References of "Piel, Géraldine"
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See detailStudy of the relationship between lipid binding properties of cyclodextrins and their effect on the integrity of liposomes
Piel, Géraldine ULg; Piette, Marie ULg; Barillaro, Valery et al

in International Journal of Pharmaceutics (2007), 338(1-2), 35-42

It is well known that cyclodextrins are able to extract lipids constituting membranes, increasing their fluidity and permeability. This behaviour towards biological membranes is directly linked to the ... [more ▼]

It is well known that cyclodextrins are able to extract lipids constituting membranes, increasing their fluidity and permeability. This behaviour towards biological membranes is directly linked to the toxicological effects of methylated cyclodextrins. However, confusion is currently made in the literature between the different methylated cyclodextrin derivatives. Moreover, a new methylated cyclodextrin derivative recently occurred in the market. the Crysmeb (R). We wanted to compare and understand the effect of the most currently used cyclodextrins on a model membrane. We studied the influence of natural cyclodextrins (beta CD and gamma CD), methylated derivatives (2,6-dimethyl-beta CD (Dimeb), 2,3,6-trimethyl-beta CD (Trimeb) and randomly methylated-beta CD (Rameb), as well as the new derivative Crysmeb), hydroxypropylated derivatives (HP beta CD of different substitution degrees and HP gamma CD) and the sulfobutylated derivative (SBE beta CD) on the release of a fluorescent marker encapsulated in the inner cavity of liposomes. It was shown that the observed effect on calcein release can be directly related to the affinity of cyclodextrins for both lipid components of liposomes, cholesterol and phosphatidylcholine. From this relationship, we were able to determine, for each cyclodextrin, a theoretical concentration giving rise to 50% or 100% calcein release. This theoretical concentration was confirmed experimentally. We have also showed that cyclodextrins which provoke calcein release also induce large structure modifications of liposomes. (c) 2007 Elsevier B.V. All rights reserved. [less ▲]

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See detailSolid lipid microparticles containing the sunscreen agent, octyl-dimethylaminobenzoate: Effect of the vehicle
Tursilli, Rosanna; Piel, Géraldine ULg; Delattre, Luc ULg et al

in European Journal of Pharmaceutics & Biopharmaceutics (2007), 66(3), 483-487

Solid lipid microparticles (SLMs) loaded with the sunscreen agent, octyl-dimethyl amino benzoate (ODAB), were prepared in order to achieve enhanced sunscreen photostability. The microparticles were ... [more ▼]

Solid lipid microparticles (SLMs) loaded with the sunscreen agent, octyl-dimethyl amino benzoate (ODAB), were prepared in order to achieve enhanced sunscreen photostability. The microparticles were produced by the melt dispersion technique using glyceryl behenate as lipidic material and poloxamer 188 as the emulsifier. The obtained SLMs showed proper features in terms of morphology, size distribution (1.67-15.81 mu m) and ODAB loading (16.15 +/- 0.11%, w/w). The sunscreen release from the SLMs was slower than its dissolution rate and the photodecomposition of ODAB was markedly decreased (> 51.3%) by encapsulation into the lipid microparticles. The efficacy of the SLM carrier system was also evaluated after their introduction in model topical formulations (i.e., hydrogel and oil-in-water emulsion). Further in vitro release measurements, performed using Franz diffusion cells with polycarbonate membranes, indicated that the retention capacity of the microparticles was lost after their incorporation into the emulsion, whereas it was retained in the hydrogel. Moreover, the SLMs achieved a reduction of the sunscreen photodegradation in the hydrogel vehicle (the ODAB loss decreased from 87.4% to 59.1%), whereas no significant photoprotective effect was observed in the emulsion. Therefore, the efficacy of the ODAB-loaded SLMs was markedly affected by the vehicle. (c) 2007 Elsevier B.V. All rights reserved. [less ▲]

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See detailStudy of the interaction between cyclodextrins and liposome membranes: effect on the permeability of liposomes
Piel, Géraldine ULg; Piette, Marie ULg; Barillaro, Valery et al

in Journal of Inclusion Phenomena and Macrocyclic Chemistry (2007, April), 57(1-4), 309-311

We wanted to compare and understand the effect of the most currently used cyclodextrins on a model membrane. We studied the influence of most currently used cyclodextrins on the release of a fluorescent ... [more ▼]

We wanted to compare and understand the effect of the most currently used cyclodextrins on a model membrane. We studied the influence of most currently used cyclodextrins on the release of a fluorescent marker encapsulated in the inner cavity of SUV liposomes. It was shown that the observed effect on calcein release can be directly related to the affinity of cyclodextrins for both lipid components of liposomes, cholesterol and phosphatidylcholine. From this relationship, we were able to determine, for each cyclodextrin, a theoretical concentration giving rise to 50% or 100% calcein release. This theoretical concentration was confirmed experimentally. [less ▲]

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See detailEvaluation of the cytotoxicity of cyclodextrins on endothelial cells using MTT assay
Castagne, Delphine ULg; Belhadj Salem, Leila; Delattre, Luc ULg et al

Poster (2007, April)

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See detailPreparation and evaluation of liposomes encapsulating synthetic MMP inhibitor (Ro 28-2653) - cyclodextrin complexes
Piette, Marie ULg; Castagne, Delphine ULg; Delattre, Luc ULg et al

in Journal of Inclusion Phenomena and Macrocyclic Chemistry (2007, April), 57(1-4), 101-103

In this study, preparation and evaluation of liposomes, intended for intravenous administration, encapsulating synthetic MMP inhibitor (Ro 28-2653) - cyclodextrin complexes were realized. An increase in ... [more ▼]

