References of "Delattre, Luc"
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See detailBetamethasone-in-cyclodextrin-in-liposome: The effect of cyclodextrins on encapsulation efficiency and release kinetics
Piel, Géraldine ULg; Piette, Marie ULg; Barillaro, Valery et al

in International Journal of Pharmaceutics (2006), 312(1-2), 75-82

Lipophilic drugs have limited solubility in phospholipid systems, hence maximum entrapment levels in liposomes are known to be low. "Drugs-in-cyclodextrin-in-liposome" systems were previously proposed to ... [more ▼]

Lipophilic drugs have limited solubility in phospholipid systems, hence maximum entrapment levels in liposomes are known to be low. "Drugs-in-cyclodextrin-in-liposome" systems were previously proposed to overcome this drawback but studies were limited to beta CD and HP beta CD. In some cases, other cyclodextrins may be more interesting than beta CD or HPPCD, such as methylated cyclodextrins. However, these cyclodextrins are known to extract lipid components from the lipid membrane, which may destabilize liposomes. We tested the influence of several cyclodextrins (beta CD, gamma CD, Dimeb, Trimeb, Crysmeb, Rameb, HP beta CD and HP gamma CD) on the aqueous solubility of betamethasone by phase solubility diagrams and on the encapsulation efficiency in liposomes. The release kinetics of betamethasone was studied using Franz diffusion cells. We showed that release kinetics are directly correlated with encapsulation efficiency, which is closely related to betamethasone concentration in cyclodextrin complex solution. No liposome destruction was observed, even with the testing of methylated cyclodextrins at the highest concentration (40 mM). This can be explained by the fact that these cyclodextrins have a higher affinity for betamethasone than for cholesterol. This was proved by the comparison of phase solubility diagrams of both betamethasone and cholesterol. (c) 2006 Elsevier B.V. All rights reserved. [less ▲]

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See detailInhaled fluticasone reduces bronchial responsiveness and airway inflammation in cats with mild chronic bronchitis
Kirschvink, N; Leemans, Jérôme ULg; Delvaux, François et al

in Journal of Feline Medicine and Surgery (2006), 8(1), 45-54

This study investigated the effect of inhaled fluticasone on lower airway inflammation and bronchial responsiveness (BR) to inhaled carbachol in cats with very mild, chronic bronchitis (n = 5) that were ... [more ▼]

This study investigated the effect of inhaled fluticasone on lower airway inflammation and bronchial responsiveness (BR) to inhaled carbachol in cats with very mild, chronic bronchitis (n = 5) that were compared with healthy cats serving as controls (n = 6). Chest radiographs, BR tests performed non-invasively by barometric whole body plethysmography (BWBP) and bronchoalveolar lavage (BAL) were performed before and after treatment. BR was quantified by calculating the concentration of carbachol inducing bronchoconstriction (C-Penh300%), defined as a 300% increase of baseline Penh, an index of bronchoconstriction obtained by BWBP. BAL fluid was analyzed cytologically and the oxidant marker 8-iso-PGF2α was determined. At test 1, healthy cats and cats with bronchitis were untreated, whereas for test 2 inhalant fluticasone (250 μg once daily) was administrated for 2 consecutive weeks to cats with bronchitis. Control cats remained untreated. Inhaled fluticasone induced a significant increase in C-Penh300% and a significant decrease of BAL fluid total cells, macrophages, neutrophils and 8-iso-PGF2α in cats with bronchitis, whilst untreated control cats did not show significant changes over time. This study shows that a 2-week fluticasone treatment significantly reduced lower airway inflammation in very mild bronchitis. BR could be successfully monitored in cats using BWPB and decreased significantly in response to inhaled fluticasone. 8-Iso-PGF2α in BAL fluid was responsive to treatment and appeared as a sensitive biomarker of lower airway inflammation in cats. [less ▲]

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See detailEncapsulation of the sunscreen agent, octyl dimethyl PABA, in lipid microparticles: effect on photostability
Tursilli, Rosanna; Scalia, Santo; Piel, Géraldine ULg et al

Poster (2006)

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See detailEffect of ß-Cyclodextrin Derivatives on Bronchial Epithelial Cell Layer Permeability
Bosquillon, C; Belhadj Salem, L; Hernandez, E et al

in Delivery to the lung (2006), 17

Cyclodextrins have been identified as promising adjuvants for pulmonary drug delivery. However, concerns regarding possible adverse effects on the respiratory epithelium may limit their development in ... [more ▼]

Cyclodextrins have been identified as promising adjuvants for pulmonary drug delivery. However, concerns regarding possible adverse effects on the respiratory epithelium may limit their development in inhaled products. Concentrations (10-50 mM) of three ß-cyclodextrin derivatives, randomly methylated ß-cyclodextrin (RAMEB), hydroxypropyl-ß-cyclodextrin (HPßCD) and Kleptose® CRYSMEB, were applied to human respiratory epithelial (Calu-3) cell layers and effects on permeability were evaluated by 14C-mannitol permeability and transepithelial electrical resistance (TEER) measurements. Each cyclodextrin produced a concentration-dependent increase in mannitol flux which was associated with a drop in TEER. Increases in mannitol flux were the highest after exposure to RAMEB and were not apparent until a 50-60% reduction in TEER was reached. Disrupted cell layers recovered to their initial TEER value in less than 24 h except after exposure to high concentrations of RAMEB. Perturbations of the Calu-3 cell layers were shown to be dependent on cyclodextrin concentration, as well as chemical derivatisation, and were reversible in all but the most severe cases. [less ▲]

