Search results for "solubility"
showing 10 items of 681 documents
Chitosomes as drug delivery systems for C-phycocyanin: preparation and characterization.
2010
The aim of this work was to investigate chitosomes, i.e. liposomes coated by a polyelectrolyte complex between chitosan (CH) and xantan gum (XG), as potential delivery system for oral administration of the protein C-phycocyanin. To this purpose several CH-XG-microcomplexes were prepared in aqueous lactic acid at different chitosan-xanthan gum percent ratios and rheological properties of the microcomplexes were studied to analyse the contribution of chitosan and xanthan gum in the reaction of microcomplexation. After establishing the best microcomplexes, chitosomes were prepared by coating C-phycocyanin loaded liposomes with the CH-XG hydrogels using spray-drying or freeze-drying. The chitos…
Different Dissolution Media Lead to Different Crystal Structures of Talinolol with Impact on Its Dissolution and Solubility
2003
During the performance of dissolution tests with immediate and controlled-release talinolol tablets it was detected that the type of the buffer used as dissolution medium had a strong influence on the solubility and the dissolution behavior of the drug. It was proven that talinolol appeared in different crystal structures with strongly differing solubilities when pure water, acetate, or phosphate buffers were employed as dissolution media. The resulting crystal structures were characterized by means of light microscopy, differential scanning calorimetry, and X-ray powder diffraction. All methods were adjuvant to detect changes in talinolol crystal structures. The different solubility and di…
Solubilized liver extracellular matrix maintains primary rat hepatocyte phenotype in-vitro.
2015
Whole organ engineering and cell-based regenerative medicine approaches are being investigated as potential therapeutic options for end-stage liver failure. However, a major challenge of these strategies is the loss of hepatic specific function after hepatocytes are removed from their native microenvironment. The objective of the present study was to determine if solubilized liver extracellular matrix (ECM), when used as a media supplement, can better maintain hepatocyte phenotype compared to type I collagen alone or solubilized ECM harvested from a non-liver tissue source. Liver extracellular matrix (LECM) from four different species was isolated via liver tissue decellularization, solubil…
Water-Soluble Polymers Coupled with Glycopeptide Antigens and T-Cell Epitopes as Potential Antitumor Vaccines
2013
Highly decorated: Tumor-associated MUC1 glycopeptide and tetanus toxoid T-cell epitope P2 can be attached to water-soluble poly(N-(2-hydroxypropyl)methacrylamide) carriers by orthogonal ligation techniques. Fully synthetic vaccine A with additional nanostructure-promoting domains induced antibodies that exhibit high affinity to tumor cells.
Source and Nature of Inhaled Atmospheric Dust from Trace Element Analyses of Human Bronchial Fluids
2011
International audience; Rapid volcanic eruptions quickly ejecting large amounts of dust provoke the accumulation of heavy metals in people living in surrounding areas. Analyses of bronchoalveolar lavage samples (BAL) collected from people exposed to the paroxysmal 2001 Etna eruption revealed a strong enrichment of many toxic heavy metals. Comparing the BAL to the dust composition of southeastern Sicily, we found that only V, Cr, Mn, Fe, Co, and U enrichment could be related to the volcanic event, whereas Ni, Cu, Cd, and Pb contents come from the dissolution of particles of anthropogenic origin. Furthermore, the nature of these inhaled anthropogenic particles was revealed by anomalous La and…
Evolution of the taste of a bitter camembert cheese during ripening : characterization of a matrix effect
2001
The objective of this study was to characterize the effect of ripening on the taste of a typically bitter Camembert cheese. The first step was to select a typically bitter cheese among several products obtained by different processes supposed to enhance this taste defect. Second, the evolution of cheese taste during ripening was characterized from a sensory point of view. Finally, the relative impact of fat, proteins, and water-soluble molecules on cheese taste was determined by using omission tests performed on a reconstituted cheese. These omission tests showed that cheese taste resulted mainly from the gustatory properties of water-soluble molecules but was modulated by a matrix effect d…
Taste active compounds in a goat cheese water-soluble extract 1. Development and sensory validation of a model water-soluble extract
2000
The aim of this study was to evaluate the impact of the components of a goat cheese water-soluble extract (WSE) on its flavor by both physicochemical and sensory techniques with special emphasis on taste. After characterization of the organoleptic properties of the cheese, the WSE was extracted with pure water and submitted to successive tangential ultrafiltrations and nanofiltration. The physicochemical assessment of these fractions led to the constitution of a model mixture (MWSE) compared by sensory evaluation to the crude WSE, using a panel of 16 trained members. The results of both sensory profile and triangular tests indicate no significant difference, therefore proving that the recon…
Taste active compounds in a goat cheese water-soluble extract 2. Determination of the relative impact of water-soluble extract components on its tast…
2000
The aim of this work was to determine the relative impact of water-soluble compounds on the gustatory properties of a goat cheese water-soluble extract (WSE). Using a semisynthetic model mixture (MWSE) previously elaborated in physicochemical and gustatory accordance with the cheese WSE (see part 1, Engel et al. J. Agric. Food Chem. 2000, 48, 4252-4259), omission tests were performed. Among the main taste characteristics of the WSE (salty, sour, and bitter), saltiness was explained by an additive contribution of sodium, potassium, calcium, and magnesium cations, whereas sourness was mainly due to a synergistic effect involving sodium chloride, phosphates, and lactic acid and bitterness was …
Synthesis of molecularly uniform model oligomers for 1,5-naphthalene diisocyanate and 1,4-butanediol based polyurethanes by using the 3,5-di-tert-but…
1997
A modified benzyloxycarbonyl (BOC) protective group, the 3,5-di-tert-butyl substituted BOC (3,5-tBBOC) group, was introduced to the stepwise synthesis of molecularly uniform oligourethanes based on 1,5-naphthalene diisocyanate (NDI) and 1,4-butanediol (BDO) for the protection of the amino functions of the starting material 1,5-naphthalene-diamine (NDA). The tert-butyl substituents of the 3,5-tBBOC group significantly improved the solubility of the intermediate products in the oligourethane synthesis. Thus, applying this modified protective group, reactions could be carried out, which were not possible with the conventional BOC group, due to the insolubility of the compounds in all suitable …
A thermodynamic approach to study hydrogen-bonding interactions in solvent/solvent/polymer ternary systems
2007
Abstract A thermodynamic approach based on both the classical Flory–Huggins (FH) formalism and the association equilibria (AE) theory has been developed to study the solubility properties of a system formed by a proton-donor solvent (A), a proton-acceptor solvent (B) and a proton-acceptor polymer (C). The miscibility of this ternary system is attained by competitive specific interactions via hydrogen-bonding established between the hydroxyl and carbonyl interacting groups of either solvent–solvent (AB) or solvent–polymer (AC) system components. The binary AB and AC specific interactions and their dependence with the system composition as well as with the extent of the association equilibriu…