References of "Delattre, Luc"
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See detailSolid lipid Nanoparticles for drug Pumonary Administration
Sanna, Vanna; Kirschvink, Nathalie; Gustin, Pascal ULg et al

in Proceedings of 30th International Symposium on Controlled Release of Bioactive Materials (2003)

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See detailFormulation of submicronic emulsions by using a high-pressure homogeniser
Roland, I; Evrard, Brigitte ULg; Erpicum, T et al

in Journal de Pharmacie de Belgique (2003), 57

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See detailOral bioavailability in sheep of albendazole from a suspension and from a solution containing hydroxypropyl-beta-cyclodextrin
Evrard, Brigitte ULg; Chiap, Patrice ULg; De Tullio, Pascal ULg et al

in Journal of Controlled Release (2002), 85(1-3), 45-50

Albendazole (ABZ) is a benzimidazole derivative with a broad spectrum of activity against human and animal helminthe parasites. ABZ has a very poor aqueous solubility. This study shows that hydroxypropyl ... [more ▼]

Albendazole (ABZ) is a benzimidazole derivative with a broad spectrum of activity against human and animal helminthe parasites. ABZ has a very poor aqueous solubility. This study shows that hydroxypropyl-beta-cyclodextrin (HP-beta-CD) is able to form inclusion complexes with ABZ and that is able to increase its aqueous solubility. A synergistic effect exists between HP-beta-CD and citric acid. The combination of HP-beta-CD (200 mM) and citric acid (50 mM) allows dissolution of more than 1.5 mg of ABZ per ml. The aim of this study is the in vivo evaluation in sheep of a solution of the inclusion complex of ABZ with HP-beta-CD in comparison with a suspension of the same drug. A significant (P<0.05) increase in the relative bioavailability is obtained with the solution containing the ABZ-HP-beta-CD complex as measured by ABZSO plasma levels. The area under the curve (AUC(0--> proportional, variant )) of the solution is 37% higher than that obtained with the suspension. Likewise the peak plasma concentration (C(max)) is twice that of the solution while the time to reach C(max) (T(max)) is reduced. [less ▲]

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See detailApplication of Supercritical carbon dioxide for the preparation of drug-cyclodextrin inclusion compounds
Van Hees, Thierry ULg; Barillaro, Valery; Piel, Géraldine ULg et al

in Journal of Inclusion Phenomena and Macrocyclic Chemistry (2002), 44(1-4), 271-274

Inclusion complexes of drugs into cyclodextrins (CDs) can be obtained at the solid state by means of supercritical dioxide (SCCO2). A successful inclusion with a yield >98.5% has been achieved with ... [more ▼]

Inclusion complexes of drugs into cyclodextrins (CDs) can be obtained at the solid state by means of supercritical dioxide (SCCO2). A successful inclusion with a yield >98.5% has been achieved with piroxicam and beta-CD. The temperature and the time of exposure to SCCO2 have a significant effect on the inclusion yield while the pressure has a negative effect. However, there is a strong interaction between temperature and pressure and this interaction has a positive influence. The molar ratio piroxicam-beta-CD and the addition of ternary alkaline agents were also found to be significant factors. The dissolution rate of the complexes formed using SCCO2 was found to be significantly higher than that of the physical mixture. Inclusion complexes have also been obtained with miconazole treating mixtures of miconazole, CDs and citric acid by SCCO2. This new technique of inclusion of poorly soluble drugs into CDs allows the preparation of solid complexes without using organic solvents and thus without residues. [less ▲]

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See detailDetermination of the free/included piroxicam ratio in cyclodextrin complexes: comparison between UV spectrophotometry and differential scanning calorimetry
Van Hees, Thierry ULg; Piel, Géraldine ULg; Henry de Hassonville, Sandrine et al

in European Journal of Pharmaceutical Sciences (2002), 15(4), 347-353

Few analytical techniques allow to evaluate the inclusion yield of cyclodextrin-drug complexes, because most manufacturing processes give amorphous products, In this study we have developed an alternative ... [more ▼]

Few analytical techniques allow to evaluate the inclusion yield of cyclodextrin-drug complexes, because most manufacturing processes give amorphous products, In this study we have developed an alternative method to differential scanning calorimetry, to accurately determine the free/complexed piroxicam ratio by UV spectroscopy. This method is based on the differential solubility of the piroxicam-beta-cyclodextrin 1:2.5 mol/mol complex in water-acetonitrile (1:1 v/v) (Solvent A) or in anhydrous acetonitrile (Solvent B). both containing 0.05 M HCl. In anhydrous acetonitrile, beta-cyclodextrin is insoluble and the included drug remains entrapped, allowing the free piroxicam determination, while with 50% of water, the complex is totally dissolved, allowing the determination of the total guest content. This method was validated for linearity, precision and accuracy. The presence of cyclodextrin does not influence the assays, but more than 0.5% of water in Solvent B significantly affects the determination of the free piroxicam content. In comparison with differential scanning calorimetry, both delectability and precision were improved. It is now possible to analyse complexes with an inclusion purity greater than 99%. (C) 2002 Elsevier Science B.V. All rights reserved. [less ▲]

