scholarly journals Computer-Aided Design of Cefuroxime Axetil/Cyclodextrin System with Enhanced Solubility and Antimicrobial Activity

Biomolecules ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 24 ◽  
Author(s):  
Mikołaj Mizera ◽  
Daria Szymanowska ◽  
Anna Stasiłowicz ◽  
Dominika Siąkowska ◽  
Kornelia Lewandowska ◽  
...  
Keyword(s):  
Theoretical Model ◽  
Computer Aided Design ◽  
Active Pharmaceutical Ingredient ◽  
Cefuroxime Axetil ◽  
Antimicrobial Efficacy ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Enhanced Solubility ◽  
Ft Ir ◽  
Aided Design

This study aimed to investigate changes in the solubility and antimicrobial efficacy of cefuroxime axetil (CA) when incorporated into cyclodextrin (CD). While choosing the CD, the validated in silico model was used. A theoretical model based on docking and molecular mechanics/generalized born surface area was validated using a curated dataset of API (active pharmaceutical ingredient)–CD stability constants. The library of commonly used cyclodextrins was virtually screened, indicating CA –hydroxypropyl-βCD (HPβCD) as the most thermodynamically favored system. Solid-state CA–HPβCD system was prepared and characterized by differential scanning calorimetry (DSC), Fourier-transform infrared (FT-IR), and X-ray diffraction (XRPD) methods. The dissolution profiles of the CA and its cyclodextrin system were evaluated. Microbiological activity of the CA–HPβCD inclusion system was studied based on changes in minimal inhibitory concentration (MIC) values and related to ones of the pure CA. The theoretical model was successfully validated, obtaining an average correlation with experimental data R = 0.7. The dissolution study showed significantly improved dissolution profiles of CA–HPβCD compared to CA. HPβCD increases the antimicrobial efficacy of CA up to 4-fold compared to pure CA.

Liquid crystalline polyureas with oligo(ethylene glycol) sequences

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Shahram Mehdipour-Ataei ◽  
Leila Akbarian-Feizi
Keyword(s):  
Liquid Crystalline ◽  
Spectroscopic Method ◽  
Polymerization Reaction ◽  
X Ray Diffraction ◽  
Subsequent Reaction ◽  
Scanning Calorimetry ◽  
Polar Solvents ◽  
X Ray ◽  
H Nmr ◽  
Ft Ir

AbstractA diamine monomer containing ester, amide and ether functional groups was prepared and its polymerization reaction with different diisocyanates to give main chain poly(ester amide ether urea)s was investigated. The monomer was synthesized via reaction of terephthaloyl chloride with 4-hydroxybenzoic acid and subsequent reaction of the resulted diacid with 1,8-diamino-3,6-dioxaoctane. The polymers were characterized by FT-IR and 1H-NMR spectroscopic method and elemental analysis. The resulting polymers exhibited excellent solubility in polar solvents. Crystallinity of the resulted polymers was evaluated by wide-angle X-ray diffraction (WXRD) method, and they exhibited semi-crystalline patterns. The glass transition temperatures (Tg) of the polymers determined by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) were in the range of 88-112 °C. The temperatures for 10% weight loss (T10) from their thermogravimetric analysis (TGA) curves were found to be in the range of 297-312 °C in air. Also the prepared polyureas showed liquid crystalline character.

Synthesis and Properties of Thermotropic Liquid Crystalline Polyesters with Flexible Polymethylene Spacer

2010 ◽  
Vol 428-429 ◽  
pp. 126-131
Author(s):  
Wei Zhong Lu ◽  
Chun Wei ◽  
Qui Shan Gao
Keyword(s):  
Optical Microscopy ◽  
Liquid Crystalline ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Structure Morphology ◽  
Temperature Ranges ◽  
Ft Ir ◽  
Diffraction Peaks ◽  
Ubbelohde Viscometer

Polymethylene bis(p-hydroxybenzoates) were prepared from methyl p-hydroxybenzoate and different diols by melted transesterification reaction. Three liquid crystalline polyesters were synthesized from terephthaloyl dichloride and polymethylene bis(p-hydroxybenzoates). Its structure, morphology and properties were characterized by Ubbelohde viscometer, Fourier transform infrared spectroscopy (FT-IR), Differential scanning calorimetry (DSC), polarized optical microscopy (POM) with a hot stage, and wide-angle X-ray diffraction (WAXD). Results indicated that the intrinsic viscosities were between 0.088 and 0.210 dL/g. Optical microscopy showed that the TLCP has a highly threaded liquid crystalline texture and a high birefringent schlieren texture character of nematic phase and has wider mesophase temperature ranges for all polyesters. DSC analysis were found that the melting point (Tm), isotropic temperature (Ti) of TLCPs decreased and the temperature range of the liquid crystalline phase became wider with increased number of methylene spacers in the polyester. The WAXD results showed that TLCPs owned two strong diffraction peaks at 2θ near 19° and 23°.

