The Experts below are selected from a list of 18 Experts worldwide ranked by ideXlab platform
Jacques Crommen - One of the best experts on this subject based on the ideXlab platform.
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simultaneous determination of Methylphenobarbital enantiomers and phenobarbital in human plasma by on line coupling of an achiral precolumn to a chiral liquid chromatographic column
Journal of Chromatography A, 1998Co-Authors: Attilio Ceccato, Patrice Chiap, Bruno Boulanger, Philippe Hubert, Jacques CrommenAbstract:A fully automated liquid chromatographic (LC) method for the simultaneous determination of Methylphenobarbital enantiomers and phenobarbital in human plasma has been developed. The method is based on the use of a precolumn packed with an internal-surface reversed-phase packing material (LiChrospher ADS) for sample clean-up coupled to LC analysis on a cellulose tris(4-methylbenzoate) based chiral stationary phase (Chiralcel OJ-R). A 100-mu l plasma sample was injected directly on the precolumn packed with LiChrospher RP-18 ADS using a mixture of pH 5.0 phosphate buffer-methanal (97:3, v/v) as washing liquid. The analytes were then eluted in the back-flush mode with the LC mobile phase. The enantiomeric separation of Methylphenobarbital was achieved on Chiralcel OJ-R. The retention times were modelled using a D-optimal design with ten experimental points in order to optimise the LC mobile phase for the separation of phenobarbital from the enantiomers of mephobarbital. The factors selected were the acetonitrile content, the pH and the sodium perchlorate concentration in the mobile phase. A Derringer's desirability function was used to find an optimal and robust solution within the experimental domain. The mobile phase selected consisted of a mixture of pH 7.0 phosphate buffer-acetonitrile (60:40, v/v). The elution profiles of phenobarbital, Methylphenobarbital and blank plasma samples on the precolumn and the time needed for analyte transfer from the precolumn to the analytical column were then determined. Finally, the method developed was validated. (C) 1998 Elsevier Science B.V. All rights reserved.
Roberto A Olsina - One of the best experts on this subject based on the ideXlab platform.
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simultaneous spectrophotometric determination of phenobarbital phenytoin and Methylphenobarbital in pharmaceutical preparations by using partial least squares and principal component regression multivariate calibration
Journal of Pharmaceutical and Biomedical Analysis, 2000Co-Authors: M S Boeris, J M Luco, Roberto A OlsinaAbstract:Abstract Two multivariate calibration methods, partial least squares (PLS-2) and principal component regression (PCR) have been applied to the simultaneous spectrophotometric analysis of ternary mixtures of phenytoin (DPH), phenobarbital (PBT) and Methylphenobarbital (MPBT) in the Comital-L pharmaceutical formulation. The PLS-2 and PCR procedures were employed to evaluate the data of a variable number of calibration solutions measured over the wavelength range 400–700 nm. The concentration ranges used to construct the calibration matrix were varied between 5 and 30 μg ml−1. The proposed methods were validated by applying them to the analysis of the Comital-L pharmaceutical formulation and the average relative errors were less than 6% for each one of the analyzed compounds. The results obtained by both proposed methods have been compared with the results obtained by application of a RPLC reference method.
Attilio Ceccato - One of the best experts on this subject based on the ideXlab platform.
