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Yvan Vander Heyden - One of the best experts on this subject based on the ideXlab platform.

  • chiral separations of cathinone and amphetamine derivatives comparative study between capillary electrochromatography supercritical fluid chromatography and three liquid chromatographic modes
    Journal of Pharmaceutical and Biomedical Analysis, 2016
    Co-Authors: Dima Albals, Yvan Vander Heyden, Martin G Schmid, Bezhan Chankvetadze, Debby Mangelings
    Abstract:

    Abstract The screening part of an earlier defined chiral separation strategy in capillary electrochromatography (CEC) was used for the separation of ten cathinone- and amphetamine derivatives. They were analyzed using 4 polysaccharide-based chiral stationary phases (CSPs), containing cellulose tris(3,5-dimethylphenylcarbamate) (ODRH), amylose tris(3,5-dimethylphenylcarbamate) (ADH), amylose tris(5-chloro-2-methylphenylcarbamate) (LA2), and cellulose tris(4-chloro-3-methylphenylcarbamate) (LC4) as chiral selectors. After applying the screening to each compound, ADH and LC4 showed the highest success rate. In a second part of the study, a comparison between CEC and other analytical techniques used for chiral separations i.e., supercritical fluid chromatography (SFC), Polar Organic Solvent chromatography (POSC), reversed-phase (RPLC) and normal-phase liquid chromatography (NPLC), was made. For this purpose, earlier defined screening approaches for each technique were applied to separate the 10 test substances. This allowed an overall comparison of the success rates of the screening steps of the 5 techniques for these compounds. The results showed that CEC had a similar enantioselectivity rate as NPLC and RPLC, producing the highest number of separations (9 out of 10 racemates). SFC resolved 7 compounds, while POSC gave only 2 separations. On the other hand, the baseline separation success rates for NPLC and RPLC was better than for CEC. For a second comparison, the same chiral stationary phases as in the CEC screening were also tested with all techniques at their specific screening conditions, which allowed a direct comparison of the performance of CEC versus the same CSPs in the other techniques. This comparison revealed that RPLC was able to separate all tested compounds, and also produced the highest number of baseline separations on the CSP that were used in the CEC screening step. CEC and NPLC showed the same success rate: nine out of ten substances were separated. When CEC and NPLC are combined, separation of the ten compounds can be achieved. SFC and POSC resolved eight and three compounds, respectively. POSC was the least attractive option as it expressed only limited enantioselectivity toward these compounds.

  • chiral separations in Polar Organic Solvent chromatography updating a screening strategy with new chlorine containing polysaccharide based selectors
    Journal of Chromatography B, 2008
    Co-Authors: Hasret Ates, Debby Mangelings, Yvan Vander Heyden
    Abstract:

    The screening conditions of an existing column and mobile phase selection strategy for chiral drug substances in Polar Organic Solvent liquid chromatography (POSC) were tested for their applicability on two new chlorine-containing polysaccharide-based stationary phases. The selectors of these phases are cellulose tris(3-chloro-4-methylphenylcarbamate) and amylose tris(5-chloro-2-methylphenylcarbamate). The enantioselectivity of these phases is compared to that of the four phases (Chiralpak® AD-RH, Chiralcel® OD-RH, Chiralpak® AS-RH and Chiralcel® OJ-RH) used in the earlier defined strategy. A test set of 62 structurally diverse chiral drug substances is analyzed using the screening conditions of the strategy on the six phases. The results confirm that the acetonitrile-based mobile phase provides a higher success rate and better resolutions than the methanol-based also on the new phases. However, the importance of the methanol-based mobile phase cannot be neglected for complementarity reasons; the two mobile phases insure enantioselectivity for different compounds. A third (ethanol-based) mobile phase, not part of the strategy, was also used to screen the two new phases. The joint results led to different possibilities to upgrade the current screening strategy so that improved success rates are obtained. The chlorine-containing chiral stationary phases demonstrated to have an added value to the screening process since they provided enantioresolution for compounds not resolved by non-chlorine-containing ones.

