scholarly journals Preparation and Characterization of a Novel Cocrystal of Atorvastatin Calcium with Succinic Acid Coformer

2019 ◽  
Vol 19 (3) ◽  
pp. 660
Author(s):  
Yudi Wicaksono ◽  
Dwi Setyawan ◽  
Siswandono Siswandono ◽  
Tri Agus Siswoyo
Keyword(s):  
Succinic Acid ◽  
Dissolution Rate ◽  
Intermolecular Hydrogen Bond ◽  
Acid Amide ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Atorvastatin Calcium ◽  
Hydrogen Bond Interactions

Preparation and characterization of a novel cocrystal of atorvastatin calcium with succinic acid coformer were successfully performed. This research aims to modify the crystalline form of atorvastatin calcium through cocrystallization with succinic acid coformer. The cocrystal was prepared by a solvent evaporation method and characterized by Powder X-Ray Diffraction (PXRD), Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). The atorvastatin calcium-succinic acid cocrystal has new crystalline peaks at 2θ of 12.9, 18.2 and 26.7° indicating the formation of a new crystalline phase. The cocrystal showed the melting point at 205.7 °C with an enthalpy of fusion 30.2 J/g which is different from the initial components. The FTIR spectra of cocrystal showed the shifting of absorption peaks of groups of initial components indicating of formation of atorvastatin calcium-succinic acid cocrystal through acid–amide intermolecular hydrogen bond interactions. The solubility and dissolution test showed that the cocrystal has solubility and dissolution rate significantly higher than the solubility and dissolution rate of pure atorvastatin calcium.

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.

Synthesis of ReItricarbonyl complexes with various sulfur- and oxygen-donating ligands: crystal structures of two ReIdinuclear structures bridged by S atoms

2018 ◽  
Vol 74 (10) ◽  
pp. 1116-1122
Author(s):  
Pheello I. Nkoe ◽  
Hendrik G. Visser ◽  
Chantel Swart ◽  
Alice Brink ◽  
Marietjie Schutte-Smith
Keyword(s):  
Hydrogen Bond ◽  
Intermolecular Hydrogen Bond ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
Metal Centre ◽  
Pyridine Ligand ◽  
X Ray ◽  
Hydrogen Bond Interactions ◽  
Mononuclear Complexes

The synthesis and characterization of two dinuclear complexes, namelyfac-hexacarbonyl-1κ3C,2κ3C-(pyridine-1κN)[μ-2,2′-sulfanediyldi(ethanethiolato)-1κ2S1,S3:2κ3S1,S2,S3]dirhenium(I), [Re2(C4H8S3)(C5H5N)(CO)6], (1), and tetraethylammoniumfac-tris(μ-2-methoxybenzenethiolato-κ2S:S)bis[tricarbonylrhenium(I)], (C8H20N)[Re2(C7H7OS)3(CO)6], (2), together with two mononuclear complexes, namely (2,2′-bithiophene-5-carboxylic acid-κ2S,S′)bromidotricarbonylrhenium(I), (3), and bromidotricarbonyl(methyl benzo[b]thiophene-2-carboxylate-κ2O,S)rhenium(I), (4), are reported. Crystals of (1) and (2) were characterized by X-ray diffraction. The crystal structure of (1) revealed two Re—S—Re bridges. The thioether S atom only bonds to one of the ReImetal centres, while the geometry of the second ReImetal centre is completed by a pyridine ligand. The structure of (2) is characterized by three S-atom bridges and an Re...Re nonbonding distance of 3.4879 (5) Å, which is shorter than the distance found for (1) [3.7996 (6)/3.7963 (6) Å], but still clearly a nonbonding distance. Complex (1) is stabilized by six intermolecular hydrogen-bond interactions and an O...O interaction, while (2) is stabilized by two intermolecular hydrogen-bond interactions and two O...π interactions.

scholarly journals ENHANCEMENT OF GLIBENCLAMIDE DISSOLUTION RATE BY SOLID DISPERSION METHOD USING HPMC AND PVP

2019 ◽  
pp. 19-24 ◽  
Author(s):  
ARIF BUDIMAN ◽  
IYAN SOPYAN ◽  
DENIA SEPTY RIYANDI
Keyword(s):  
Dissolution Rate ◽  
Solid Dispersion ◽  
Solid Dispersions ◽  
Hydroxypropyl Methylcellulose ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Rate Test ◽  
Ft Ir

