scholarly journals Effect of Hydrophilic Polymers on Complexation Efficiency of Cyclodextrins in Enhancing Solubility and Release of Diflunisal

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1564
Author(s):  
Mehreen Bashir ◽  
Haroon Khalid Syed ◽  
Sajid Asghar ◽  
Muhammad Irfan ◽  
Waleed Hassan Almalki ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Drug Release ◽  
Weight Ratio ◽  
Hydrophilic Polymers ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Kneading Method ◽  
Carboxymethyl Cellulose Sodium ◽  
Cyclodextrin Cavity

The effects of three hydrophilic polymers, namely, carboxymethyl cellulose sodium (CMC-Na), polyvinyl alcohol (PVA) and poloxamer-188 (PXM-188) on the solubility and dissolution of diflunisal (DIF) in complexation with β-cyclodextrin (βCD) or hydroxypropyl β-cyclodextrin (HPβCD), were investigated. The kneading method was used at different drug to cyclodextrin weight ratios. Increases in solubility and drug release were observed with the DIF/βCD and DIF/HPβCD complexes. The addition of hydrophilic polymers at 2.5, 5.0 and 10.0% w/w markedly improved the complexation and solubilizing efficiency of βCD and HPβCD. Fourier-transform infrared (FTIR) showed that DIF was successfully included into the cyclodextrin cavity. Differential scanning calorimetry (DSC) and X-ray diffractometry (XRD) confirmed stronger drug amorphization and entrapment in the molecular cage of cyclodextrins. The addition of PVA, CMC-Na or PXM-188 reduced further the intensity of the DIF endothermic peak. Most of the sharp and intense peaks of DIF disappeared with the addition of hydrophilic polymers. In conclusion, PXM-188 at a weight ratio of 10.0% w/w was the best candidate in enhancing the solubility, stability and release of DIF.

Hydriding Behaviour of Mg-C Nanocomposites

2003 ◽  
Vol 801 ◽  
Author(s):  
A. Bassetti ◽  
E. Bonetti ◽  
A. L. Fiorini ◽  
J. Grbovic ◽  
A. Montone ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Weight Ratio ◽  
Hydrogen Desorption ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Carbon Nanocomposites ◽  
X Ray ◽  
Scanning Electron

ABSTRACTMagnesium carbon nanocomposites for hydrogen storage have been synthesized by ball milling with different amount of benzene, acting as a lubricant. Their microstructure has been studied by X-ray diffraction and scanning electron microscopy, while the hydrogen desorption temperature has been tested by differential scanning calorimetry. Experimental results show that the microstructure after milling, the hydrogenation capabilities of the material and the reactivity with the air are related to the amount of additives. In particular the carbon to benzene ratio seems to play a major role. In fact, with an optimum value of carbon to benzene weight ratio of 1/6, the amount of carbon being 15 wt% of the milled mixture, a decomposition heat equal to 57% of pure MgH2 was measured, even after air manipulation of the sample.

scholarly journals Pengaruh Bentonit terhadap Pembentukan Fasa Polimorf dan Sifat Termal Membran Hibrida Poliviniliden Fluorida/Bentonit

2021 ◽  
Vol 17 (2) ◽  
pp. 177
Author(s):  
Edi Pramono ◽  
Rosid Eka Mustofa ◽  
Ozi Adi Saputra ◽  
Yulianto Adi Nugroho ◽  
Deana Wahyunigrum ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Thermal Properties ◽  
Phase Formation ◽  
Attenuated Total Reflectance ◽  
Hybrid Membranes ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Total Reflectance ◽  
X Ray