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See detailAugmentation de la solubilité de l'acétate de cyprotérone par formation de complexes d'inclusion dans les cyclodextrines
Henry de Hassonville, Sandrine; Perly, Bruno; Piel, Géraldine ULg et al

Conference (2002, February)

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See detailInclusion Complexes of Cyproterone Acetate with Cyclodextrins in Aqueous Solution
Henry de Hassonville, Sandrine; Perly, Bruno; Piel, Géraldine ULg et al

in Journal of Inclusion Phenomena and Macrocyclic Chemistry (2002), 44

Cyproterone acetate (CPA) is a steroidal antiandrogen with a progestogenic activity. Given that this molecule has a very poor water solubility (2.1 μg/mL), different cyclodextrins (CDs) were tested to ... [more ▼]

Cyproterone acetate (CPA) is a steroidal antiandrogen with a progestogenic activity. Given that this molecule has a very poor water solubility (2.1 μg/mL), different cyclodextrins (CDs) were tested to form inclusion complexes and to increase solubility. Two different techniques were compared to study the affinity between CPA and CDs: phase-solubility studies and NMR spectroscopy. The stoichiometry and the stability constant could be determined for most complexes with the aid of phase-solubility studies. The greatest increase in solubility was achieved with the methylated β-CDs, but hydroxypropylated β- and γ -CDs also gave enhanced solubilities. 1H-NMR studies showed a solubility increase similar to that found with phase-solubility studies. The proof of inclusion in the 2,6-dimethyl-β-CD (DIMEB) was shown by 1H-NMR and t-ROESY spectra. [less ▲]

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See detailDevelopment and validation of a new Fourier transform infrared spectrometric method for the quantification of urea in creams and ointments
Otte, X; Evrard, Brigitte ULg; Delattre, Luc ULg et al

in Analytica Chimica Acta (2002), 451

A new Fourier transform infrared (FTIR) spectrometric method for the quantification of urea in creams and ointments was developed and validated. The sample was solubilized in a mixture of chloroform ... [more ▼]

A new Fourier transform infrared (FTIR) spectrometric method for the quantification of urea in creams and ointments was developed and validated. The sample was solubilized in a mixture of chloroform/acetonitrile (1/1 v/v) which allows to solubilize the vaseline or other fats as well as urea and water. The solution was examined in a transmission cell with a pathlength of 500 μm provided with NaCI windows. The urea spectrum was obtained by subtraction of the reference solvent mixture spectrum and the reference water spectrum from the sample spectrum. The absorbance of the peak at ±1688 cm-1 was compared to those of calibration standards to quantify urea. The detection limit and the quantification limit (three times and 10 times the noise, respectively) were estimated as 0.4 and 1.3 μg ml-1, respectively. Validation of the method was realized and application of this method to stability tests was done. [less ▲]

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See detailIn Vitro Comparison of the Antimycotic Activity of a Miconazole-Hp-Beta-Cyclodextrin Solution with a Miconazole Surfactant Solution
Piel, Géraldine ULg; Hayette, Marie-Pierre ULg; Pavoni, Ermanno et al

in Journal of Antimicrobial Chemotherapy (2001), 48(1), 83-7

The antimycotic activity of a new parenteral solution containing miconazole was compared with that of a marketed solution (Daktarin IV solution). This solution has been withdrawn from the Belgian market ... [more ▼]

The antimycotic activity of a new parenteral solution containing miconazole was compared with that of a marketed solution (Daktarin IV solution). This solution has been withdrawn from the Belgian market, probably because of toxic effects related to the presence of polyoxyl 35 castor oil. We propose a new formulation containing miconazole (10 mg/mL) (like the marketed solution), in combination with hydroxypropyl-beta-cyclodextrin and lactic acid. The MICs of these two solutions were determined by a broth microdilution method (based on NCCLS guidelines) for 67 yeasts and 50 filamentous fungi isolates. This study shows that the MICs obtained with these two solutions are not significantly different. [less ▲]

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See detailMolecular Modeling Study of Beta- and Gamma-Cyclodextrin Complexes with Miconazole
Piel, Géraldine ULg; Dive, Georges ULg; Evrard, Brigitte ULg et al

in European Journal of Pharmaceutical Sciences (2001), 13(3), 271-9

Different authors have demonstrated the inclusion of miconazole in cyclodextrins (CD). Miconazole can be included in the CD cavity both in the neutral and in the ionized form. The present study tries to ... [more ▼]