Objective: The aim of this study was to investigate the effects of changing in the proportions of the solid dispersion formula on the dissolution rate of glibenclamide. Methods: Solid dispersions were prepared by solvent evaporation method by using methanol as solvent, hydroxypropyl methylcellulose (HPMC) and polyvinyl pyrrolidone (PVP) as polymers. The prepared product was evaluated by the saturated solubility test and the dissolution rate test. The prepared product was characterized by Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), and powder X-ray diffraction (PXRD) and Scanning Electron Microscopy (SEM). Results: The result showed solid dispersion with a ratio of glibenclamide: PVP: HPMC (1: 3: 6) has the highest increase in solubility (20 fold) compared to pure glibenclamide. This formula also showed an improvement in dissolution rate from 19.9±1.19% (pure glibenclamide) to 99±1.60% in 60 min. Characterization of FT-IR showed that no chemical reaction occurred in solid dispersion of glibenclamide. The results of X-ray diffraction analysis showed an amorphous form in all solid dispersion formulas. The results of DSC analysis showed that endothermic peak melting point of solid dispersion occurred, and the morphology of solid dispersion was more irregular than pure glibenclamide based on SEM characterization Conclusion: The solid dispersion of glibenclamide using PVP: HPMC as carriers can increase the solubility and dissolution rate compared to pure glibenclamide.

scholarly journals Improved Solubility and Dissolution Rates in Novel Multicomponent Crystals of Piperine with Succinic Acid

2020 ◽  
Vol 88 (2) ◽  
pp. 21
Author(s):  
Erizal Zaini ◽  
Afriyani ◽  
Lili Fitriani ◽  
Friardi Ismed ◽  
Ayano Horikawa ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Succinic Acid ◽  
Dissolution Rate ◽  
Physical Stability ◽  
Channel Structure ◽  
Molar Ratio ◽  
Crystal Formation ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray

The objectives of this study were to prepare and characterize a novel piperine–succinic acid multicomponent crystal phase and to evaluate the improvement in the solubility and dissolution rate of piperine when prepared in the multicomponent crystal formation. The solid-state characterization of the novel multicomponent crystal was performed by powder X-ray diffraction (XRD), differential scanning calorimetry (DSC), and Fourier transform-infrared (FT-IR) spectroscopy. Solubility and dissolution rate profiles were evaluated in distilled water. The physical stability was evaluated under high relative humidity (75% and 100% RH). The determination of the single crystal X-ray diffraction structure revealed that this novel multicomponent crystal was a cocrystalline phase of piperine–succinic acid (2:1 molar ratio). The differential scanning calorimetry thermogram of the cocrystal showed a single and sharp endothermic peak at 110.49 °C. The cocrystal resulted in greater solubility and a faster dissolution rate of piperine than intact piperine. This improvement was a result of the formation of a channel structure in the cocrystal. In addition, the cocrystal was stable under a humid condition.

scholarly journals Acemetacin cocrystals and salts: structure solution from powder X-ray data and form selection of the piperazine salt

IUCrJ ◽  
2014 ◽  
Vol 1 (2) ◽  
pp. 136-150 ◽  
Author(s):  
Palash Sanphui ◽  
Geetha Bolla ◽  
Ashwini Nangia ◽  
Vladimir Chernyshev
Keyword(s):  
Hydrogen Bonds ◽  
Dissolution Rate ◽  
Aqueous Medium ◽  
Acid Amide ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Reference Drug ◽  
X Ray ◽  
Time Period ◽  
Solid Form

Acemetacin (ACM) is a non-steroidal anti-inflammatory drug (NSAID), which causes reduced gastric damage compared with indomethacin. However, acemetacin has a tendency to form a less soluble hydrate in the aqueous medium. We noted difficulties in the preparation of cocrystals and salts of acemetacin by mechanochemical methods, because this drug tends to form a hydrate during any kind of solution-based processing. With the objective to discover a solid form of acemetacin that is stable in the aqueous medium, binary adducts were prepared by the melt method to avoid hydration. The coformers/salt formers reported are pyridine carboxamides [nicotinamide (NAM), isonicotinamide (INA), and picolinamide (PAM)], caprolactam (CPR),p-aminobenzoic acid (PABA), and piperazine (PPZ). The structures of an ACM–INA cocrystal and a binary adduct ACM–PABA were solved using single-crystal X-ray diffraction. Other ACM cocrystals, ACM–PAM and ACM–CPR, and the piperazine salt ACM–PPZ were solved from high-resolution powder X-ray diffraction data. The ACM–INA cocrystal is sustained by the acid...pyridine heterosynthon and N—H...O catemer hydrogen bonds involving the amide group. The acid...amide heterosynthon is present in the ACM–PAM cocrystal, while ACM–CPR contains carboxamide dimers of caprolactam along with acid–carbonyl (ACM) hydrogen bonds. The cocrystals ACM–INA, ACM–PAM and ACM–CPR are three-dimensional isostructural. The carboxyl...carboxyl synthon in ACM–PABA posed difficulty in assigning the position of the H atom, which may indicate proton disorder. In terms of stability, the salts were found to be relatively stable in pH 7 buffer medium over 24 h, but the cocrystals dissociated to give ACM hydrate during the same time period. The ACM–PPZ salt and ACM–nicotinamide cocrystal dissolve five times faster than the stable hydrate form, whereas the ACM–PABA adduct has 2.5 times faster dissolution rate. The pharmaceutically acceptable piperazine salt of acemetacin exhibits superior stability, faster dissolution rate and is able to overcome the hydration tendency of the reference drug.