  • chiral separation strategy in Polar Organic Solvent chromatography and performance comparison with normal phase liquid and supercritical fluid chromatography
    IEEE Journal of Solid-state Circuits, 2006
    Co-Authors: N Matthijs, Mohamed Maftouh, Yvan Vander Heyden
    Abstract:

    A strategy, including a rapid screening and several optimisation steps, for the separation of chiral molecules of pharmaceutical interest by Polar Organic Solvent chromatography (POSC), using four polysaccharide-based stationary phases, is proposed and compared with previously reported strategies in normal-phase (NPLC) and supercritical fluid chromatography (SFC). In a first part of this paper, different examples demonstrate the effectiveness of the POSC strategy for fast method development. Optimisation is based on the use of experimental design to map the experimental domain in an efficient way. In the second part, the best screening results, obtained after performance of earlier defined chromatographic screening strategies in NPLC and SFC, are compared to those obtained in POSC. The three techniques show complementary separation results and allowed baseline separation of 23 of 25 compounds. POSC is found to be a very interesting separation mode compared to NPLC, because of the many fast (< 10 min) baseline separations obtained.

  • Screening approach for chiral separation of pharmaceuticals IV. Polar Organic Solvent chromatography.
    Journal of chromatography. A, 2006
    Co-Authors: N Matthijs, Mohamed Maftouh, Yvan Vander Heyden
    Abstract:

    The aim of this work is to determine generic screening conditions and an initial simple separation strategy allowing the rapid separation of drug enantiomers in Polar Organic Solvent chromatography (POSC). Four cellulose/amylose-based stationary phases were investigated in detail using two mobile phase basis Solvents commonly applied in this mode, i.e. acetonitrile and methanol. Polar mode is interesting for use in purification of enantiomers. In a first step, the parameters potentially influencing the separation, such as addition of an alcohol to the Polar Organic Solvent or the type of mobile phase additive(s), were examined by means of experimental designs. Afterwards, the factors found most important are investigated in more detail. Results showed that the cellulose- and amylose-based stationary phases have very broad and complementary enantiorecognition abilities in the POSC mode. The type of Organic Solvent for the mobile phase appeared to have a dramatic influence on the quality of the separation. Based on the results, a screening strategy was proposed. Enantioseparation was observed in more than 85% of the tested compounds and analysis times of last eluted peak were usually below 10 min.

  • Chiral separation strategy in Polar Organic Solvent chromatography and performance comparison with normal‐phase liquid and supercritical‐fluid chromatography
    Journal of separation science, 2006
    Co-Authors: N Matthijs, Mohamed Maftouh, Yvan Vander Heyden
    Abstract:

    A strategy, including a rapid screening and several optimisation steps, for the separation of chiral molecules of pharmaceutical interest by Polar Organic Solvent chromatography (POSC), using four polysaccharide-based stationary phases, is proposed and compared with previously reported strategies in normal-phase (NPLC) and supercritical fluid chromatography (SFC). In a first part of this paper, different examples demonstrate the effectiveness of the POSC strategy for fast method development. Optimisation is based on the use of experimental design to map the experimental domain in an efficient way. In the second part, the best screening results, obtained after performance of earlier defined chromatographic screening strategies in NPLC and SFC, are compared to those obtained in POSC. The three techniques show complementary separation results and allowed baseline separation of 23 of 25 compounds. POSC is found to be a very interesting separation mode compared to NPLC, because of the many fast (< 10 min) baseline separations obtained.

N Matthijs - One of the best experts on this subject based on the ideXlab platform.

  • chiral separation strategy in Polar Organic Solvent chromatography and performance comparison with normal phase liquid and supercritical fluid chromatography
    IEEE Journal of Solid-state Circuits, 2006
    Co-Authors: N Matthijs, Mohamed Maftouh, Yvan Vander Heyden
    Abstract:

    A strategy, including a rapid screening and several optimisation steps, for the separation of chiral molecules of pharmaceutical interest by Polar Organic Solvent chromatography (POSC), using four polysaccharide-based stationary phases, is proposed and compared with previously reported strategies in normal-phase (NPLC) and supercritical fluid chromatography (SFC). In a first part of this paper, different examples demonstrate the effectiveness of the POSC strategy for fast method development. Optimisation is based on the use of experimental design to map the experimental domain in an efficient way. In the second part, the best screening results, obtained after performance of earlier defined chromatographic screening strategies in NPLC and SFC, are compared to those obtained in POSC. The three techniques show complementary separation results and allowed baseline separation of 23 of 25 compounds. POSC is found to be a very interesting separation mode compared to NPLC, because of the many fast (< 10 min) baseline separations obtained.