Compatibility between Magnesium Stearate and Pharmaceutical Acidic Active Compounds/Excipients with DSC

2020 ◽  
Vol 856 ◽  
pp. 190-197
Author(s):  
Pornsit Chaiya ◽  
Thawatchai Phaechamud
Keyword(s):  
Differential Scanning Calorimetry ◽  
Magnesium Stearate ◽  
X Ray Diffraction ◽  
Salt Form ◽  
Scanning Calorimetry ◽  
Powder Mixtures ◽  
X Ray ◽  
Pharmaceutical Excipients ◽  
Drug Compounds ◽  
Ft Ir

Compatibility investigation was performed between magnesium stearate and acidic drug compounds (ibuprofen, indomethacin and valproic acid) and acidic pharmaceutical excipients (lactic acid and citric acid) using differential scanning calorimetry (DSC). DSC study indicated the possible incompatibility for the mixture between magnesium stearate and any compounds. Alteration in DSC thermogram was found in all mixtures. The eutectic phenomenon was found in the powder mixture of magnesium stearate and ibuprofen. In addition, the presence of melting endothermic peak of stearic acid in other powder mixtures except the mixture of magnesium stearate and indomethacin indicating breakage of salt form of magnesium stearate. This alteration could relate to the influence on physicochemical properties of drug compounds and pharmaceutical excipients which powder x-ray diffraction (PXRD) and Fourier Transform Infrared Spectroscopy (FT-IR) should be further analyzed to confirm the interactions between compounds.

Stress-Induced Crystal-to-Crystal Transformations in High-Density Polyethylene-Layered Silicate Nanocomposites: A Spectroscopic Study

2005 ◽  
Vol 59 (9) ◽  
pp. 1148-1154 ◽  
Author(s):  
Spiros Tzavalas ◽  
Vasilis G. Gregoriou
Keyword(s):  
High Density Polyethylene ◽  
Mechanical Strain ◽  
Layered Silicate ◽  
High Density ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Polyethylene Matrix ◽  
Dsc Measurements ◽  
Infrared Measurements ◽  
Ft Ir

High-density polyethylene (HDPE)–clay nanocomposites have been prepared using the melt intercalation technique. Organically modified montmorillonite at various loadings (0.5–7%) was used as a nanoadditive. Fourier transform infrared spectroscopy (FT-IR) was utilized for the first time to monitor the stress-induced crystal-to-crystal transformations of the polyethylene matrix with respect to the clay loading as well as to the degree of mechanical strain. In addition, polarized infrared measurements revealed information on both the orientation and the stress-induced distortion of the crystals. It was concluded that the crystal-to-crystal transformations are hindered by the presence of the clay, which also prevented the crystals from orienting even at low clay loadings (1%). Finally, X-ray diffraction (XRD) and differential scanning calorimetry (DSC) measurements confirmed the presence of the stress-induced crystalline structures in agreement with the infrared measurements.

scholarly journals Preparation and Properties of Ginger Essential Oil β-Cyclodextrin/Chitosan Inclusion Complexes

Coatings ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 305 ◽  
Author(s):  
Yan Zhang ◽  
Hui Zhang ◽  
Fang Wang ◽  
Li-Xia Wang
Keyword(s):  
Particle Size ◽  
Essential Oil ◽  
Spray Drying ◽  
Small Particle Size ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ft Ir ◽  
Thermal Stability Of ◽  
Scanning Electron

The ginger essential oil/β-cyclodextrin (GEO/β-CD) composite, ginger essential oil/β-cyclodextrin/chitosan (GEO/β-CD/CTS) particles and ginger essential oil/β-cyclodextrin/chitosan (GEO/β-CD/CTS) microsphere were prepared with the methods of inclusion, ionic gelation and spray drying. Their properties were studied by using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermo-gravimetry analysis (TGA), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The results showed that the particle size of GEO/β-CD composite was smaller than that of β-CD and GEO/β-CD/CTS particles were loose and porous, while the microsphere obtained by spray drying had certain cohesiveness and small particle size. Besides, results also indicated that β-CD/CTS could modify properties and improve the thermal stability of GEO, which would improve its application value in food and medical industries.

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.

