Search results for "Facta"
showing 10 items of 400 documents
Bioadhesive Matrix Tablets Loaded with Lipophilic Nanoparticles as Vehicles for Drugs for Periodontitis Treatment: Development and Characterization
2019
Periodontitis treatment is usually focused on the reduction or eradication of periodontal pathogens using antibiotics against anaerobic bacteria, such as metronidazole (MTR). Moreover, recently the correlation between periodontal diseases and overexpression of reactive oxygen species (ROS) led to the introduction of antioxidant biomolecules in therapy. In this work, bioadhesive buccal tablets, consisting of a hydrophilic matrix loaded with metronidazole and lipophilic nanoparticles as a vehicle of curcumin, were developed. Curcumin (CUR)-loaded nanostructured lipid carriers (NLC) were prepared using glycyrrhetic acid, hexadecanol, isopropyl palmitate and Tween®
Microemulsions: Phase transitions and their dynamics
2007
By differential scanning microcalorimetry we investigate temperature-induced phase transitions and their dynamics in mixtures of water, oil and a non-ionic surfactant. Special emphasis is on an investigation of the transition from a lamellar to a microemulsion phase and on the emulsification failure. The first-order phase transition from a lamellar to a microemulsion phase leads to heat changes up to 1k BT per surfactant molecule. These large values for the latent heat are quantitatively described by an interfacial model which takes into account the temperature dependence of the spontaneous curvature.
Binding of Short Alkyl Chain Surfactants to the (Ethylene oxide)13−(Propylene oxide)30−(Ethylene oxide)13and (Ethylene oxide)75−(Propylene oxide)30−(…
2002
The enthalpy of transfer (ΔHt) of neutral copolymers, at a fixed and low concentration ca. 10-3 mol kg-1, from water to the aqueous surfactant solutions as a function of the surfactant concentration (fSmS) was determined at 25 °C. The surfactants studied are sodium octanoate, sodium decanoate, N-octylpyridinium chloride (OPC), and N,N-dimethyloctylamine-N-oxide (ODAO). The copolymers are (ethylene oxide)13−(propylene oxide)30−(ethylene oxide)13 (L64) and (ethylene oxide)75−(propylene oxide)30−(ethylene oxide)75 (F68). The two copolymers show different hydrophilic−hydrophobic ratios, the larger being for F68. As a general feature, the shape of the ΔHt vs fSmS curve depends on the nature of t…
Quantitative determination of octylphenol, nonylphenol, alkylphenol ethoxylates and alcohol ethoxylates by pressurized liquid extraction and liquid c…
2007
6 páginas, 1 figura, 2 tablas.
Pulmonary surfactant protein C containing lipid films at the air-water interface as a model for the surface of lung alveoli.
1995
The pulmonary surfactant lines as a complex monolayer of lipids and proteins the alveolar epithelial surface. The monolayer dynamically adapts the surface tension of this interface to the varying surface areas during inhalation and exhalation. Its presence in the alveoli is thus a prerequisite for a proper lung function. The lipid moiety represents about 90% of the surfactant and contains mainly dipalmitoylphosphatidylcholine (DPPC) and phosphatidylglycerol (PG). The surfactant proteins involved in the surface tension adaption are called SP-A, SP-B and SP-C. The aim of the present investigation is to analyse the properties of monolayer films made from pure SP-C and from mixtures of DPPC, DP…
Langmuir monolayers and Langmuir–Blodgett films of ferritin prepared by using a surfactant mixture of eicosylamine (EA) and methyl stearate (SME)
2007
Abstract Magnetic Langmuir–Blodgett films of ferritin have been prepared by using the adsorption properties of a 1/4 mixed monolayer of eicosylamine (EA) and methyl stearate (SME). BAM images show that a more homogeneous distribution of ferritin at the air–water interface is achieved by using this mixture of surfactants instead of the DODA/SME mixed matrix of a previous work. Transfer of the monolayer onto different substrates allowed the preparation of multilayer LB films. Infrared and UV–Vis spectroscopies indicate that ferritin molecules are incorporated within the LB films. Furthermore, UV–Vis spectroscopy measurements reveal that the amount of ferritin incorporated into these LB film h…
Fluorescence Microscopy Studies of Structure Formation in Surfactant Monolayers
1993
Monolayers of water-insoluble surfactants (Langmuir monolayers) are important model system in basic research for studying the self-organization of organic molecules into two-dimensional layers [1, 2]. These floating films are also the basis for the build-up of complex multilayered structures on solid substrates, so-called Langmuir—Blodgett films (LB-films), which are of considerable interest in fundamental science and promise some future practical applications [3].
Exploring the co-loading of lidocaine chemical forms in surfactant/phospholipid vesicles for improved skin delivery
2015
Abstract Objectives The present study was aimed at targeting the skin to deliver lidocaine loaded in surfactant/phospholipid vesicles tailored for improved local delivery. The influence of different formulation parameters was explored to maximise drug efficacy. Methods The vesicles were prepared using a mixture of soy lipids (Phospholipon 50) and a surfactant with penetration-enhancing properties (Oramix CG110, Labrasol, Labrafac PG or Labrafac CC), and loaded with lidocaine. The formulations were analysed in detail by cryo-TEM, SAXS, Turbiscan Lab, and tested in permeation experiments through new born pig skin, as a function of the chemical form and concentration of lidocaine (i.e. free ba…
Liposome Formation from Bile Salt–Lipid Micelles in the Digestion and Drug Delivery Model FaSSIFmod Estimated by Combined Time-Resolved Neutron and D…
2011
The flow of bile secretion into the human digestive system was simulated by the dilution of a bile salt-lipid micellar solution. The structural development upon the dilution of the fed state bile model FeSSIF(mod6.5) to the fasted state bile model FaSSIF(mod) was investigated by small-angle neutron scattering (SANS) and dynamic light scattering (DLS) in crossed beam experiments to observe small and large structures in a size range of 1 nm to 50 μm in parallel. Because of the physiologically low lipid and surfactant concentrations of 2.625 mM egg-phosphatidylcholine and 10.5 mM taurocholate the sensitivity of the neutron-structural investigations was improved by partial solvent deuteration w…
Palmitoylation of Pulmonary Surfactant Protein SP-C Is Critical for Its Functional Cooperation with SP-B to Sustain Compression/Expansion Dynamics in…
2010
AbstractRecent data suggest that a functional cooperation between surfactant proteins SP-B and SP-C may be required to sustain a proper compression-expansion dynamics in the presence of physiological proportions of cholesterol. SP-C is a dually palmitoylated polypeptide of 4.2 kDa, but the role of acylation in SP-C activity is not completely understood. In this work we have compared the behavior of native palmitoylated SP-C and recombinant nonpalmitoylated versions of SP-C produced in bacteria to get a detailed insight into the importance of the palmitic chains to optimize interfacial performance of cholesterol-containing surfactant films. We found that palmitoylation of SP-C is not essenti…