4O6·2H2O, and manganese DL-tartrate dihydrate, DL-MnC4H4O6·2H2O, crystals were grown at room temperature by the gel method using silica gels as the growth medium. Differential scanning calorimetry, thermogravimetric-differential thermal analysis, and X-ray diffraction measurements were performed on both crystals. The space group symmetries (monoclinic P21 and P2/c) and structural parameters of the crystals were determined at room temperature. Both structures consisted of slightly distorted MnO6 octahedra, C4H4O6 and H2O molecules, and O–H···O hydrogen-bonding frameworks between adjacent molecules. Weight losses due to thermal decomposition of the crystals were found to occur in the temperature range of 300–1150 K. We inferred that the weight losses were caused by the evaporation of bound 2H2O molecules, and the evolutions of gases from C4H4O4 and of (1/2)O2 gas from MnO2, and that the residual black substance left in the vessels after decomposition was manganese oxide (MnO).

Effect of Cooling Rates on the Solidification and Microstructure of Rapidly Solidified Mg70.8Zn28Nd1.2 Quasicrystal Alloy

2017 ◽  
Vol 898 ◽  
pp. 246-253
Author(s):  
Xing Jing Ge ◽  
Xin Ying Teng ◽  
Shu Min Xu ◽  
Jin Yang Zhang
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Thermal Analysis ◽  
Energy Dispersive Spectrometer ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Cooling Rates ◽  
X Ray ◽  
Rapidly Solidified ◽  
Scanning Electron

The influence of cooling rates on the solidification and microstructure of rapidly solidified quasicrystal alloy Mg70.8Zn28Nd1.2(at.%) was investigated. The microstructure, phase constitution, phase transition and phase structure of the alloys were examined by means of scanning electron microscopy, x-ray diffraction, energy dispersive spectrometer, differential scanning calorimetry. The experimental results showed that the phase composition of as-cast Mg70.8Zn28Nd1.2 alloy includes quasicrystal I-phase and Mg7Zn3 phase. For the rapidly solidified alloy ribbons, when the speed is not higher than 400 r/min, the microstructure includes I-phase, Mg7Zn3 phase and α-Mg phase. When the speed is at the range of 400-2000r/min, the Mg7Zn3 phase disappears and only quasicrystal with α-Mg phase exist. With the increase of cooling rate, the grain size decreases and there are a large number of microcrystals in the microstructure. When the speed reaches higher than 2500 r/min, amorphous phase appeared. Differential thermal analysis showed that quasicrystal exist at about 340°C.

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