scholarly journals Synthesis of New Amino—β-Cyclodextrin Polymer, Cross-Linked with Pyromellitic Dianhydride and Their Use for the Synthesis of Polymeric Cyclodextrin Based Nanoparticles

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1332
Author(s):  
Kinga Kozieł ◽  
Jakub Łagiewka ◽  
Beata Girek ◽  
Agnieszka Folentarska ◽  
Tomasz Girek ◽  
...  
Keyword(s):  
Water Soluble ◽  
Cyclodextrin Derivatives ◽  
Amino Groups ◽  
Scanning Calorimetry ◽  
Dsc Studies ◽  
Cyclodextrin Polymer ◽  
Amino Derivatives ◽  
Pyromellitic Anhydride ◽  
First Time ◽  
Scanning Electron

New water soluble amino β-cyclodextrin-based polymer was synthesized by reaction between amino cyclodextrin derivatives and pyromellitic anhydride. This experiment presents amino derivatives, which were synthesized by attaching amino groups to β-cyclodextrins (β-CDs) used mono-6-azido-6-deoxy-β-cyclodextrin (β-CD-N3) and triphenylphosphine (Ph3P) in anhydrous N,N-dimethylformamide (DMF). An amino blocking reaction was conducted. The obtained polymer was purified by ultrafiltration. In addition, an attempt was made to create nanospheres by encapsulating the polymer with chitosan (CT) in an acidic condition. For the first time, nanospheres were obtained in the reaction between an amino β-cyclodextrin polymer and chitosan. Scanning electron microscopy (SEM). 1H NMR and ESI-MS methods for confirmation of reaction product and for structural characterization were employed. The differential scanning calorimetry (DSC) studies of polymers were also carried out.

scholarly journals Ag(I) Catalyzed Grafting of Acrylonitrile onto Gum Arabic by Ce(IV) in Medium: A Kinetic Study

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Geeta Thota ◽  
P. Srinivas
Keyword(s):  
Electron Microscopy ◽  
Gum Arabic ◽  
Probable Mechanism ◽  
Water Soluble ◽  
Graft Polymer ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Water Soluble Polymer ◽  
X Ray ◽  
Scanning Electron

Grafting of Acrylonitrile (AN) onto water-soluble polymer Gum arabic (GA) was carried out using ceric ammonium sulfate [Ce(IV)] as initiator in the presence and absence of Ag(I) in H2SO4 medium at 313 K. The rate of oxidation (), rate of grafting (), and grafting efficiency (GE) were determined for catalyzed and uncatalyzed grafting and suitable mechanism was proposed to explain the observed results. No homopolymerization in the absence of GA indicates that the polymer obtained is purely a graft copolymer. A probable mechanism involving the formation of Ag(I)-GA adduct followed by its oxidation with Ce(IV) to give Ag(II)-GA adduct, and its decomposition to give initiating radicals is proposed to explain the observed results. The graft polymer was characterized using Fourier-transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), X-ray diffraction, and scanning electron microscopy (SEM) considering GA as reference.

Formulation and Evaluation of Atorvastatin Solid Dispersions using Entada scandens seed starch as Superdisintegrant

2021 ◽  
pp. 5141-5149
Author(s):  
Sandeep Doppalapudi ◽  
Vidyadhara Suryadevara ◽  
Sailaja Yallam ◽  
Sowjanya Lakshmi Battula ◽  
Vanya Nayudu
Keyword(s):  
Solid Dispersions ◽  
Pharmaceutical Research ◽  
Surface Characteristics ◽  
Water Soluble ◽  
Physical Parameters ◽  
Poorly Soluble Drugs ◽  
Scanning Calorimetry ◽  
Dsc Studies ◽  
Poorly Soluble ◽  
Evaporation Technique

The present work mainly focuses on solubility enhancement of poorly soluble drugs using superdisintegrants. One of such poorly soluble drugs is Atorvastatin, which belongs to the category of statins. Atorvastatin belongs to BCS class – II, which is poorly water soluble and highly permeable. Natural sources are now-a-days playing a key role in pharmaceutical research. They have several pharmaceutical applications. Starches obtained from plants are pharmaceutically useful as binders, diluents, disintegrants and lubricants. Various physical parameters were evaluated. Solid dispersions were prepared using solvent evaporation technique. Where as in solid dispersions, formulations F2 and F5 showed better dissolution rate compared with other formulations. Fourier Transform Infra red spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC) studies for optimized formulations revealed that there were no major interactions between the drug and excipients. X-Ray Diffraction (XRD) studies revealed the crystalline and amorphous nature of formulations. Scanning Electron Microscopy (SEM) revealed the surface characteristics. Thus from the present study, it was concluded that Entada scandens seed starch posses superdisintegrant property.