Characterization of New Nonstoichiometric Ferroelectric (Li0.95Cu0.15)Ta0.76Nb0.19O3 and Comparative Study With (Li0.95Cu0.15)Ta0.57Nb0.38O3 as Photocatalysts in Microbial Fuel Cells

2018 ◽  
Vol 16 (2) ◽  
Author(s):  
S. Louki ◽  
N. Touach ◽  
A. Benzaouak ◽  
V. M. Ortiz-Martínez ◽  
M. J. Salar-García ◽  
...  
Keyword(s):  
Power Density ◽  
Microbial Fuel Cells ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Ferroelectric Material ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Uv Visible

This work investigates the photocatalytic activity of new ferroelectric material with formula (Li0.95Cu0.15)Ta0.76Nb0.19O3 (LT76) in a single chamber microbial fuel cell (MFC) and compares its performance with the similar photocatalyst (Li0.95Cu0.15)Ta0.57Nb0.38O3 (LT57). The photocatalysts LT76 and LT57 were synthesized by ceramic route under the same conditions, with the same starting materials. The ratio Ta/Nb was fixed at 4.0 and 1.5 for LT76 and LT57, respectively. These phases were characterized by different techniques including X-ray diffraction (XRD), transmission electronic microscopy (TEM), particle size distribution (PSD), differential scanning calorimetry (DSC), and ultraviolet (UV)–visible (Vis). The new photocatalyst LT76 presents specific surface area of 0.791 m2/g and Curie temperature of 1197 °C. The photocatalytic efficiency of this material is assessed in terms of wastewater treatment and electricity generation by power density and removal rate of chemical oxygen demand (COD) in the presence of a light source. The values of maximum power density and COD removal were 19.77 mW/m3 and 93%, respectively, for LT76.

scholarly journals Stacking Control by Molecular Symmetry of Sterically Protected Phthalocyanines

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5552
Author(s):  
Ryota Kudo ◽  
Masahiro Sonobe ◽  
Yoshiaki Chino ◽  
Yu Kitazawa ◽  
Mutsumi Kimura
Keyword(s):  
Lamellar Structure ◽  
Synthesis And Characterization ◽  
Molecular Symmetry ◽  
X Ray Diffraction ◽  
Melting Points ◽  
Scanning Calorimetry ◽  
Structural Isomers ◽  
X Ray ◽  
Temperature Controlled

The synthesis and characterization of two phthalocyanine (Pc) structural isomers, 1 and 2, in which four 2,6-di(hexyloxy)phenyl units were attached directly to the 1,8,15,22- or 1,4,15,18-positions of the Pc rings, are described. Both Pcs 1 and 2 exhibited low melting points, i.e., 120 and 130 °C respectively, due to the reduction in intermolecular π-π interaction among the Pc rings caused by the steric hindrance of 2,6-dihexyloxybenzene units. The thermal behaviors were investigated with temperature-controlled polarizing optical microscopy, differential scanning calorimetry, powder X-ray diffraction, and absorption spectral analyses. Pc 1, having C4h molecular symmetry, organized into a lamellar structure containing lateral assemblies of Pc rings. In contrast, the other Pc 2 revealed the formation of metastable crystalline phases, including disordered stacks of Pcs due to rapid cooling from a melted liquid.

scholarly journals Characterization of the Interface Between the Bulk Glass Forming Alloy Zr41Ti14Cu12Ni10Be23 with Pure Metals and Ceramics

2000 ◽  
Vol 15 (7) ◽  
pp. 1617-1621 ◽  
Author(s):  
Jan Schroers ◽  
Konrad Samwer ◽  
Frigyes Szuecs ◽  
William L. Johnson
Keyword(s):  
Sessile Drop ◽  
Bulk Glass ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Glass Forming ◽  
Processing Times ◽  
Thermal Stability Of

