scholarly journals Release of the Diclofenac Sodium by Nanofibers of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) Obtained from Electrospinning and Solution Blow Spinning

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Michelle Andrade Souza ◽  
Karine Yamamura Sakamoto ◽  
Luiz Henrique Capparelli Mattoso
Keyword(s):  
Diclofenac Sodium ◽  
X Ray Diffraction ◽  
Fiber Morphology ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
Polymer Nanofibers ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Solution Blow Spinning

Electrospun fibers are explored as a new system for controlled drug delivery. Novel techniques capable of obtaining polymer nanofibers have been reported in the literature. They include solution blow spinning (SBS), which is a technique to produce polymer nanofibers in the same range as electrospinning, using pressurized gas instead of high voltage. The present study investigates release characteristics of diclofenac sodium encapsulated at three concentrations (5, 10, and 20% w/v) in poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanofibers made by electrospinning and SBS and determines the drug’s effect on fiber morphology and structural properties. PHBV nanofibers were characterized using scanning electronic microscopy, differential scanning calorimetry, and X-ray diffraction, and the release profile was examined via UV-Vis spectrophotometry. Both electrospinning and SBS encapsulated diclofenac sodium in PHBV membranes efficiently and effectively. The profile of thein vitrorelease of diclofenac sodium was dependent on drug concentration and temperature. The drug reduced crystallinity and increased flexibility.

scholarly journals The Dehydrogenation Mechanism and Reversibility of LiBH4 Doped by Active Al Derived from AlH3

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 559 ◽  
Author(s):  
Qing He ◽  
Dongdong Zhu ◽  
Xiaocheng Wu ◽  
Duo Dong ◽  
Xiaoying Jiang ◽  
...  
Keyword(s):  
Reaction Products ◽  
X Ray Diffraction ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
Scanning Calorimetry ◽  
Mass Spectral Analysis ◽  
X Ray ◽  
Mass Spectral ◽  
Al Composite ◽  
Dehydrogenation Mechanism

A detailed analysis of the dehydrogenation mechanism and reversibility of LiBH4 doped by as-derived Al (denoted Al*) from AlH3 was performed by thermogravimetry (TG), differential scanning calorimetry (DSC), mass spectral analysis (MS), powder X-ray diffraction (XRD), scanning electronic microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). The results show that the dehydrogenation of LiBH4/Al* is a five-step reaction: (1) LiBH4 + Al → LiH + AlB2 + “Li-Al-B-H” + B2H6 + H2; (2) the decomposition of “Li-Al-B-H” compounds liberating H2; (3) 2LiBH4 + Al → 2LiH + AlB2 + 3H2; (4) LiBH4 → LiH + B + 3/2H2; and (5) LiH + Al → LiAl + 1/2H2. Furthermore, the reversibility of the LiBH4/Al* composite is based on the following reaction: LiH + LiAl + AlB2 + 7/2H2 ↔ 2LiBH4 + 2Al. The extent of the dehydrogenation reaction between LiBH4 and Al* greatly depends on the precipitation and growth of reaction products (LiH, AlB2, and LiAl) on the surface of Al*. A passivation shell formed by these products on the Al* is the kinetic barrier to the dehydrogenation of the LiBH4/Al* composite.

scholarly journals The Dehydrogenation Mechanism and Reversibility of LiBH4 Doped by Active Al* Derived from AlH3

2019 ◽  
Author(s):  
Qing He ◽  
Dongdong Zhu ◽  
Xiaocheng Wu ◽  
Duo Dong ◽  
Xiaoying Jiang ◽  
...  
Keyword(s):  
Reaction Products ◽  
X Ray Diffraction ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
Scanning Calorimetry ◽  
Mass Spectral Analysis ◽  
X Ray ◽  
Mass Spectral ◽  
Al Composite ◽  
Dehydrogenation Mechanism

