| People | Locations | Statistics |
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| Naji, M. |
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| Motta, Antonella |
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| Aletan, Dirar |
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| Mohamed, Tarek |
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| Ertürk, Emre |
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| Taccardi, Nicola |
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| Kononenko, Denys |
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| Petrov, R. H. | Madrid |
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| Alshaaer, Mazen | Brussels |
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| Bih, L. |
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| Casati, R. |
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| Muller, Hermance |
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| Kočí, Jan | Prague |
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| Šuljagić, Marija |
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| Kalteremidou, Kalliopi-Artemi | Brussels |
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| Azam, Siraj |
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| Ospanova, Alyiya |
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| Blanpain, Bart |
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| Ali, M. A. |
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| Popa, V. |
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| Rančić, M. |
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| Ollier, Nadège |
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| Azevedo, Nuno Monteiro |
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| Landes, Michael |
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| Rignanese, Gian-Marco |
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Andrade, Maria Madalena Dionísio
Universidade Nova de Lisboa
in Cooperation with on an Cooperation-Score of 37%
Topics
Publications (31/31 displayed)
- 2024Cryoprotective Polysaccharides with Ordered Gel Structures Induce Ice Growth Anticipation and Survival Enhancement during Cell Cryopreservationcitations
- 2023Study of the mesomorphic properties and conductivity of n-alkyl-2-picolinium ionic liquid crystalscitations
- 2022Polyhydroxyalkanoates from A Mixed Microbial Culturecitations
- 2022Synthesis and characterisation of ionic liquid crystals based on substituted pyridinium cationscitations
- 2021How Molecular Mobility, Physical State, and Drug Distribution Influence the Naproxen Release Profile from Different Mesoporous Silica Matricescitations
- 2021Influence of natural deep eutectic systems in water thermal behavior and their applications in cryopreservationcitations
- 2021Poly(L-lactic acid)/lithium ferrite compositescitations
- 2019A process engineering approach to improve production of P(3HB) by cupriavidus necator from used cooking oilcitations
- 2017Relaxation behavior of polyurethane networks with different composition and crosslinking densitycitations
- 2017Stabilizing Unstable Amorphous Menthol through Inclusion in Mesoporous Silica Hostscitations
- 2016Dissolution enhancement of active pharmaceutical ingredients by therapeutic deep eutectic systemscitations
- 2016Accessing the Physical State and Molecular Mobility of Naproxen Confined to Nanoporous Silica Matrixescitations
- 2015Design of controlled release systems for THEDES - Therapeutic deep eutectic solvents, using supercritical fluid technologycitations
- 2015Electrical properties of lithium ferrite nanoparticles dispersed in a styrene-isoprene-styrene copolymer matrixcitations
- 2015Dipolar motions and ionic conduction in an ibuprofen derived ionic liquidcitations
- 2014Influence of nanoscale confinement on the molecular mobility of ibuprofencitations
- 2014Conversion of fat-containing waste from the margarine manufacturing process into bacterial polyhydroxyalkanoatescitations
- 2014Ion jelly conductive properties using dicyanamide-based ionic liquidscitations
- 2014Self-standing elastomeric composites based on lithium ferrites and their dielectric behaviorcitations
- 2013New method to analyze dielectric relaxation processescitations
- 2012Probing radiation damage by alternated current conductivity as a method to characterize electron hopping conduction in DNA moleculescitations
- 2012Understanding the Ion Jelly Conductivity Mechanismcitations
- 2011Kinetics of free radical polymerization probed by dielectric relaxation spectroscopy under high conductivity conditionscitations
- 2011Molecular dynamics of poly(ATRIF) homopolymer and poly(AN-co-ATRIF) copolymer investigated by dielectric relaxation spectroscopycitations
- 2011Phase Transformations Undergone by Triton X-100 Probed by Differential Scanning Calorimetry and Dielectric Relaxation Spectroscopycitations
- 2007Dielectric and mechanical relaxation processes in methyl acrylate/tri-ethyleneglycol dimethacrylate copolymer networkscitations
- 2007Temperature modulated DSC study of the kinetics of free radical isothermal network polymerizationcitations
- 2007Origin of glassy dynamics in a liquid crystal studied by broadband dielectric and specific heat spectroscopycitations
- 2006Changes in molecular dynamics upon formation of a polymer dispersed liquid crystalcitations
- 2005Rotational Mobility in a Crystal Studied by Dielectric Relaxation Spectroscopy. An Experiment for the Physical Chemistry laboratorycitations
- 2002Dielectric studies of the nematic mixture E7 on a hdroxypropylcellulose substratecitations
Places of action
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article
Accessing the Physical State and Molecular Mobility of Naproxen Confined to Nanoporous Silica Matrixes
Abstract
<p>The pharmaceutical drug naproxen was loaded in three different silica hosts with pore diameters of 2.4 (MCM), 3.2 (MCM), and 5.9 nm (SBA), respectively: nap<sub>MCM-2.4nm</sub>, nap<sub>MCM-3.2 nm</sub>, and nap<sub>SBA-5.9 nm</sub>. To access the guest physical state in the prepared composites, differential scanning calorimetry (DSC), X-ray diffraction (XRD), and attenuated total reflectance Fourier transform infrared spectroscopy were used. The different techniques provided complementary information on a molecular population that was revealed to be distributed among different environments, namely the pore core, the inner pore wall, and the outer surface. It was found that naproxen is semicrystalline in the higher pore size matrix being able to crystallize inside pores; after melting it undergoes full amorphization. In the case of the lower pore size matrix, naproxen crystallizes outside pores due to an excess of filling while most of the remaining fraction is incorporated inside the pores as amorphous. Crystallinity in these two composites was observed by the emergence of the Bragg peaks in the XRD analysis, whereas for nap<sub>MCM-3.2 nm</sub> only the amorphous halo was detected. The latter only exhibits the step due to the glass transition by DSC remaining stable as amorphous at least for 12 months. The glass transition in the three composites is abnormally broad, shifting to higher temperatures as the pore size decreases, coherent with the slowing down of molecular mobility as probed by dielectric relaxation spectroscopy. For nap<sub>SBA-5.9 nm</sub> the dielectric response was deconvoluted in two processes: a hindered surface (S-) process due to molecules interacting with the inner pore wall and a faster α-relaxation associated with the dynamic glass transition due to molecules relaxing in the pore core, which seems a manifestation of true confinement effects. The drug incorporation inside a nanoporous matrix, mainly in 3.2 nm pores, was revealed to be a suitable strategy to stabilize the highly crystallizable drug naproxen in the amorphous/supercooled state and to control its release from the silica matrix, allowing full delivery after 90 min in basic media.</p>