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simultaneous determination of Methylphenobarbital enantiomers and phenobarbital in human plasma by on line coupling of an achiral precolumn to a chiral liquid chromatographic column
Journal of Chromatography A, 1998Co-Authors: Attilio Ceccato, Patrice Chiap, Bruno Boulanger, Philippe Hubert, Jacques CrommenAbstract:A fully automated liquid chromatographic (LC) method for the simultaneous determination of Methylphenobarbital enantiomers and phenobarbital in human plasma has been developed. The method is based on the use of a precolumn packed with an internal-surface reversed-phase packing material (LiChrospher ADS) for sample clean-up coupled to LC analysis on a cellulose tris(4-methylbenzoate) based chiral stationary phase (Chiralcel OJ-R). A 100-mu l plasma sample was injected directly on the precolumn packed with LiChrospher RP-18 ADS using a mixture of pH 5.0 phosphate buffer-methanal (97:3, v/v) as washing liquid. The analytes were then eluted in the back-flush mode with the LC mobile phase. The enantiomeric separation of Methylphenobarbital was achieved on Chiralcel OJ-R. The retention times were modelled using a D-optimal design with ten experimental points in order to optimise the LC mobile phase for the separation of phenobarbital from the enantiomers of mephobarbital. The factors selected were the acetonitrile content, the pH and the sodium perchlorate concentration in the mobile phase. A Derringer's desirability function was used to find an optimal and robust solution within the experimental domain. The mobile phase selected consisted of a mixture of pH 7.0 phosphate buffer-acetonitrile (60:40, v/v). The elution profiles of phenobarbital, Methylphenobarbital and blank plasma samples on the precolumn and the time needed for analyte transfer from the precolumn to the analytical column were then determined. Finally, the method developed was validated. (C) 1998 Elsevier Science B.V. All rights reserved.
M S Boeris - One of the best experts on this subject based on the ideXlab platform.
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simultaneous spectrophotometric determination of phenobarbital phenytoin and Methylphenobarbital in pharmaceutical preparations by using partial least squares and principal component regression multivariate calibration
Journal of Pharmaceutical and Biomedical Analysis, 2000Co-Authors: M S Boeris, J M Luco, Roberto A OlsinaAbstract:Abstract Two multivariate calibration methods, partial least squares (PLS-2) and principal component regression (PCR) have been applied to the simultaneous spectrophotometric analysis of ternary mixtures of phenytoin (DPH), phenobarbital (PBT) and Methylphenobarbital (MPBT) in the Comital-L pharmaceutical formulation. The PLS-2 and PCR procedures were employed to evaluate the data of a variable number of calibration solutions measured over the wavelength range 400–700 nm. The concentration ranges used to construct the calibration matrix were varied between 5 and 30 μg ml−1. The proposed methods were validated by applying them to the analysis of the Comital-L pharmaceutical formulation and the average relative errors were less than 6% for each one of the analyzed compounds. The results obtained by both proposed methods have been compared with the results obtained by application of a RPLC reference method.
Bruno Boulanger - One of the best experts on this subject based on the ideXlab platform.
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simultaneous determination of Methylphenobarbital enantiomers and phenobarbital in human plasma by on line coupling of an achiral precolumn to a chiral liquid chromatographic column
Journal of Chromatography A, 1998Co-Authors: Attilio Ceccato, Patrice Chiap, Bruno Boulanger, Philippe Hubert, Jacques CrommenAbstract:A fully automated liquid chromatographic (LC) method for the simultaneous determination of Methylphenobarbital enantiomers and phenobarbital in human plasma has been developed. The method is based on the use of a precolumn packed with an internal-surface reversed-phase packing material (LiChrospher ADS) for sample clean-up coupled to LC analysis on a cellulose tris(4-methylbenzoate) based chiral stationary phase (Chiralcel OJ-R). A 100-mu l plasma sample was injected directly on the precolumn packed with LiChrospher RP-18 ADS using a mixture of pH 5.0 phosphate buffer-methanal (97:3, v/v) as washing liquid. The analytes were then eluted in the back-flush mode with the LC mobile phase. The enantiomeric separation of Methylphenobarbital was achieved on Chiralcel OJ-R. The retention times were modelled using a D-optimal design with ten experimental points in order to optimise the LC mobile phase for the separation of phenobarbital from the enantiomers of mephobarbital. The factors selected were the acetonitrile content, the pH and the sodium perchlorate concentration in the mobile phase. A Derringer's desirability function was used to find an optimal and robust solution within the experimental domain. The mobile phase selected consisted of a mixture of pH 7.0 phosphate buffer-acetonitrile (60:40, v/v). The elution profiles of phenobarbital, Methylphenobarbital and blank plasma samples on the precolumn and the time needed for analyte transfer from the precolumn to the analytical column were then determined. Finally, the method developed was validated. (C) 1998 Elsevier Science B.V. All rights reserved.