  • Screening approach for chiral separation of pharmaceuticals IV. Polar Organic Solvent chromatography.
    Journal of chromatography. A, 2006
    Co-Authors: N Matthijs, Mohamed Maftouh, Yvan Vander Heyden
    Abstract:

    The aim of this work is to determine generic screening conditions and an initial simple separation strategy allowing the rapid separation of drug enantiomers in Polar Organic Solvent chromatography (POSC). Four cellulose/amylose-based stationary phases were investigated in detail using two mobile phase basis Solvents commonly applied in this mode, i.e. acetonitrile and methanol. Polar mode is interesting for use in purification of enantiomers. In a first step, the parameters potentially influencing the separation, such as addition of an alcohol to the Polar Organic Solvent or the type of mobile phase additive(s), were examined by means of experimental designs. Afterwards, the factors found most important are investigated in more detail. Results showed that the cellulose- and amylose-based stationary phases have very broad and complementary enantiorecognition abilities in the POSC mode. The type of Organic Solvent for the mobile phase appeared to have a dramatic influence on the quality of the separation. Based on the results, a screening strategy was proposed. Enantioseparation was observed in more than 85% of the tested compounds and analysis times of last eluted peak were usually below 10 min.

  • Chiral separation strategy in Polar Organic Solvent chromatography and performance comparison with normal‐phase liquid and supercritical‐fluid chromatography
    Journal of separation science, 2006
    Co-Authors: N Matthijs, Mohamed Maftouh, Yvan Vander Heyden
    Abstract:

    A strategy, including a rapid screening and several optimisation steps, for the separation of chiral molecules of pharmaceutical interest by Polar Organic Solvent chromatography (POSC), using four polysaccharide-based stationary phases, is proposed and compared with previously reported strategies in normal-phase (NPLC) and supercritical fluid chromatography (SFC). In a first part of this paper, different examples demonstrate the effectiveness of the POSC strategy for fast method development. Optimisation is based on the use of experimental design to map the experimental domain in an efficient way. In the second part, the best screening results, obtained after performance of earlier defined chromatographic screening strategies in NPLC and SFC, are compared to those obtained in POSC. The three techniques show complementary separation results and allowed baseline separation of 23 of 25 compounds. POSC is found to be a very interesting separation mode compared to NPLC, because of the many fast (< 10 min) baseline separations obtained.

Ajmal Koya Pulikkal - One of the best experts on this subject based on the ideXlab platform.

Mohamed Maftouh - One of the best experts on this subject based on the ideXlab platform.

  • chiral separation strategy in Polar Organic Solvent chromatography and performance comparison with normal phase liquid and supercritical fluid chromatography
    IEEE Journal of Solid-state Circuits, 2006
    Co-Authors: N Matthijs, Mohamed Maftouh, Yvan Vander Heyden
    Abstract:

    A strategy, including a rapid screening and several optimisation steps, for the separation of chiral molecules of pharmaceutical interest by Polar Organic Solvent chromatography (POSC), using four polysaccharide-based stationary phases, is proposed and compared with previously reported strategies in normal-phase (NPLC) and supercritical fluid chromatography (SFC). In a first part of this paper, different examples demonstrate the effectiveness of the POSC strategy for fast method development. Optimisation is based on the use of experimental design to map the experimental domain in an efficient way. In the second part, the best screening results, obtained after performance of earlier defined chromatographic screening strategies in NPLC and SFC, are compared to those obtained in POSC. The three techniques show complementary separation results and allowed baseline separation of 23 of 25 compounds. POSC is found to be a very interesting separation mode compared to NPLC, because of the many fast (< 10 min) baseline separations obtained.

  • Screening approach for chiral separation of pharmaceuticals IV. Polar Organic Solvent chromatography.
    Journal of chromatography. A, 2006
    Co-Authors: N Matthijs, Mohamed Maftouh, Yvan Vander Heyden
    Abstract:

    The aim of this work is to determine generic screening conditions and an initial simple separation strategy allowing the rapid separation of drug enantiomers in Polar Organic Solvent chromatography (POSC). Four cellulose/amylose-based stationary phases were investigated in detail using two mobile phase basis Solvents commonly applied in this mode, i.e. acetonitrile and methanol. Polar mode is interesting for use in purification of enantiomers. In a first step, the parameters potentially influencing the separation, such as addition of an alcohol to the Polar Organic Solvent or the type of mobile phase additive(s), were examined by means of experimental designs. Afterwards, the factors found most important are investigated in more detail. Results showed that the cellulose- and amylose-based stationary phases have very broad and complementary enantiorecognition abilities in the POSC mode. The type of Organic Solvent for the mobile phase appeared to have a dramatic influence on the quality of the separation. Based on the results, a screening strategy was proposed. Enantioseparation was observed in more than 85% of the tested compounds and analysis times of last eluted peak were usually below 10 min.