A detailed analysis of the dehydrogenation mechanism and reversibility of LiBH4 doped by active Al* derived from AlH3 was performed by thermogravimetry (TG), differential scanning calorimetry (DSC), mass spectral analysis (MS), powder X-ray diffraction (XRD), scanning electronic microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The results show that the dehydrogenation of LiBH4/Al* is a five-step reaction: (1) LiBH4 + Al → LiH + AlB2 + “Li-Al-B-H” + B2H6 + H2; (2) the decomposition of "Li-Al-B-H" compounds liberating H2; (3) 2LiBH4 + Al → 2LiH + AlB2 + 3H2; (4) LiBH4 → LiH + B + 3/2H2; (5) LiH + Al → LiAl + 1/2H2. And the reversibility of LiBH4/Al* composite is based on equation as follows: LiH + LiAl + AlB2 + 7/2H2 ↔ 2LiBH4 + 2Al. The extent of dehydrogenation reaction between LiBH4 and Al* greatly depends on the precipitation and growth of reaction products (LiH, AlB2 and LiAl, etc.) on the surface of Al*. A passivation shell of Al* formed by these products is the kinetic barrier to the dehydrogenation of LiBH4/Al* composite.

scholarly journals Development of an Oxcarbazepine Solid Dispersion Using Skimmed Milk to Improve the Solubility and Dissolution Profile

2019 ◽  
Vol 11 (05) ◽  
Author(s):  
M. Shah ◽  
D. Patel
Keyword(s):  
Electron Microscopy ◽  
Solid Dispersion ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Infra Red ◽  
Crystalline Nature ◽  
Skimmed Milk ◽  
Scanning Electron

Oxcarbazepine has low solubility and low oral bioavailability, so it’s a challenge to formulate suitable dosage form. In this present investigation, to improve the dissolution rate and solubility, skimmed milk is used as a carrier. Physical mixers were prepared using various drugs to carrier ratio and spray drying technology was used to develop solid dispersion with the carrier. Various techniques were used to characterize the solid dispersion immediately after they were made which includes differential scanning calorimetry, scanning electron microscopy, fourier transform infra- red spectroscopy, X-ray diffraction and in-vitro dissolution profiles. The differential scanning calorimetry thermograms of raw drug indicated of its anhydrous crystalline nature. In thermograms of solid dispersion, the characteristic peak was absent suggesting the change from crystalline nature to amorphous form. X-ray diffraction confirmed those results. X-ray diffraction results of raw drug showed highly intense peak characteristic of its crystalline nature where solid dispersion showed less intense, more diffused peak indicating the change in crystalline form. Fourier transforms infra-red spectroscopy studies showed there was no interaction between drug and carrier. Scanning electron microscopy support the amorphous nature of mixer. The whole formulation showed distinct enhancement in the drug release behavior and solubility. The optimum oxcarbazepine to skimmed milk ratio 1:3 enhances the in-vitro drug release by 3.5 fold and also show distinct increase in solubility. It was concluded that for improvement of solubility of poorly water soluble oxcarbazepine, skimmed milk powder as a carrier can be utilize very well.

scholarly journals Development and In-Vitro Evaluation of pH Responsive Polymeric Nano Hydrogel Carrier System for Gastro-Protective Delivery of Naproxen Sodium

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Rai Muhammad Sarfraz ◽  
Muhammad Rouf Akram ◽  
Muhammad Rizwan Ali ◽  
Asif Mahmood ◽  
Muhammad Usman Khan ◽  
...  
Keyword(s):  
Drug Release ◽  
Naproxen Sodium ◽  
Research Work ◽  
Entrapment Efficiency ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Swelling Behaviour ◽  
X Ray

Current research work was carried out for gastro-protective delivery of naproxen sodium. Polyethylene glycol-g-poly (methacrylic acid) nanogels was developed through free radical polymerization technique. Formulation was characterized for swelling behaviour, entrapment efficiency, Fourier transform infrared (FTIR) spectroscopy, Differential scanning calorimetry (DSC), and Thermal Gravimetric Analysis (TGA), Powder X-ray diffraction (PXRD), Zeta size distribution, and Zeta potential measurements, and in-vitro drug release. pH dependent swelling was observed with maximum drug release at higher pH. PXRD studies confirmed the conversion of loaded drug from crystalline to amorphous form while Zeta size measurement showed size reduction. On the basis of these results it was concluded that prepared nanogels proved an effective tool for gastro-protective delivery of naproxen sodium.