Powder Bed Fusion of Biomedical Co-Cr-Mo and Ti-6Al-4V Alloys: Microstructure and Mechanical Properties

2019 ◽  
Vol 1151 ◽  
pp. 3-7 ◽  
Author(s):  
Eleonora Santecchia ◽  
Paolo Mengucci ◽  
Andrea Gatto ◽  
Elena Bassoli ◽  
Lucia Denti ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Tensile Tests ◽  
Layer By Layer ◽  
Powder Bed Fusion ◽  
X Ray Diffraction ◽  
Powder Bed ◽  
Mechanical Parts ◽  
Aided Design ◽  
Microscopy Techniques ◽  
High Degree

Powder bed fusion (PBF) is an additive manufacturing technique, which allows to build complex functional mechanical parts layer-by-layer, starting from a computer-aided design (CAD) model. PBF is particularly attractive for biomedical applications, where a high degree of individualization is required. In this work, the microstructure of two biomedical alloys, namely Co-Cr-Mo and Ti-6Al-4V, were studied by X-ray diffraction and electron microscopy techniques. Hardness and tensile tests were performed on the sintered parts.

scholarly journals Compression-Induced Phase Transitions of Bicalutamide

Pharmaceutics ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 438 ◽  
Author(s):  
Joanna Szafraniec-Szczęsny ◽  
Agata Antosik-Rogóż ◽  
Justyna Knapik-Kowalczuk ◽  
Mateusz Kurek ◽  
Ewa Szefer ◽  
...  
Keyword(s):  
Solid Dispersions ◽  
Amorphous Solid ◽  
Active Pharmaceutical Ingredient ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Amorphous Solid Dispersions ◽  
X Ray ◽  
High Propensity ◽  
Poorly Soluble ◽  
Amorphous Drug

The formation of solid dispersions with the amorphous drug dispersed in the polymeric matrix improves the dissolution characteristics of poorly soluble drugs. Although they provide an improved absorption after oral administration, the recrystallization, which can occur upon absorption of moisture or during solidification and other formulation stages, serves as a major challenge. This work aims at understanding the amorphization-recrystallization changes of bicalutamide. Amorphous solid dispersions with poly(vinylpyrrolidone-co-vinyl acetate) (PVP/VA) were obtained by either ball milling or spray drying. The applied processes led to drug amorphization as confirmed using X-ray diffraction and differential scanning calorimetry. Due to a high propensity towards mechanical activation, the changes of the crystal structure of physical blends of active pharmaceutical ingredient (API) and polymer upon pressure were also examined. The compression led to drug amorphization or transition from form I to form II polymorph, depending on the composition and applied force. The formation of hydrogen bonds confirmed using infrared spectroscopy and high miscibility of drug and polymer determined using non-isothermal dielectric measurements contributed to the high stability of amorphous solid dispersions. They exhibited improved wettability and dissolution enhanced by 2.5- to 11-fold in comparison with the crystalline drug. The drug remained amorphous upon compression when the content of PVP/VA in solid dispersions exceeded 20% or 33%, in the case of spray-dried and milled systems, respectively.

scholarly journals Study of the Influence of the Almond Shell Variety on the Mechanical Properties of Starch-Based Polymer Biocomposites

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2049 ◽  
Author(s):  
Ana Ibáñez García ◽  
Asunción Martínez García ◽  
Santiago Ferrándiz Bou
Keyword(s):  
Charpy Impact ◽  
X Ray Diffraction ◽  
Almond Shell ◽  
Scanning Calorimetry ◽  
Commercial Mixture ◽  
Hardness Tests ◽  
Twin Screw ◽  
Ft Ir ◽  
Mechanical Tensile ◽  
The Individual

This article is focused on the development of a series of biodegradable and eco-friendly biocomposites based on starch polymer (Mater-Bi DI01A) filled with 30 wt% almond shell (AS) of different varieties (Desmayo Rojo, Largueta, Marcona, Mollar, and a commercial mixture of varieties) to study the influence of almond variety in the properties of injected biodegradable parts. The different AS varieties are analysed by means of Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), Scanning Electron Microscopy (SEM), and X-ray Diffraction (XRD). The biocomposites are prepared in a twin-screw extruder and characterized in terms of their mechanical (tensile, flexural, Charpy impact, and hardness tests) and thermal properties (differential scanning calorimetry (DSC) and TGA). Despite observing differences in the chemical composition of the individual varieties with respect to the commercial mixture, the results obtained from the mechanical characterisation of the biocomposites do not present significant differences between the diverse varieties used. From these results, it was concluded that the most recommended option is to work with the commercial mixture of almond shell varieties, as it is easier and cheaper to acquire.

Structures and physicochemical properties of vortioxetine salts

2016 ◽  
Vol 72 (5) ◽  
pp. 723-732 ◽  
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.

Sign in / Sign up

Export Citation Format

Share Document