scholarly journals Preparation of Miscible PVA/PEG Blends and Effect of Graphene Concentration on Thermal, Crystallization, Morphological, and Mechanical Properties of PVA/PEG (10 wt%) Blend

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Fahad H. Falqi ◽  
Osamah A. Bin-Dahman ◽  
M. Hussain ◽  
Mamdouh A. Al-Harthi
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Testing Machine ◽  
Water Soluble ◽  
Poly Vinyl Alcohol ◽  
Scanning Calorimetry ◽  
Tensile Testing Machine ◽  
Elongation At Break ◽  
Casting Technique ◽  
Dsc Studies

Water-soluble polymers such as poly(vinyl alcohol) (PVA) and poly(ethylene glycol) (PEG) and their nanocomposites with graphene were prepared by using a solution mixing and casting technique. The effect of different PEG loadings was investigated to determine the optimum blend ratio. The films were characterized using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and thermogravimetric analyzer (TGA) methods. Also, the mechanical properties including tensile strength and elongation at break were measured using a universal tensile testing machine. FTIR results confirmed the formation of the H-bond between PEG and PVA. DSC studies revealed that PEG has a significant plasticization effect on PVA as seen by the drop in the glass transition temperature (Tg). The blend with 10 wt% PEG loading was found to be the optimum blend because of good compatibility as shown by FTIR and SEM results and improved thermal properties. PVA/PEG (10%) nanocomposites were prepared using graphene as a nanofiller. It was found that the elongation at break increased by 62% from 147% for the PVA/PEG (10%) blend to 209% for the nanocomposite with graphene loading of 0.2 wt%. The experimental values of tensile strength were compared using the predictive model of Nicolais and Narkis.

scholarly journals Effect of processing temperatures on the thermal and mechanical properties of leather waste-ABS composites

2021 ◽  
Vol 30 ◽  
pp. 263498332110600
Author(s):  
Macaulay M. Owen ◽  
Emmanuel O. Achukwu ◽  
Innocent O. Arukalam ◽  
Mustakim Muhammad ◽  
Ahmad Z. Romli
Keyword(s):  
Mechanical Properties ◽  
Acrylonitrile Butadiene Styrene ◽  
Processing Temperature ◽  
Thermal And Mechanical Properties ◽  
Scanning Calorimetry ◽  
Dsc Studies ◽  
Melting Temperatures ◽  
Leather Wastes ◽  
Scanning Electron ◽  
Butadiene Styrene

The effect of varying processing temperatures (200, 220 and 240°C) on the thermal and mechanical properties of uncoated and epoxy-coated chrome-tanned leather wastes-ABS composites has been studied. The results obtained showed that the mechanical properties of the composites decreased as the processing temperature increased. Epoxy-coated leather wastes fibre-ABS (CLWABS) composite yielded better mechanical properties compared to the uncoated leather wastes-ABS composite (LWABS). These results were obtained at an optimized processing temperature of 200°C. Furthermore, the results were confirmed by the field emission scanning electron microscopy (FESEM) studies. The differential scanning calorimetry (DSC) studies revealed that the epoxy-coated leather wastes fibres (CLW) showed higher onset and melting temperatures of 131.8 and 179.35°C than the uncoated leather wastes fibres (LW) with glass transition (Tg) and melting (Tm) temperatures of 128.2 and 169.4°C, respectively. When the LW and CLW fibres were mixed with Acrylonitrile butadiene styrene (ABS), the Tg and Tm of CLWABS composite were found to be 94.9 and 269.8°C, respectively, higher than the LWABS composite with Tg and Tm of 89.1 and 261.6°C, respectively. Thus, this study has demonstrated that utilization of epoxy-coated chrome-tanned leather wastes fibres as fillers in the design of ABS-based composites will help a great deal in addressing the problem of solid waste pollutants in our environment.

scholarly journals Comparative study of the effect of TiO2 and ZnO on the crystallization of PHB

2017 ◽  
Vol 22 (4) ◽  
Author(s):  
Nichollas Guimarães Jaques ◽  
Ingridy Dayane dos Santos Silva ◽  
Manoel da Cruz Barbosa Neto ◽  
Rayane Karoline Melo Diniz ◽  
Renate Maria Ramos Wellen ◽  
...  
Keyword(s):  
Crystallization Rate ◽  
Nucleating Agent ◽  
Scanning Calorimetry ◽  
Sem Images ◽  
Dsc Studies ◽  
Heating And Cooling ◽  
Internal Mixer ◽  
Zno And Tio2 Nanoparticles ◽  
Fractured Surface ◽  
Scanning Electron