Characterization of Shivirtui Zeolite Modified with Aluminum Oxyhydroxide Nanofibers

2019 ◽  
Vol 942 ◽  
pp. 40-49
Author(s):  
Yulia Murashkina ◽  
Olga B. Nazarenko
Keyword(s):  
Chemical Properties ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
X Ray ◽  
Physical And Chemical ◽  
And Chemical Properties ◽  
Aluminum Oxyhydroxide

Natural zeolite of Shivirtui deposit (Russia) was modified with nanofibers of aluminum oxyhydroxide AlOOH. Aluminum oxyhydroxide nanofibers were produced at the heating and oxidation of aluminum powder with water. The properties of modified zeolite were investigated by means of X-ray diffraction, transmission electronic microscopy, scanning electronic microscopy, low-temperature nitrogen adsorption, thermal analysis, and Fourier transform infrared spectroscopy. It was found that water content in the modified sample of zeolite was about 15 %. Based on the study of the physical and chemical properties, shivirtui zeolite modified with nanofibers of aluminum oxyhydroxide can be proposed for use as a flame-retardant additive to polymers.

The preparation, characterization, structure and dissolution analysis of apremilast solvatomorphs

2017 ◽  
Vol 73 (4) ◽  
pp. 305-313 ◽  
Author(s):  
Yun-Deng Wu ◽  
Xiao-Lei Zhang ◽  
Xiao-Hong Liu ◽  
Jian Xu ◽  
Mei Zhang ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Hydrogen Bonding ◽  
Psoriatic Arthritis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Dissolution Rates ◽  
X Ray ◽  
Similarity Factor ◽  
Hydrogen Bonding Interactions

Apremilast (AP) {systematic name: (S)-2-[1-(3-ethoxy-4-methoxyphenyl)-2-(methylsulfonyl)ethyl]-4-acetamidoisoindoline-1,3-dione} is an inhibitor of phosphodieasterase-4 (PDE4) and is indicated for the treatment of adult patients with active psoriatic arthritis. The ability of AP to form solvates has been investigated and three solvatomorphs of AP, namely, the AP ethyl acetate hemisolvate, C22H24N2O7S·0.5C4H8O2, the AP toluene hemisolvate, C22H24N2O7S·0.5C7H8, and the AP dichloromethane monosolvate, C22H24N2O7S·CH2Cl2, were obtained. The three AP solvatomorphs were characterized by X-ray powder diffraction, thermogravimetric analysis and differential scanning calorimetry. Single-crystal X-ray diffraction was used to analyze the structures, crystal symmetry, packing modes, stoichiometry and hydrogen-bonding interactions of the solvatomorphs. In addition, dissolution analyses were performed to study the dissolution rates of different AP solvatomorph tablets in vitro and to make comparisons with commercial apremilast tablets (produced by Celgene); all three solvatomorphs showed similar dissolution rates and similar values of the similarity factor f2 in a comparison of their dissolution profiles.

Study of the Synthesis of Mullite From Kaolin-α-Al2O3 and Kaolin-Al(NO3)3

2012 ◽  
Vol 1481 ◽  
pp. 11-17
Author(s):  
E. M. Lozada ◽  
O. Alanís ◽  
F. Legorreta ◽  
L. E. Hernández
Keyword(s):  
Combustion Method ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
X Ray Diffraction ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
X Ray ◽  
Crystallographic Study ◽  
Incomplete Reaction ◽  
Α Al2o3

ABSTRACTThe synthesis of mullite from kaolin clay and two precursors of aluminum: α-Al2O3 and Al(NO3)3 was investigated. In order to study the temperature effect, the system kaolin-α-Al2O3 was calcined in air in a range of 1200 to 1500°C, for 2 h. For the system kaolin-Al(NO3)3, the combustion method was employed, using urea as fuel, and calcined in air at 1500°C for 2 h. The products were characterized by X-ray diffraction, scanning electronic microscopy (SEM), energy dispersive spectroscopy and particle size analysis in order to analyze and compare their morphology and structure. The crystallographic study revealed an incomplete reaction between the kaolin and the α-Al2O3. Nevertheless, in the system kaolin-Al(NO3)3, it was obtained mullite with high purity and trace amounts of cristobalite.