  • Chiral separation strategy in Polar Organic Solvent chromatography and performance comparison with normal‐phase liquid and supercritical‐fluid chromatography
    Journal of separation science, 2006
    Co-Authors: N Matthijs, Mohamed Maftouh, Yvan Vander Heyden
    Abstract:

    A strategy, including a rapid screening and several optimisation steps, for the separation of chiral molecules of pharmaceutical interest by Polar Organic Solvent chromatography (POSC), using four polysaccharide-based stationary phases, is proposed and compared with previously reported strategies in normal-phase (NPLC) and supercritical fluid chromatography (SFC). In a first part of this paper, different examples demonstrate the effectiveness of the POSC strategy for fast method development. Optimisation is based on the use of experimental design to map the experimental domain in an efficient way. In the second part, the best screening results, obtained after performance of earlier defined chromatographic screening strategies in NPLC and SFC, are compared to those obtained in POSC. The three techniques show complementary separation results and allowed baseline separation of 23 of 25 compounds. POSC is found to be a very interesting separation mode compared to NPLC, because of the many fast (< 10 min) baseline separations obtained.

Jianfeng Cai - One of the best experts on this subject based on the ideXlab platform.

  • enantiomeric analysis of simendan on polysaccharide based stationary phases by Polar Organic Solvent chromatography
    IEEE Journal of Solid-state Circuits, 2020
    Co-Authors: Lingping Cheng, Jianfeng Cai
    Abstract:

    Herein, the enantiomeric separation of simendan by high-performance liquid chromatography with ultraviolet detection using polysaccharide-based chiral stationary phases in Polar Organic mode is described. Three chiral columns (Chiralpak AD-H, Chiralcel OD-H, and Chiralpak AS) were screened using pure methanol and acetonitrile without additives under isocratic conditions. A reversed elution order was observed on the Chiralpak AD-H column when the methanol content in the mobile phase (methanol-acetonitrile mixtures) was above 10%, whereby levosimendan eluted prior to dextrosimendan. Further, it was found that increasing temperature effectively improved the enantioresolution on the Chiralpak AD-H column. Van't Hoff analysis was performed to evaluate the contribution of enthalpy and entropy to the chiral discrimination process. The best enantioseparation (α = 3.00, Rs = 12.85) was obtained on the Chiralpak AD-H column with methanol as the mobile phase at 40°C. Thus, a quantitative method for the resolution of dextrosimendan was established and validated, which could be used as a reference for the determination of dextrosimendan in levosimendan products.

  • Efficient preparative separation of 6-(4-aminophenyl)-5-methyl-4, 5-dihydro-3(2H)-pyridazinone enantiomers on polysaccharide-based stationary phases in Polar Organic Solvent chromatography and supercritical fluid chromatography.
    Journal of separation science, 2019
    Co-Authors: Lingping Cheng, Jianfeng Cai
    Abstract:

    6-(4-Aminophenyl)-5-methyl-4,5-dihydro-3(2H)-pyridazinone is a key synthetic intermediate for cardiotonic agent levosimendan. Very few studies address the use of chiral stationary phases in chromatography for the enantioseparation of this intermediate. This study presents two efficient preparative methods for the isolation of (R)(-)-6-(4-aminophenyl)-5-methyl-4,5-dihydro-3(2H)-pyridazinone in Polar Organic Solvent chromatography and supercritical fluid chromatography using polysaccharide-based chiral stationary phases and volatile Organic mobile phases without additives in isocratic mode. Under optimum conditions, Chiralcel OJ column showed the best performance (α = 1.71, Rs = 5.47) in Polar Organic Solvent chromatography, while Chiralpak AS column exhibited remarkable separations (α = 1.81 and Rs = 6.51) in supercritical fluid chromatography with an opposite enantiomer elution order. Considering the sample solubility, runtime and Solvent cost, the preparations were carried out on Chiralcel OJ column and Chiralpak AS column (250 × 20 mm i.d.; 10 µm) in Polar Organic mode and supercritical fluid chromatography mode with methanol and CO2 /methanol as mobile phases, respectively. By utilizing the advantages of chromatographic techniques and polysaccharide-based chiral stationary phases, this work provides two methods for the fast and economic preparation of (R)(-)-6-(4-aminophenyl)-5-methyl-4,5-dihydro-3(2H)-pyridazinone, which are suitable for the pharmaceutical industry.