The reaction of the bulk glass forming alloy Zr41Ti14Cu12Ni10Be23 (Vit 1) with W, Ta, Mo, AlN, Al2O3, Si, graphite, and amorphous carbon was investigated. Vit 1 samples were melted and subsequently solidified after different processing times on discs of the different materials. Sessile drop examinations of the macroscopic wetting of Vit 1 on the discs as a function of temperature were carried out in situ with a digital optical camera. The reactions at the interfaces between the Vit 1 sample and the different disc materials were investigated with an electron microprobe. The structure and thermal stability of the processed Vit 1 samples were examined by x-ray diffraction and differential scanning calorimetry. The results are discussed in terms of possible applications for composite materials.

scholarly journals COMPARISON STUDY OF GRINDING AND SLURRY METHOD ON PHYSICOCHEMICAL CHARACTERISTIC OF ACYCLOVIR – SUCCINIC ACID COCRYSTAL

2017 ◽  
Vol 10 (3) ◽  
pp. 153
Author(s):  
Fauzi Rahman ◽  
Agnes Nuniek Winantari ◽  
Dwi Setyawan ◽  
Siswandono .
Keyword(s):  
Fourier Transform ◽  
Ir Spectroscopy ◽  
Succinic Acid ◽  
Physicochemical Characteristic ◽  
Fourier Transform Infrared ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Slurry Method ◽  
Dissolution Efficiency

ABSTRACTObjective: This study aimed to compare the characteristics of acyclovir (ACV)-succinic acid (SA) cocrystal with grinding and slurry method.Methods: Cocrystals were prepared using grinding and slurry methods. Physicochemical characterizations were performed using powder X-raydiffraction (PXRD), differential scanning calorimetry, Fourier transform infrared (IR) spectroscopy, scanning electron microscope (SEM), anddissolution test.Results: The study revealed that cocrystal of ACV-SA showed a decrease in the melting temperature, i.e., 175.10°C, respectively, in comparison with themelting point of the constituent materials (ACV 253.53°C and SA 187.29°C). PXRD diffractogram showed that cocrystal with grinding method exhibitednew diffraction peaks at angle 2θ=8.92°, 16.24°, and 17.14°, while PXRD diffractogram of cocrystal with slurry method exhibit new diffraction peaksat angle 2θ=16.25°, and 19.63°. Characterization with IR spectroscopy showed the disappearance of transmission peaks at 3441cm disappearance ofC=O stretch at 1584cm and 1612cm. Dissolution efficiency of each treatment group calculated the efficiency of dissolution in 15th minutes, grindingmethod cocrystal with grinding time 15 minutes give the dissolution efficiency were 54.23%. Slurry method cocrystal with solvent concentration12 ml/g gives the high value of the dissolution efficiency is 74.36%. SEM micrographs showed that cocrystals prepared by solvent evaporation methodhave differences crystal form at magnification 5000× magnification compared to pure ACV and physical mixture.Conclusion: The study concluded that cocrystals of ACV-SA were successfully formed using grinding and slurry methods. The formed cocrystalsof ACV-SA exhibited different physicochemical characteristics as compared to the constituent materials. The formed cocrystals prepared by slurrymethod have a high intensity of diffraction peak on X-ray diffraction and highest dissolution efficiency at 15 minutes rather than grinding methodcocrystal.Keywords: Cocrystal, Acyclovir, Succinic acid, Grinding, Slurry, Powder X-ray diffraction, Fourier transform infrared, Dissolution rate. 

Synthesis and characterization of the new tin borate SnB8O11(OH)4

2018 ◽  
Vol 73 (5) ◽  
pp. 337-348 ◽  
Author(s):  
Sandra Schönegger ◽  
Klaus Wurst ◽  
Gunter Heymann ◽  
Andreas Schaur ◽  
Andreas Saxer ◽  
...  
Keyword(s):  
Hydrothermal Process ◽  
Building Blocks ◽  
Membered Ring ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermoanalytical Investigations ◽  
Hydrogen Bond Interactions ◽  
Simple Hydrothermal Process

AbstractA new tin(II) borate with the composition SnB8O11(OH)4 was synthesized by a simple hydrothermal process. It crystallizes in the centrosymmetric monoclinic space group P21/n (no. 14) with the lattice parameters a=790.1(1), b=1402.2(2), c=994.8(1) pm, and β=90.40(5)° (Z=4). The new compound SnB8O11(OH)4 is isotypic to PbB8O11(OH)4 and isostructural to BaB8O11(OH)4. The borate layers are built up from fundamental building blocks (FBBs) with the composition [B8O11(OH)4]2−. Four of these FBBs form a nine-membered ring wherein the Sn2+ cations are located. These boron-oxygen layers are further connected by O–H···O hydrogen bond interactions. The characterization of SnB8O11(OH)4 is based on single-crystal X-ray diffraction data, vibrational spectroscopy, DFT calculations, and thermoanalytical investigations including high temperature powder XRD.

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