In this study, preparation and evaluation of liposomes, intended for intravenous administration, encapsulating synthetic MMP inhibitor (Ro 28-2653) - cyclodextrin complexes were realized. An increase in Ro solubility, via formation of binary (Ro/HP beta CD) or ternary (Ro/HP beta CD/L-lysine) complexes, permitted a similar increase in encapsulation efficiency of liposomes (Table 1). Moreover, Ro release kinetics depend on the encapsulation efficiency. [less ▲]

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See detailSolid lipid microparticles as a sustained release system for pulmonary drug delivery
Jaspart, Séverine ULg; Bertholet, Pascal; Piel, Géraldine ULg et al

in European Journal of Pharmaceutics & Biopharmaceutics (2007), 65(1), 47-56

The controlled release of drugs for pulmonary, delivery is a research field which has been so far rather unexploited but is currently becoming increasingly attractive. The introduction part of this ... [more ▼]

The controlled release of drugs for pulmonary, delivery is a research field which has been so far rather unexploited but is currently becoming increasingly attractive. The introduction part of this research article first details the potential advantages of solid lipid microparticles (SLMs) as drug carrier compared to liposomes and polymeric microspheres. The aim of this work is to use SLMs to impart a sustained release profile to a model drug, salbutamol acetonide (SA). SA was synthesized from salbutamol in order to increase the lipophilicity of this molecule and thereby to increase its incorporation efficiency into SLMs. SA-loaded SLMs were then produced by a hot emulsion technique followed by high-shear homogenisation and the manufacturing parameters were optimized using the experimental design methodology in order to reach a suitable particle size for pulmonary administration. Scanning electron micrographs showed that SLMs are spherical, have a smooth surface and that SA crystallises outside of the particles when the drug loading is higher than 20%. This was confirmed by X-ray diffraction. SA in vitro release study from SLMs showed that the release rate increased with SA loading but remained in every case lower than the dissolution rate of pure SA. (c) 2006 Elsevier B.V. All rights reserved. [less ▲]

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See detailContribution of cyclodextrins in the developement of different pharmaceutical formulations of a nex matrix metalloproteinase inhibitor
Evrard, Brigitte ULg; Bertholet, Pascal; Guéders, Maud ULg et al

in Journal of Inclusion Phenomena and Molecular Recognition in Chemistry (2007), 57(1-4), 303-308

Ro 28-2653 is a new synthetic inhibitor of matrix metalloproteinases. The ability of these enzymes to degrade various components of the extracellular matrix seems to play a major role in tumors ... [more ▼]

Ro 28-2653 is a new synthetic inhibitor of matrix metalloproteinases. The ability of these enzymes to degrade various components of the extracellular matrix seems to play a major role in tumors progression and is potentially effective against bronchial remodeling in asthma and BPCO. Ro 28-2653 is very poorly soluble in water. This low solubility estimated at about 0.56 lg/ml in water at 25 C gives rise to difficulties in pharmaceutical formulation of oral, injectable or <br />nebulizable solutions. The purpose of our study is to prepare and to characterize inclusion complexes between Ro 28-2653 and cyclodextrins and to investigate the biopharmaceutical repercussion of the inclusion of the active substance.The complex formation was investigated by phase solubility studies. 1H-NMR spectroscopy and molecular modeling studies were carried out to elucidate the structure of the inclusion <br />complex between Ro 28-2653 and cyclodextrin. Oral, intravenous and nebulizable solutions of Ro 28-2653 were developed with cyclodextrin. The in vivo studies were performed on healthy sheep for the pharmacokinetic evaluation of the oral and intravenous formulations while the nebulization of the complex solution was studied by using an asthma model in mouse. [less ▲]

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See detailSupercritical fluid technology to produce solid lipid microparticles
Nizet, Dominique; Jaspart, Séverine ULg; Brion, Michael et al

Conference (2007)

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See detailEffect of cyclodextrins on the viability of endothelial cells
Castagne, Delphine ULg; Belhadj Salem, Leila; Delattre, Luc ULg et al

in Journal of Inclusion Phenomena and Macrocyclic Chemistry (2007), 57(1-4), 105-107

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See detailDEVELOPMENT OF AN INTRAPERITONEAL IMPLANT FOR THE ENDOMETRIOSIS TREATMENT
Krier, Fabrice ULg; Nizet, Dominique; Riva, Raphaël ULg et al

Conference (2007)

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See detailOptimization of drug-cyclodextrin complexation reaction by a static supercritical carbon dioxide method
Brion, Michael; Nizet, Dominique; Piel, Géraldine ULg et al

Conference (2007)

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See detailTheoretical and experimental investigations on miconazole/cyclodextrin/acid complexes: Molecular modeling studies
Barillaro, Valéry; Dive, Georges ULg; Bertholet, Pascal et al

in International Journal of Pharmaceutics (2007), 342(1-2), 152-160

The inclusion of miconazole into cyclodextrin cavity has been demonstrated by different authors. Preliminary studies have shown which fragment of the molecule is involved in the inclusion. In the present ... [more ▼]

The inclusion of miconazole into cyclodextrin cavity has been demonstrated by different authors. Preliminary studies have shown which fragment of the molecule is involved in the inclusion. In the present study, AM1 approximate molecular orbital calculations have been performed on several cyclodextrins complexes ( CD, HP CD and HP CD) with miconazole and acidic compounds (maleic, fumaric and L-tartaric acids) as partners. For all the binary complexes, the inclusion of the dichlorobenzene–CH2–O-group leads to the most stable complex. For the ternary complexes, depending on their conformation and/or their structures, the acids can either stabilize or destabilize the complex. All the theoretical results were in good agreement with experimental data of miconazole inclusion yields into cyclodextrins. This work clearly demonstrates that the structure of both cyclodextrin and acid plays a key-role in the formation of inclusion complexes. [less ▲]

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