ABSTRACT PHB/TiO2 and PHB/ZnO compounds were prepared in a laboratory internal mixer. Crystallization was investigated by differential scanning calorimetry (DSC) with heating and cooling rates ranging from 5 to 30 °C/min. Fractured surface of selected samples was analysed by scanning electron microscopy (SEM). From the SEM images, it was observed that ZnO and TiO2 nanoparticles were properly dispersed in the PHB matrix. DSC studies revealed that the addition of TiO2 and ZnO changed the temperature and crystallization rate but did not affect the total crystallinity significantly. In general, TiO2 behaved as nucleating agent greatly influencing the PHB crystallization.

Incorporation of Multi Wall Carbon Nanotubes into Glass-Surfaces via Laser-Treatment

2003 ◽  
Vol 772 ◽  
Author(s):  
T. Seeger ◽  
G. de la Fuente ◽  
W.K. Maser ◽  
A.M. Benito ◽  
A. Righi ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Continuous Wave ◽  
Silica Surface ◽  
Multi Wall Carbon Nanotubes ◽  
Composite Formation ◽  
Multi Walled Carbon Nanotubes ◽  
Glass Surfaces ◽  
Walled Carbon Nanotubes ◽  
First Time ◽  
Scanning Electron

AbstractCarbon nanotubes (CNT) are interesting candidates for the reinforcement in robust composites and for conducting fillers in polymers due to their fascinating electronic and mechanical properties. For the first time, we report the incorporation of multi walled carbon nanotubes (MWNTs) into silica-glass surfaces by means of partial surface-melting caused by a continuous wave Nd:YAG laser. MWNTs were detected being well incorporated in the silica-surface. The composites are characterized using scanning electron microscopy (SEM) and Raman-spectroscopy. A model for the composite-formation is proposed based on heatabsorption by MWNTs and a partial melting of the silica-surface.

SCANNING ELECTRON MICROSCOPE: POSSIBILITIES FOR STUDYING KIDNEY DISEASES

2020 ◽  
pp. 176-182
Author(s):  
Mamaeva S.N. ◽  
Vinokurov R.R. ◽  
Munkhalova Ya.A. ◽  
Dyakonova D.P. ◽  
Platonova V.A. ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Filtration Rate ◽  
Kidney Diseases ◽  
First Time ◽  
Scanning Electron

Currently, due to the intensive development of high-tech science-intensive medical and research devices, more and more attention is paid to the development of diagnostics of rare and difficult to diagnose diseases. It is known that among numerous nephropathies, hematuria may be the only symptom of kidney and urinary tract diseases, which complicates their diagnosis and treatment. In order to develop new approaches for the diagnosis of nephropathies, the authors have been studying the morphology of red blood cells in the blood and urine of children and adults using a scanning electron microscope for several years. The paper presents the results of studies of children with various kidney diseases, including IgA-nephropathy, and chronic glomerulonephritis. Scanning electron microscopy was used for the first time to detect nanoparticles on the surface of red blood cells, the size of which is comparable to the size of viruses, which became the basis for one of the authors ' assumptions, namely, the possible transport of certain types of viruses by red blood cells. Thus, some kidney diseases could be considered virus-associated. This paper presents for the first time the results of determining the glomerular filtration rate of both kidneys separately in the study of separate kidney function and of the study of urine smears obtained during catheterization of the ureters in patients with hydronephrosis of one of the kidneys by scanning electron microscopy. As in previous studies, nanoparticles were found on the surface of red blood cells, which leads to the conclusion about the possible viral nature of the disease of the considered patient. In addition, smear images obtained using a microscope showed a significant difference in the elements of the right and left kidneys urine, which did not contradict the data on the study of glomerular filtration rate. According to the authors, the capabilities of the scanning electron microscope can be applied in fundamental research of kidney diseases at the cellular and molecular levels, forming new ideas about their origin, as well as on the basis of which new methods of non-invasive diagnostics can be built.