<p>Kajian struktur dan degradasi termal pada membran hibrida poliviniliden fluorida (PVDF)/lempung bentonit (BNT) telah dilakukan. Penelitian ini bertujuan mengetahui pengaruh penambahan BNT terhadap pembentukan fasa PVDF dan sifat termalnya. Membran hibrida PVDF/lempung BNT dibuat dengan metode inversi fasa. Membran yang dihasilkan dikarakterisasi dengan <em>attenuated total reflectance fourier transform infrared</em> (ATR-FTIR), <em>x-ray diffraction</em> (XRD), dan <em>differential scanning calorimetry</em> (DSC). Hasil penelitian menunjukkan membran PVDF/BNT memiliki struktur polimorf PVDF fasa α dan β yang terkonfirmasi dari data FTIR dan XRD. Data DSC menunjukkan penurunan nilai titik leleh (Tm) dengan penambahan BNT, dan dengan rentang suhu pelelehan yang lebih kecil. Kristalisasi PVDF terjadi secara isothermal dan adanya BNT menghasilkan titik kristalisasi (Tc) pada suhu yang lebih tinggi dibandingkan membran PVDF murni. Analisis termal dengan DSC memberikan informasi komprehensif pelelehan dan kristalisasi dari polimorf PVDF pada matriks membran.</p><p id="docs-internal-guid-c92edf53-7fff-cf03-76f3-f207f37c74f5" style="line-height: 1.2; text-align: justify; margin-top: 6pt; margin-bottom: 6pt;" dir="ltr"><strong>Effect of Bentonite toward Polymorph Phase Formation and Thermal Properties of Polyvinylidene Fluoride/Bentonite Hybrid Membranes. </strong>The study of the structure and thermal properties of PVDF/bentonite (BNT) hybrid membranes has been carried out. This study aims to determine the effect of BNT addition on the phase formation and thermal properties of the PVDF. In this study, PVDF/BNT hybrid membranes were prepared through the phase inversion method. The resulting membrane was characterized by Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR), x-ray diffraction (XRD), and differential scanning calorimetry (DSC). The results showed that the PVDF/BNT membrane has a PVDF polymorph structure with α and β phases confirmed by FTIR and XRD data. The DSC data showed that the addition of BNT decrease of the melting point (Tm) and with a smaller melting temperature range. PVDF polymorph crystallization occurs isothermally and the presence of BNT produces a crystallization point (Tc) at a higher temperature than pristine PVDF membrane. Thermal analysis with DSC provides comprehensive information on melting and crystallization of PVDF polymorphs in the membrane matrix.</p>

scholarly journals Combination of Zinc Hyaluronate and Metronidazole in a Lipid-Based Drug Delivery System for the Treatment of Periodontitis

Pharmaceutics ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 142 ◽  
Author(s):  
Attila Léber ◽  
Mária Budai-Szűcs ◽  
Edit Urbán ◽  
Péter Vályi ◽  
Attila Gácsi ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Drug Release ◽  
Sustained Release ◽  
Antimicrobial Effect ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Prevalent Disease ◽  
Swelling Mechanism ◽  
Oral Pathogens

Background: Despite being a highly prevalent disease and a possible contributor to adult tooth loss, periodontitis possesses no well-established therapy. The aim of the recent study was the development and evaluation of a mucoadhesive monophase lipid formulation for the sustained local delivery of amoxicillin, metronidazole, and/or zinc hyaluronate or gluconate. Methods: To investigate our formulations, differential scanning calorimetry, X-ray diffraction, swelling, erosion, mucoadhesivity, drug release, and antimicrobial measurements were performed. Results: Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) results show that the loaded drugs are in a suspended form, the softening of the formulations starts at body temperature, but a part remains solid, providing sustained release. Swelling of the lipid compositions is affected by the hydrophilic components, their concentration, and the strength of the coherent lipid structure, while their erosion is impacted by the emulsification of melted lipid components. Conclusions: Results of drug release and antimicrobial effectiveness measurements show that a sustained release may be obtained. Amoxicillin had higher effectiveness against oral pathogens than metronidazole or zinc hyaluronate alone, but the combination of the two latter could provide similar effectiveness to amoxicillin. The applied mucoadhesive polymer may affect adhesivity, drug release through the swelling mechanism, and antimicrobial effect as well.

scholarly journals Progressive Steps of Polymorphic Transformation of Gabapentin Polymorphs Studied by Hot-stage FTIR Microspectroscopy