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See detailUse of the MTT assay to evaluate the biocompatibility of beta-cyclodextrin derivatives with respiratory epithelial cells
Patel, J.; Belhadj Salem; Martin, G. P. et al

in Journal of Pharmacy and Pharmacology (2006), 58(58), 64-65

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See detailEtude des performances d'appareils de melange Unguator pour la preparation magistrale a usage dermatologique
Stassen, T.; Piette, Marie ULg; Kinget, R. et al

in Journal de Pharmacie de Belgique (2006), 61(1), 1-10

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See detailMulti-biomaterial for controlled release of active substances
Zalfen, Alina; Nizet, Dominique; Jérôme, Christine ULg et al

Poster (2006)

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See detailEffect of cyclodextrins on the membrane permeability of liposomes
Piel, Géraldine ULg; Piette, Marie ULg; Barillaro, Valery et al

Poster (2005, November)

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See detailCyclodextrin-mediated drug release from liposomes dispersed within a bioadhesive gel
Piel, Géraldine ULg; Boulmedarat, Laila; Bochot, Amelie et al

in Pharmaceutical Research (2005), 22(6), 962-971

Purpose. The aim of the present study was to design a new mucosal drug delivery system composed of liposomes dispersed within a bioadhesive hydrogel containing methyl-beta-cyclodextrin (Me beta CD) for ... [more ▼]

Purpose. The aim of the present study was to design a new mucosal drug delivery system composed of liposomes dispersed within a bioadhesive hydrogel containing methyl-beta-cyclodextrin (Me beta CD) for controlled drug release. Methods. A hydrophilic model molecule, inulin, was encapsulated within positively charged and PEGylated liposomes and its release was measured in the presence of Me beta CD after vesicle dispersion within the bioadhesive Carbopol(R) 974P gel. Freeze-fracture electron microscopy (FFEM) was used to follow liposome morphological changes when dispersed within the hydrogel. Liposome- Me beta CD interactions were investigated by turbidity monitoring during continuous addition of Me beta CD to liposomes and by FFEM. Results. Inulin diffusion within the gel was influenced by Carbopol(R) 974P concentration since no gel erosion occurred. When dispersed within the gel, positively charged liposomes displayed a higher stability than PEG-ylated vesicles. In the presence of Me beta CD, higher amounts of free inulin were released from liposomes, especially in Carbopol(R)-free system. Me beta CD appeared to diffuse towards lipid vesicles and permeabilized their bilayer allowing inulin leakage. Indeed, freeze-fracture experiments and liposome turbidity monitoring have shown that Me beta CD behaved as a detergent behavior, resulting in lipid vesicle solubilization. Conclusion. Me beta CD is able to mediate, within a bioadhesive hydrogel, the release of a liposome-encapsulated molecule allowing further application of this delivery system for mucosal administration. [less ▲]

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See detailAutomated method for the determination of a new matrix metalloproteinase inhibitor in ovine plasma and serum by coupling of restricted access material for on-line sample clean-up to liquid chromatography
Chiap, Patrice ULg; Piette, Marie ULg; Evrard, Brigitte ULg et al

in Journal of Chromatography. B : Analytical Technologies in the Biomedical & Life Sciences (2005), 817(1), 109-117

A fully automated liquid chromatographic method was developed for the determination of Ro 28-2653, a new synthetic inhibitor of matrix metalloproteinases (MMPs), in ovine serum and plasma. The method was ... [more ▼]

A fully automated liquid chromatographic method was developed for the determination of Ro 28-2653, a new synthetic inhibitor of matrix metalloproteinases (MMPs), in ovine serum and plasma. The method was based on the coupling of a pre-column packed with restricted access material, namely LiChrospher RP-8 ADS (alkyl diol silica), for sample clean-up to an analytical column containing octyl silica stationary phase. One hundred mul of biological sample, to which 2-propanol was automatically added, were injected onto the ADS pre-column, which was then washed with a washing liquid consisting of a mixture of 25 mM phosphate buffer (pH 7.0) and acetonitrile (90: 10; v/v) for 10 min. By rotation of the switching valve, the analyte was then eluted in the back-flush mode with the LC mobile phase composed of a mixture of acetonitrile and 25 mM phosphate buffer (pH 7.0) (57:43; v/v). The UV detection was performed at 395 nm. The main parameters likely to influence the sample preparation technique were investigated. The method was then validated over a concentration range from 17.5 to 1950 ng/mI, the first concentration level corresponding to the lower limit of quantitation. At this concentration level, the mean bias and the R.S.D. value for intermediate precision were -2.4% and 4.2%, respectively. (C) 2004 Elsevier B.V. All rights reserved. [less ▲]

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