Browsing
     by title


0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

or enter first few letters:   
OK
Peer Reviewed
See detailEnantiomeric separation of acidic and basic drugs by capillary electrophoresis using neutral and anionic cyclodextrins
Fillet, Marianne ULg; Bechet, I.; Schomburg, G. et al

in Journal de Pharmacie de Belgique (1996), 51

Detailed reference viewed: 5 (1 ULg)
Full Text
Peer Reviewed
See detailEnantiomeric separation of acidic compounds using single-isomer amino cyclodextrin derivatives in nonaqueous capillary electrophoresis
Fradi, Inès; Servais, Anne-Catherine ULg; Pedrini, Matteo et al

in Electrophoresis (2006), 27(17), 3434-3442

The enantiomeric separation of a series of acidic pharmaceuticals (mostly nonsteroidal anti-inflammatory drugs) has been investigated in NACE systems using single-isomer amino beta-CD derivatives. The ... [more ▼]

The enantiomeric separation of a series of acidic pharmaceuticals (mostly nonsteroidal anti-inflammatory drugs) has been investigated in NACE systems using single-isomer amino beta-CD derivatives. The first part of this study consisted of the selection of the basic experimental conditions to separate efficiently the enantiomers of acidic drugs. Several parameters, such as the nature of the ionic BGE components, were studied and a methanolic solution of ammonium acetate containing the cationic CD was selected as BGE. A D-optimal design with 20 experimental points was then applied and the nature and concentration of the CD were found to have a significant effect on the enantiomeric resolution for all studied compounds. Resolution (R(s)) values were always higher with 6-monodeoxy-6-mono(3-hydroxy)propylamino-beta-CD (PA-beta-CD) compared to those obtained with 6-monodeoxy-6-mono(2-hydroxy)propylamino-beta-CD (IPA-beta-CD). However, the latter led to shorter migration times. Generic NACE conditions were then selected by means of the multivariate approach in order to obtain the highest R(s) values in a minimum amount of time. Finally, dependence of separation selectivity, resolution, as well as mobility difference on chiral selector concentration was discussed and binding constants with PA-beta-CD were estimated for the two enantiomers of one of the model compounds, suprofen in these NACE systems. [less ▲]

Detailed reference viewed: 27 (5 ULg)
Full Text
Peer Reviewed
See detailEnantiomeric separation of amino acid derivatives by non-aqueous capillary electrophoresis using quinine and related compounds as chiral additives.
Piette, Véronique; Fillet, Marianne ULg; Lindner, W. et al

in Biomedical Chromatography : BMC (2000), 14(1), 19-21

Enantiomeric separation of amino acid derivatives by non-aqueous capillary electrophoresis using quinine and related compounds as chiral additives.

Detailed reference viewed: 15 (0 ULg)
Full Text
Peer Reviewed
See detailEnantiomeric separation of aminoglutethimide by capillary electrophoresis using native cyclodextrins in single and dual systems
Abushoffa, A. M.; Fillet, Marianne ULg; Marini Djang'Eing'A, Roland ULg et al

in Journal of Separation Science (2003), 26(6-7), 536-542

Aminoglutethimide (AGT) is one of the few examples of chiral drugs that can be enantioseparated by capillary electrophoresis using any of the three native cyclodextrins: alpha-, beta-, or gamma-CD. A ... [more ▼]

Aminoglutethimide (AGT) is one of the few examples of chiral drugs that can be enantioseparated by capillary electrophoresis using any of the three native cyclodextrins: alpha-, beta-, or gamma-CD. A complete resolution of the enantiomers of this compound in cationic form could be achieved with each of the three CDs, using a pH 3 phosphoric acid-triethanolamine buffer. Affinity constants for AGT enantiomers with the three native CDs were determined, confirming that the highest selectivity was given by gamma-CD while the strongest complexation was obtained with beta-CD. However, an opposite affinity pattern was observed with the latter. Selectivity was lower for AGT enantiomers in dual CD systems, compared to that obtained with a single selector at its optimal concentration, which confirms that dual systems are of more limited interest when the two selectors have a similar effect on the analyte mobility. These results are in good agreement with those predicted using recently developed mathematical models. [less ▲]