2010 ◽  
Vol 13 (1) ◽  
pp. 67 ◽  
Author(s):  
Cheng-Hung Hsu ◽  
Wen-Ting Ke ◽  
Shan-Yang Lin
Keyword(s):  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Solid State ◽  
Polymorphic Transformation ◽  
Three Dimensional ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ftir Microspectroscopy ◽  
Peak Intensity ◽  
One Step

Purpose. The aim of this study was to determine the progressive processes of polymorphic transformation of different gabapentin (GBP) polymorphs by using hot-stage Fourier transform infrared (FTIR) microspectroscopy. Methods. Four polymorphs of GBP were previously prepared and then identified by differential scanning calorimetry (DSC), thermogravimetric (TG) analysis, FTIR microspectroscopy and X-ray powder diffractometry. A novel hot-stage FTIR microspectroscopic technique was used to investigate the progressive steps of polymorphic transformation of each GBP polymorph sealed within two pieces of KBr plates. Results. Four polymorphs (Forms I, II, III and IV) of GBP were well characterized. The GBP form I was proven to be a monohydrate, but other GBP forms II-IV were anhydrous. Different thermal-induced progressive processes and steps of polymorphic interconversion of GBP polymorphs were clearly found from the changes in the three-dimensional IR spectral contour and peak intensity by using hot-stage FTIR microspectroscopy. The results also indicate that GBP form I was dehydrated and transformed to form III, and then converted to form IV; whereas GBP forms II and III directly transformed to form IV during heating. The GBP form IV was the last polymorph before the intramolecular lactamization of GBP. Conclusion. A one-step novel hot-stage FTIR microspectroscopy was successfully applied to simultaneously and continuously investigate the progressive processes and steps of thermal-induced polymorphic interconversion of GBP polymorph in the solid state.

scholarly journals Extraction of Lignin from Empty Fruit Bunch Fiber via Microwave-Assisted Acid Hydrotrope Solvent

2021 ◽  
Vol 1 (2) ◽  
pp. 26-33
Author(s):  
Rasidi Roslan ◽  
Muhammad Nor Arifin Yaakob ◽  
Ms Fathihah
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Reaction Time ◽  
Thermogravimetric Analysis ◽  
Empty Fruit Bunch ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Microwave Assisted

Lignin is a sub-product from lignocellulose apart from cellulose and hemicellulose that produced from empty fruit bunch fiber (EFB). Lignin has low solubility and reactivity due to its bulky macromolecule structre. Being one of the wastes that being generated in massive amount, many alternatives has been taken to transform lignin into valuable products. To do so, many reactions are needed for the lignin to go through. In this study, lignin will be extracted from empty fruit bunch (EFB) with the aid of acid hydrotrope concentration of 30 % and microwave assisted with various extraction heating time and temperature. Characterization of lignin is done using Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric analysis (TGA), Differential Scanning Calorimetry (DSC) and Nuclear magnetic resonance (NMR) while Scanning Electron Microscopy (SEM) and X-ray Powder Diffraction (XRD) used to characterize residues. The highest percentage of lignin yield and its purity obtained are 19.47 % and 96.63 % with the reaction time and temperature of the microwave is 30 minutes and 90 °C. From Fourier Transform Infrared Spectroscopy (FTIR), a wide band at 3430.09 cm-1 and 3413.45 cm-1 are observed due to O-H stretching vibration. As for peak at 1123.17 cm-1 and 1051.26 cm-1, it correspond to syringyl and guaicyl unit in both lignin and raw EFB. As for Thermogravimetric analysis (TGA), it shows that lignin decomposes slowly compared to raw EFB due to the aromatic structure of lignin that is very stable, therefore leading to difficulty of decomposing while from Differential Scanning Calorimetry (DSC), after removing cellulose and hemicellulose, glass transition temperature (Tg) obtained from lignin DSC spectroscopy is 193.05 °C at heat flow of 1.15 mW/mg. Next, from Nuclear magnetic resonance (NMR) spectroscopy, the signals observed around 6.5 – 8.0 ppm indicate aromatic H in syringyl and guaiacyl unit only at lignin spectra while at 3.3 – 4.0 ppm, raw EFB has an intense peak compared to lignin which attribute to methoxyl group. When the residue of the lignin as well as the raw EFB powder is characterized using X-ray Powder Diffraction (XRD), the crystallinity index of the lignin with reaction time and temperature of the microwave 30 minutes and 90 °C is the highest, 69.28 %. As a conclusion, an admissible percent of lignin yield and purity is able to be obtained with addition of acid hydrotrope depending on the variables. From the spectroscopies characterization, it is proved that lignin characteristics and properties are compatible for the production of new and value added products.