Fabrication and Magnetic Properties of Fe3O4 Nanobranches via a Simple Solvothermal Method

2011 ◽  
Vol 335-336 ◽  
pp. 934-939
Author(s):  
Z. F. Zi ◽  
Y. N. Liu ◽  
Q.C. Liu ◽  
Jian Ming Dai ◽  
Yu Ping Sun
Keyword(s):  
Magnetic Properties ◽  
Single Phase ◽  
Solvothermal Method ◽  
X Ray Diffraction ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
X Ray ◽  
Water Solvent ◽  
Phase Spinel ◽  
Antisite Defects

Magnetite (Fe3O4) nanobranches were synthesized using an improved solvothermal technique in mixed ethanol and water solvent. Structural and magnetic properties were systematically investigated. X-ray diffraction results showed that the sample was single-phase spinel structure. The results of scanning electronic microscopy exhibited that the grains were regular like-branch with sizes from 3 to 6 μm in length and in diameter between 50 and 200 nm. The composition determined by energy dispersive spectroscopy was very close to the stoichiometry of Fe3O4. The saturation magnetizations (Ms) at 10 and 300 K of the synthesized Fe3O4nanobranches were much lower than the theoretical values. On one hand, it could be explained by obstructive magnetizing along their non-easy magnetic axes by the shape anisotropy of Fe3O4nanobranches, on the other hand, lesserMscan also be understood by the existence of antisite defects.

scholarly journals Hydrophilic Sugars for Enhancing Dissolution Rate of Cilostazol: Effect of Wet Co-Processing

2020 ◽  
Vol 27 (1) ◽  
pp. 111-120
Author(s):  
Alaa Yosf Bazeed ◽  
Ahmed Nouh ◽  
Ebtessam Ahmed Essa ◽  
Gamal El Maghraby
Keyword(s):  
Aqueous Solubility ◽  
Submicron Particles ◽  
Drug Dissolution ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Swallowing Difficulties ◽  
Fast Disintegrating Tablets

Background: Cilostazol is an anti-platelets drug with considerable antithrombotic effects in vivo. Therefore, it is widely used by elderly patients. However, it suffers from poor bioavailability due to its low aqueous solubility. The objective of this work was to enhance the dissolution of cilostazol with the aim of formulating fast dissolving tablets for geriatrics and those of swallowing difficulties. Methods: Ethanol-assisted co-grinding of cilostazol with sugar-based excipients was adopted. Sucralose and mannitol were used for this purpose as hydrophilic excipient as well as taste improving agents. The obtained products were investigated regarding differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction, scanning electron microscope (SEM) and in vitro drug dissolution. Fast disintegrating tablets were prepared and evaluated. Results: Thermal behavior of the developed products reflected reduced crystallinity, it also suggested possible existence of new crystalline species with sucralose. Eutexia was also suggested for mannitol mixtures, that was supported by X-ray diffraction data. SEM indicated size reduction with the deposition of the drug as submicron particles over the excipient surface. Co-processing markedly improved cilostazol dissolution compared to unprocessed drug. The optimized formulations were successively formulated into fast disintegrating tablets. Conclusion: This investigation introduced the wet grinding strategy with sugar excipients as a platform for the formulation of easy to use tablets with optimum drug release.

scholarly journals Structure and composition of soils

2010 ◽  
Vol 4 (4) ◽  
pp. 259-263 ◽  
Author(s):  
Snezana Nenadovic ◽  
Milos Nenadovic ◽  
Ljiljana Kljajevic ◽  
Vladimir Pavlovic ◽  
Aleksandar Djordjevic ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Porous Structure ◽  
X Ray Diffraction ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
Characterization Methods ◽  
Soil Particles ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force

This paper presents a study of soils structure and composition using up to date technique, such as scanning electronic microscopy, atomic force microscopy, X-ray diffraction, X-ray fluorescence, as well as some other characterization methods. It was shown that soil particles have porous structure and dimensions in the range from several millimeters to several hundreds of nanometers and consist of different minerals such as kaolin, quartz and feldspate.

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