Detailed reference viewed: 16 (4 ULg)
Full Text
Peer Reviewed
See detailEnantiomeric separation of basic compounds usin heptakis(2,3-di-O-methyl-6-O-sulfo)-beta-cyclodextrin in combination with potassium camphorsulfonate in nonaqueous capillary electrophoresis: Optimization by means of an experimental design
Servais, Anne-Catherine ULg; Fillet, Marianne ULg; Chiap, Patrice ULg et al

in Electrophoresis (2004), 25(16), 2701-2710

The enantiomeric separation of a series of basic pharmaceuticals (beta-blockers, local anesthetics, sympathomimetics) has been investigated in nonaqueous capillary electrophoresis (NACE) systems using ... [more ▼]

The enantiomeric separation of a series of basic pharmaceuticals (beta-blockers, local anesthetics, sympathomimetics) has been investigated in nonaqueous capillary electrophoresis (NACE) systems using heptakis(2,3-di-O-methyl-6-O-sulfo)-beta-cyclodextrin (HDMS-P-CD) in combination with potassium camphorsulfonate (camphorSO(3)(-)). For this purpose, a face-centered central composite design with 11 experimental points was applied. The effect of the concentrations of HDMS-beta-CD and camphorSO(3)(-) on enantioresolution was statistically evaluated and depended largely on the considered analyte. The presence of camphorSO(3)(-) was found to be particularly useful for the enantioseparation of compounds with high affinity for the anionic CD. CamphorSO(3)(-) seems to act as a competitor, reducing the affinity for the CD, probably by ion-pair formation with these analytes. For compounds with lower affinity for HDMS-beta-CD, the combination of camphorSO(3)(-) and the CD appeared to have a favorable effect on enantioresolution only if the optimal CD concentration could be reached. On the other hand, for compounds characterized by a very low affinity for the anionic CD, the association of camphorSO(3)(-) and HDMS-beta-CD is always unfavorable. Finally, experimental conditions were selected by means of the multivariate approach in order to obtain the highest resolution (R-s) value for each studied compound. [less ▲]

Detailed reference viewed: 21 (6 ULg)
Peer Reviewed
See detailEnantiomeric separation of basic drugs by cyclodextrin modified capillary electrophoresis using poly(vinyl alcohol) coated fused silica capillaries
Fillet, Marianne ULg; Schomburg, G.; Bechet, I. et al

in Journal de Pharmacie de Belgique (1995), 50

Detailed reference viewed: 7 (2 ULg)
Peer Reviewed
See detailEnantiomeric separation of basic drugs on an ovomucoid column
Ceccato, Attilio ULg; Hubert, Philippe ULg; Bechet, I. et al

in Journal de Pharmacie de Belgique (1992), 47

Detailed reference viewed: 14 (1 ULg)
Full Text
Peer Reviewed
See detailEnantiomeric Separation of Clenbuterol by Transient Isotachophoresis-Capillary Zone Electrophoresis-Uv Detection New Optimization Technique for Transient Isotachophoresis
Toussaint, B.; Hubert, Philippe ULg; Tjaden, U. R. et al

in Journal of Chromatography. A (2000), 871(1-2), 173-80

A method for the in-line preconcentration and enantioseparation of clenbuterol by transient isotachophoresis-capillary zone electrophoresis-UV absorbance detection (transient ITP-CZE-UV) has been ... [more ▼]

A method for the in-line preconcentration and enantioseparation of clenbuterol by transient isotachophoresis-capillary zone electrophoresis-UV absorbance detection (transient ITP-CZE-UV) has been developed. It implies the use of dimethyl-beta-cyclodextrin as chiral selector and the application of a hydrodynamic counterflow during the ITP step. ITP is used to focus the sample constituents prior to CE whereas a counterpressure counterbalances the electrophoretic migration of the compounds. The sample is then focused and kept stationary in the proximity of the capillary inlet before CZE separation, leading to an extended-volume ITP-CZE system. A new strategy for the fast optimization of the counterpressure has been developed which implies the measurement of the hydrodynamic and electrophoretic velocities of the analyte during ITP. The in-line preconcentration and enantioseparation of clenbuterol selected as model compound was optimized using this method. Salbutamol was chosen as internal reference in order to check the reproducibility of the method. A 173-nl volume of aqueous ample solution was injected which implies an improvement of the injection volume of about 16 and a resolution of 4.8 was obtained for the clenbuterol enantiomers. A concentration detection limit of 10(-6) mol/l was readily achieved for clenbuterol and salbutamol using only 3 min ITP preconcentration in in-line counterflow transient ITP-CZE-UV. Thanks to its fast optimization, the method is applicable to any enantioseparation by means of only five very short preliminary measurements. [less ▲]

Detailed reference viewed: 19 (1 ULg)