Synthesis of Ethylene-Propylene Copolymer and their Structures

2014 ◽  
Vol 1035 ◽  
pp. 149-154
Author(s):  
Yan Liu Dang ◽  
Yun Zhao ◽  
Chao Xiang Wang ◽  
Qing Ze Jiao ◽  
Han Sheng Li ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Glass Transition ◽  
Resonance Spectroscopy ◽  
Differential Scanning Calorimetry Analysis ◽  
Scanning Calorimetry ◽  
Glass Transition Temperatures ◽  
Ethylene Propylene ◽  
X Ray

This work reports copolymerization of ethylene-propylene (EP) using a novel phenoxy–ester ligated titanium catalyst. Copolymerization reactions were conducted in toluene at 70 °C with varied E/P flow ratios. Fourier transform infrared spectroscopy, X-ray diffractometer, nuclear magnetic resonance spectroscopy and differential scanning calorimetry analysis were performed to characterize the structures, compositions and glass transition temperatures of the copolymers. The results show that ethylene-propylene copolymers are random polymers and the link ratios of ethylene to propylene are between 0.89 and 1.26. The glass transition temperature of ethylene-propylene copolymer is-43.3 °C.

scholarly journals Development and Characterization of Nanostructured Pharmacosomal Mesophases: An Innovative Delivery System for Bioactive Peptides

2018 ◽  
Vol 8 (4) ◽  
pp. 609-615 ◽  
Author(s):  
Maryam Rezvani ◽  
Javad Hesari ◽  
Seyed Hadi Peighambardoust ◽  
Maria Manconi ◽  
Hamed Hamishehkar
Keyword(s):  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Small Angle ◽  
Bioactive Peptides ◽  
Polarized Light ◽  
Scanning Calorimetry ◽  
X Ray ◽  
X Ray Scattering

Purpose: To potentially enhance the bioavailability and extend the bioactivity effectiveness of Isoleucine-Proline-Proline (IPP, an antihypertensive bioactive peptide of dairy origin), a novel Lyotropic Liquid Crystalline Pharmacosomal Nanoparticle (LLCPNP) was synthesized, and its physicochemical and technological characteristics were studied. Methods: LLCPNPs precursors were developed using IPP and soy phosphatidylcholine via complex formation. Polarized light microscopy, small angle X-ray scattering, differential scanning calorimetry, dynamic light scattering and Fourier transform infrared spectroscopy were employed to characterize the physicochemical properties of the nanoparticles. The in-vitro release and its related mechanisms were also studied. Results: Fourier transform infrared spectroscopy confirmed the complexation between the components of LLCPNPs. Phase behavior evaluation by polarized light microscope showed the characteristic birefringent texture. These findings along with those of small angle X-ray scattering and differential scanning calorimetry proved the formation of lamellar LLCPNPs. These particles represented nanometric size (<100 nm), high incorporation efficiency (93.72%) and proper physicochemical stability during long-term storage. In-vitro studies demonstrated a sustained release behavior fitted to non-Fickian diffusion and Higuchi kinetic models. Conclusion: The present study results emphasized that LLCPNPs could be proposed as an unrivaled carrier to promote the bioavailability, stability and shelf-life of nutraceutical and biopharmaceutical formulations containing bioactive peptides.

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