The Experts below are selected from a list of 172662 Experts worldwide ranked by ideXlab platform
Erwin Adams - One of the best experts on this subject based on the ideXlab platform.
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development and validation of a reversed phase liquid chromatographic method for analysis of griseofulvin and impurities
Journal of Pharmaceutical and Biomedical Analysis, 2013Co-Authors: Getu Kahsay, Aremu Olajire Adegoke, Ann Van Schepdael, Erwin AdamsAbstract:A simple and robust reversed phase liquid chromatographic method was developed and validated for the quantitative determination of griseofulvin (GF) and its impurities in drug substances and drug products (tablets). Chromatographic separation was achieved on a Discovery C18 (250mm×4.6mm, 5μm) column kept at 30°C. The mobile phase consisted of a gradient mixture of mobile phase A (water-0.1% formic acid pH 4.5, 80:20, v/v) and B (ACN-water-0.1% formic acid pH 4.5, 65:15:20, v/v/v) pumped at a flow rate of 1.0mL/min. UV detection was performed at 290nm. The method was validated for its Robustness, sensitivity, precision, accuracy and linearity based on ICH guidelines. The Robustness Study was performed by means of an experimental design and multivariate analysis. Satisfactory results were obtained from the validation studies. The use of volatile mobile phases allowed for the identification of three main impurities present above the identification threshold using mass spectrometry (MS). The developed LC method has been applied for the assay and impurity determination of GF drug substances and tablets. The method could be very useful for the quality control of GF and its impurities in bulk and formulated dosage forms.
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development of a liquid chromatography method for the analysis of josamycin
Journal of Pharmaceutical and Biomedical Analysis, 2008Co-Authors: F Daidone, R Heuvelmans, L Aerden, Jos Hoogmartens, Erwin AdamsAbstract:Abstract Out of three methods for the analysis of josamycin, the best one was selected and used as starting point for further development. A central composite design was applied to find the most influencing parameters and to optimize the chromatographic conditions and a full factorial design was used to perform a Robustness Study. The final method uses a Hypersil ODS column 5 μm, 250 mm × 4.6 mm i.d. maintained at 45 °C. The mobile phase is composed of acetonitrile–phosphate buffer (pH 3, 0.2 mol l −1 )–tetrabutylammonium hydrogen sulphate 0.2 mol l −1 –water (21:5:3:71, v/v/v/v). Strongly retained impurities after the main peak require gradient elution, which is obtained by increasing linearly the acetonitrile concentration (from 21% to 50%, v/v) and decreasing the TBA concentration (from 3% to 0%, v/v) in the mobile phase. The total run time was 65 min. UV detection is performed at 232 nm and the flow rate is 1 ml/min. The method shows good selectivity, precision, linearity and sensitivity. Five commercial bulk samples were analyzed.
Sagrario M Sanchez - One of the best experts on this subject based on the ideXlab platform.
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ad hoc blocked design for the Robustness Study in the determination of dichlobenil and 2 6 dichlorobenzamide in onions by programmed temperature vaporization gas chromatography mass spectrometry
Journal of Chromatography A, 2014Co-Authors: Ana Herrero, C. Reguera, Cruz M Ortiz, L A Sarabia, Sagrario M SanchezAbstract:Abstract An ‘ad-hoc’ experimental design to handle the Robustness Study for the simultaneous determination of dichlobenil and its main metabolite (2,6-dichlorobenzamide) in onions by programmed temperature vaporization-gas chromatography-mass spectrometry (PTV-GC-MS) is performed. Eighteen experimental factors were considered; 7 related with the extraction and clean up step, 8 with the PTV injection step and 3 factors related with the derivatization step. Therefore, a high number of experiments must be carried out that cannot be conducted in one experimental session and, as a consequence, the experiments of the Robustness Study must be performed in several sessions or blocks. The procedure to obtain an experimental design suitable for this task works by simultaneously minimizing the joint confidence region for the coefficient estimates and the correlation among them and with the block. In this way, the effect of the factors is not aliased with the block avoiding possible misinterpretations of the effects of the experimental factors on the analytical responses. The developed experimental design is coupled to the PARAFAC2 method, which allows solving some specific problems in chromatography when working with complex matrix such as co-elution of interferents (including silylation artifacts from the derivatization step) and small shifts in the retention time and, besides, the unequivocal identification of the target compounds according to document SANCO/12571/2013.
Ana Herrero - One of the best experts on this subject based on the ideXlab platform.