Different authors have demonstrated the inclusion of miconazole in cyclodextrins (CD). Miconazole can be included in the CD cavity both in the neutral and in the ionized form. The present study tries to understand which fragment of the miconazole molecule is involved in the inclusion. Austin Model 1 approximate molecular orbital calculations have been performed on several complexes between beta-cyclodextrin (betaCD) or gamma-cyclodextrin (gammaCD) and miconazole in the ionized and the non-ionized forms of the two R and S enantiomers in three different orientations. We observed that betaCD is a good vehicle to transport miconazole which can be very easily released. The complexation energy between miconazole and betaCD is not very high but the entropic factor has a great incidence on the stability of the formed complex. The inclusion of the dichlorobenzene-CH(2)-O- and of the imidazole part of the S isomer gives rise to the most probable complex in acidic conditions (ionized miconazole). Nevertheless, the inclusion should be considered as a dynamic process in which different parts of the molecule could be alternatively included in betaCD. The present work demonstrates the high capability of deformation of betaCD which could easily accommodate several types of ligand. By opposite, the cycle extension in gammaCD leads to a more rigid vehicle with regards to miconazole. [less ▲]

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See detailPreparation of poly(D,L-lactide) nanoparticles assisted by amphiphilic poly(methyl methacrylate-co-methacrylic acid) copolymers
Gautier, Sandrine; Grudzielski, Nathalie; Goffinet, Gerhard ULg et al

in Journal of Biomaterials Science. Polymer Edition (2001), 12(4), 429-450

When co-precipitated with amphiphilic copolymers from DMSO, poly(D,L-lactide) (PLA) can be readily converted into stable sub-200 nm nanoparticles by addition of an aqueous phase, free of any polymeric ... [more ▼]

When co-precipitated with amphiphilic copolymers from DMSO, poly(D,L-lactide) (PLA) can be readily converted into stable sub-200 nm nanoparticles by addition of an aqueous phase, free of any polymeric stabilizers such as poly(vinyl alcohol) or Poloxamer. In this work, the ability of random poly(methyl methacrylate-co-methacrylic acid) copolymers (PMMA-co-MA) to stabilize PLA nanoparticles was demonstrated, and the properties of PLA/PMMA-co-MA nanoparticles were investigated. When co-precipitated with PMMA-co-MA, PLA was totally converted into nanoparticles using a polymer concentration in DMSO (Cp) below 17.6 mg ml(-1), and a PMMA-co-MA proportion above a critical value depending on the content of MA repeating units (X). For instance, the lowest PMMA-co-MA proportion required was 0.9 mg mg(-1) PLA for X = 12%, and 0.5 mg mg(-1) PLA for X = 25% (for C(PLA) = 16 mg ml(-1) DMSO). The nanoparticle diameter was essentially independent of X, the proportion of PMMA-co-MA, and the PLA molecular weight, except for oligomers for which the nanoparticle diameter was smaller. It decreased when the organic phase was diluted (126 +/- 13 nm for Cp = 17.6 mg ml(-1), and 81 +/- 5 nm for C(P) = 5.6 mg ml(-1)). The time-dependence of the stability and the degradation of PLA/PMMA-co-MA nanoparticles was discussed. One of the main advantages of this technique is the ability to control surface properties and to bring functional groups to otherwise non-functionalized PLA nanoparticles. To illustrate this, a conjugate of PMMA-co-MA25 and biotin was synthesized, and used to prepare biotinylated nanoparticles that could be detected by fluorescence and transmission electron microscopy after infiltration into ligatured rat small intestine. [less ▲]

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See detailFormulation and characterisation of submicronic emulsions
Roland, Isabelle ULg; Evrard, Brigitte ULg; Erpicum, Thomas et al

Conference (2001)

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See detailFormulation of subcronic emulsions by using a high-pressure homogeniser
Roland, Isabelle ULg; Evrard, Brigitte ULg; Erpicum, Thomas et al

Conference (2001)

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See detailPreparation of mebendazole HP-beta-cyclodextrin complexes using water-soluble polymers and organic acids
Alvarez, Covadonga; Van Hees, Thierry ULg; Piel, Géraldine ULg et al

in STP Pharma Sciences (2001), 11(6), 439-442

Mebendazole (MBZ) is a carbamate derivative with an aminobenzimidazole structure. It possesses antihelminthic properties and is particularly insoluble in water. In order to increase its aqueous solubility ... [more ▼]

Mebendazole (MBZ) is a carbamate derivative with an aminobenzimidazole structure. It possesses antihelminthic properties and is particularly insoluble in water. In order to increase its aqueous solubility, hydroxpropyl-beta-cyclodextrin (HP-beta-CD) was used in combination with water-soluble polymers (polyvinylpyrrolidone or hydroxypropymethyl cellulose) and different organic acids (citric or tartaric). Increased solubility was observed on heating the mixture. The effects of the time and temperature of the heating process on drug solubility and stability were investigated. The results clearly show that the best conditions for increasing solubility and limiting degradation of MBZ is to heat a combination of MBZ, HP-beta-CD (200 mM), tartaric or citric acid (50 mM) and HPMC (0.1% w/v) in a water-bath at 95degreesC for 60 min. This method increases solubility to about 680 mug/ml and limits degradation to 2.5%. [less ▲]

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See detailPréparation de complexes mebendazole-HPβCD à l'aide de polymères solubles dans l'eau et d'acides organiques
Alvarez, C; Van Hees, Thierry ULg; Piel, Géraldine ULg et al

in Annales Pharmaceutiques Françaises (2001), 59

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