Natrophosphate from the Ilímaussaq alkaline complex, South Greenland

2001 ◽  
pp. 139-141
Author(s):  
Ole V. Petersen ◽  
Alexander P. Khomyakov ◽  
Henning Sørensen
Keyword(s):  
Refractive Index ◽  
Kola Peninsula ◽  
Unit Cell Parameter ◽  
Cell Parameter ◽  
Water Soluble ◽  
Type Locality ◽  
Drill Core ◽  
Alkaline Complex ◽  
First Time ◽  
Alkaline Complexes

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Petersen, O. V., Khomyakov, A. P., & Henning. (2001). Natrophosphate from the Ilímaussaq alkaline complex, South Greenland. Geology of Greenland Survey Bulletin, 190, 139-141. https://doi.org/10.34194/ggub.v190.5184 _______________ The rare mineral natrophosphate has been identified for the first time in the Ilímaussaq alkaline complex in a drill core from the Kvanefjeld area. It occurs sparsely in zoned veinlets with cores of natrophosphate and borders of fibrous trona. The natrophosphate is more or less smoky, transparent and unaltered. The refractive index n = 1.448 ± 0.005 is low compared to that given for the material from the type locality, Khibina alkaline complex, Kola Peninsula; the unit cell parameter a = 27.76 ± 0.05 Å is in excellent agreement with that given for the material from the type locality. The veins occur in hyper-agpaitic naujakasite lujavrite; villiaumite is an associated mineral. Only a few water-soluble minerals have so far been found in the Ilímaussaq alkaline complex compared to the wealth of such minerals in the Khibina and Lovozero alkaline complexes. This is possibly at least partly due to lack of necessary precautions during sampling.

Fenofibrate Solid Dispersion for Improving Oral Bioavailability: Preparation, and Characterization and in vivo Evaluation

2020 ◽  
Vol 13 (5) ◽  
pp. 5102-5109
Author(s):  
Venu Madhav K ◽  
Somnath De ◽  
Chandra Shekar Bonagiri ◽  
Sridhar Babu Gummadi
Keyword(s):  
Oral Bioavailability ◽  
Oral Delivery ◽  
Solid Dispersions ◽  
In Vitro Release ◽  
Aqueous Solubility ◽  
Water Soluble ◽  
Scanning Calorimetry ◽  
In Vivo Evaluation

Fenofibrate (FN) is used in the treatment of hypercholesterolemia. It shows poor dissolution and poor oral bioavailability after oral administration due to high liphophilicity and low aqueous solubility. Hence, solid dispersions (SDs) of FN (FN-SDs) were develop that might enhance the dissolution and subsequently oral bioavailability. FN-SDs were prepared by solvent casting method using different carriers (PEG 4000, PEG 6000, β cyclodextrin and HP β cyclodextrin) in different proportions (0.25%, 0.5%, 0.75% and 1% w/v). FN-SDs were evaluated solubility, assay and in vitro release studies for the optimization of SD formulation. Differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM) analysis was performed for crystalline and morphology analysis, respectively. Further, optimized FN-SD formulation evaluated for pharmacokinetic performance in Wistar rats, in vivo in comparison with FN suspension.  From the results, FN-SD3 and FN-SD6 have showed 102.9 ±1.3% and 105.5±3.1% drug release, respectively in 2 h. DSC and PXRD studies revealed that conversion of crystalline to amorphous nature of FN from FT-SD formulation. SEM studies revealed the change in the orientation of FN when incorporated in SDs. The oral bioavailability FN-SD3 and FN-SD6 formulations exhibited 2.5-folds and 3.1-folds improvement when compared to FN suspension as control. Overall, SD of FN could be considered as an alternative dosage form for the enhancement of oral delivery of poorly water-soluble FN.

Solubility Enhancement of Poorly Water-Soluble Antifungal Drug Acyclovir by Nanocrystal Formulation Approach

2018 ◽  
Vol 11 (2) ◽  
pp. 4036-4042
Author(s):  
Prakash Goudanavar ◽  
Ankit Acharya ◽  
Vinay C.H
Keyword(s):  
Chemical Interaction ◽  
Research Work ◽  
Antiviral Drug ◽  
In Vitro Release ◽  
Oral Route ◽  
Water Soluble ◽  
Precipitation Method ◽  
Dsc Studies ◽  
Ft Ir

Administration of an antiviral drug, acyclovir via the oral route leads to low and variable bioavailability (15-30%). Therefore, this research work was aimed to enhance bioavailability of acyclovir by nanocrystallization technique. The drug nanocrystals were prepared by anti-solvent precipitation method in which different stabilizers were used. The formed nanocrystals are subjected to biopharmaceutical characterization including solubility, particle size and in-vitro release. SEM studies showed nano-crystals were crystalline nature with sharp peaks. The formulated drug nanocrystals were found to be in the range of 600-900nm and formulations NC7 and NC8 showed marked improvement in dissolution velocity when compared to pure drug, thus providing greater bioavailability. FT-IR and DSC studies revealed the absence of any chemical interaction between drug and polymers used. 

Sign in / Sign up

Export Citation Format

Share Document