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ad hoc blocked design for the Robustness Study in the determination of dichlobenil and 2 6 dichlorobenzamide in onions by programmed temperature vaporization gas chromatography mass spectrometry
Journal of Chromatography A, 2014Co-Authors: Ana Herrero, C. Reguera, Cruz M Ortiz, L A Sarabia, Sagrario M SanchezAbstract:Abstract An ‘ad-hoc’ experimental design to handle the Robustness Study for the simultaneous determination of dichlobenil and its main metabolite (2,6-dichlorobenzamide) in onions by programmed temperature vaporization-gas chromatography-mass spectrometry (PTV-GC-MS) is performed. Eighteen experimental factors were considered; 7 related with the extraction and clean up step, 8 with the PTV injection step and 3 factors related with the derivatization step. Therefore, a high number of experiments must be carried out that cannot be conducted in one experimental session and, as a consequence, the experiments of the Robustness Study must be performed in several sessions or blocks. The procedure to obtain an experimental design suitable for this task works by simultaneously minimizing the joint confidence region for the coefficient estimates and the correlation among them and with the block. In this way, the effect of the factors is not aliased with the block avoiding possible misinterpretations of the effects of the experimental factors on the analytical responses. The developed experimental design is coupled to the PARAFAC2 method, which allows solving some specific problems in chromatography when working with complex matrix such as co-elution of interferents (including silylation artifacts from the derivatization step) and small shifts in the retention time and, besides, the unequivocal identification of the target compounds according to document SANCO/12571/2013.
C. Reguera - One of the best experts on this subject based on the ideXlab platform.
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ad hoc blocked design for the Robustness Study in the determination of dichlobenil and 2 6 dichlorobenzamide in onions by programmed temperature vaporization gas chromatography mass spectrometry
Journal of Chromatography A, 2014Co-Authors: Ana Herrero, C. Reguera, Cruz M Ortiz, L A Sarabia, Sagrario M SanchezAbstract:Abstract An ‘ad-hoc’ experimental design to handle the Robustness Study for the simultaneous determination of dichlobenil and its main metabolite (2,6-dichlorobenzamide) in onions by programmed temperature vaporization-gas chromatography-mass spectrometry (PTV-GC-MS) is performed. Eighteen experimental factors were considered; 7 related with the extraction and clean up step, 8 with the PTV injection step and 3 factors related with the derivatization step. Therefore, a high number of experiments must be carried out that cannot be conducted in one experimental session and, as a consequence, the experiments of the Robustness Study must be performed in several sessions or blocks. The procedure to obtain an experimental design suitable for this task works by simultaneously minimizing the joint confidence region for the coefficient estimates and the correlation among them and with the block. In this way, the effect of the factors is not aliased with the block avoiding possible misinterpretations of the effects of the experimental factors on the analytical responses. The developed experimental design is coupled to the PARAFAC2 method, which allows solving some specific problems in chromatography when working with complex matrix such as co-elution of interferents (including silylation artifacts from the derivatization step) and small shifts in the retention time and, besides, the unequivocal identification of the target compounds according to document SANCO/12571/2013.
Cruz M Ortiz - One of the best experts on this subject based on the ideXlab platform.
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ad hoc blocked design for the Robustness Study in the determination of dichlobenil and 2 6 dichlorobenzamide in onions by programmed temperature vaporization gas chromatography mass spectrometry
Journal of Chromatography A, 2014Co-Authors: Ana Herrero, C. Reguera, Cruz M Ortiz, L A Sarabia, Sagrario M SanchezAbstract:Abstract An ‘ad-hoc’ experimental design to handle the Robustness Study for the simultaneous determination of dichlobenil and its main metabolite (2,6-dichlorobenzamide) in onions by programmed temperature vaporization-gas chromatography-mass spectrometry (PTV-GC-MS) is performed. Eighteen experimental factors were considered; 7 related with the extraction and clean up step, 8 with the PTV injection step and 3 factors related with the derivatization step. Therefore, a high number of experiments must be carried out that cannot be conducted in one experimental session and, as a consequence, the experiments of the Robustness Study must be performed in several sessions or blocks. The procedure to obtain an experimental design suitable for this task works by simultaneously minimizing the joint confidence region for the coefficient estimates and the correlation among them and with the block. In this way, the effect of the factors is not aliased with the block avoiding possible misinterpretations of the effects of the experimental factors on the analytical responses. The developed experimental design is coupled to the PARAFAC2 method, which allows solving some specific problems in chromatography when working with complex matrix such as co-elution of interferents (including silylation artifacts from the derivatization step) and small shifts in the retention time and, besides, the unequivocal identification of the target compounds according to document SANCO/12571/2013.
