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Hong T.,Key Laboratory of Drug Quality Control and Pharmacovigilance | Zheng Y.,Key Laboratory of Drug Quality Control and Pharmacovigilance | Hu W.,Key Laboratory of Drug Quality Control and Pharmacovigilance | Ji Y.,China Pharmaceutical University
Analytical Biochemistry | Year: 2014

A system of capillary silica monolith with bovine serum albumin (BSA) functionalized through two approaches for affinity monolithic capillary electrochromatography (AMCEC) was developed. Covalent immobilization conditions for two different Schiff base methods, which employed 3-glycidopropyl trimethoxysilane (GPTS) and 3-aminopropyl trimethoxysilane (APTS) as starting materials, respectively, were investigated to obtain good and stable chiral separation. The BSA immobilized silica monoliths were evaluated in terms of morphology, electroosmotic flow, retention time, column efficiency and resolution of model compound (±)-tryptophan. The columns exhibited satisfactory run-to-run, column-to-column repeatability and maintained their enantioselectivity for more than 3 months. Both developed methods can baseline separate tryptophan enantiomers, whereas shorter retention time, better column efficiency, and enantiomeric recognition between two pairs of drug enantiomers (pantoprazole and atenolol) were obtained by the GPTS method. © 2014 Elsevier Inc. All rights reserved. Source

Fan X.-M.,Key Laboratory of Drug Quality Control and Pharmacovigilance | Fan X.-M.,China Pharmaceutical University | Ji Y.-B.,Key Laboratory of Drug Quality Control and Pharmacovigilance | Ji Y.-B.,China Pharmaceutical University | Zhu D.-N.,China Pharmaceutical University
Chromatographia | Year: 2010

An integrated strategy based on experimental designs for the development, optimization and validation of the fingerprint method of Sheng-Mai-San by MEKC has been described. Orthogonal and sequential uniform designs were employed to select important experimental parameters and optimize CE conditions. Method validation was performed in terms of injection precision, sample stability test and robustness testing. Additionally, conventional modeling method was used to predict the optimum separation conditions for comparative purpose. The strategy described can also be utilized for fingerprint development in the quality control of other herbal medicines. © 2010 Vieweg+Teubner Verlag | Springer Fachmedien Wiesbaden GmbH. Source

Liu Y.,Key Laboratory of Drug Quality Control and Pharmacovigilance | Liu Y.,China Pharmaceutical University | Chen L.,Key Laboratory of Drug Quality Control and Pharmacovigilance | Chen L.,China Pharmaceutical University | And 2 more authors.
Journal of Pharmaceutical and Biomedical Analysis | Year: 2013

Seven impurities in agomelatine drug substance were determined by a newly developed RP-HPLC method. Structures of potential impurities were confirmed by NMR and IR analysis. Efficient chromatographic separation was achieved on Hypersil BDS C18 column (250mm×4.6mm, 5μm) in gradient mode by using a binary mixture of potassium dihydrogen phosphate (15mM, pH adjusted to 3.0) and acetonitrile at a flow rate of 1.0ml/min. A photodiode array detector set at 230nm was used for detection. Forced degradation studies showed that the proposed method was specific, and agomelatine was found to be susceptible to acidic and alkaline conditions. The method was validated according to ICH guidelines with respect to specificity, sensitivity, precision, linearity, accuracy, robustness and system suitability. Detection limit of impurities was in the range of 0.0008-0.0047%. Regression analysis showed correlation coefficient value greater than 0.999 for agomelatine and its seven impurities. Accuracy of the method was established based on the recovery obtained between 94.4% and 106.7% for all impurities. The validation results demonstrated that the developed method was suitable for the quantitative determination of potential impurities in agomelatine. A possible mechanism for the formation of impurities was proposed. © 2013 Elsevier B.V. Source

Hong T.,China Pharmaceutical University | Hong T.,Key Laboratory of Drug Quality Control and Pharmacovigilance | Chi C.,China Pharmaceutical University | Chi C.,Key Laboratory of Drug Quality Control and Pharmacovigilance | And 2 more authors.
Journal of Separation Science | Year: 2014

Pepsin-modified affinity monolithic capillary electrochromatography, a novel microanalysis system, was developed by the covalent bonding of pepsin on silica monolith. The column was successfully applied in the chiral separation of (±)-nefopam. Furthermore, the electrochromatographic performance of the pepsin-functionalized monolith for enantiomeric analysis was evaluated in terms of protein content, pH of running buffer, sample volume, buffer concentration, applied voltage, and capillary temperature. The relative standard deviation (%RSD) values of retention time (intraday <0.53, n = 10; interday <0.53, n = 10; column-to-column <0.70, n = 20; and batch-to-batch <0.80, n = 20) indicated satisfactory stability of these columns. No appreciable change was observed in retention and resolution for chiral recognition of (±)-nefopam in 50 days with 100 injections. The proteolytic activity of this stationary phase was further characterized with bovine serum albumin as substrate for online protein digestion. As for monolithic immobilized enzyme reactor, successive protein injections confirmed both the operational stability and ability to reuse the bioreactor for at least 20 digestions. It implied that the affinity monolith used in this research opens a new path of exploring particularly versatile class of enzymes to develop enzyme-modified affinity capillary monolith for enantioseparation. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA. Source

Liu M.,Key Laboratory of Drug Quality Control and Pharmacovigilance | Liu M.,China Pharmaceutical University | Zheng Y.,Key Laboratory of Drug Quality Control and Pharmacovigilance | Zheng Y.,China Pharmaceutical University | And 3 more authors.
Journal of Pharmaceutical and Biomedical Analysis | Year: 2011

A selective capillary electrophoresis method for determination of enantiomeric purity of RS86017, a new antiarrhythmic agent with two chiral centers, was developed and validated using sulfobutyl ether-β-cyclodextrin as chiral selector. The concentration of the chiral selector and organic modifier, pH of background electrolyte (BGE), capillary temperature, and applied voltage were systematically optimized by using orthogonal design and concentration of chiral selector was further optimized. The optimal conditions included 25. mM phosphate buffer at pH 8.0, containing 28. mg/mL sulfobutyl ether-β-cyclodextrin and 20% acetonitrile as running buffer, an applied voltage of 22. kV, and a temperature of 20 °C. The detection wavelength was 206. nm. The obtained method was capable of separating RS86017 from its potential chiral impurities, the S,R-enantiomer, the R,R-diastereomer and the S,S-diastereomer with a short analysis time of 10. min. The separation was validated with respect to its selectivity, repeatability, linearity, precision, accuracy, limits of detection (LOD), limits of quantitation (LOQ) and robustness testing. The LODs and LOQs were 0.8 μg/mL and 2.5 μg/mL for all isomers of RS86017, respectively. Finally, the method was used to investigate the chiral purity of RS86017 in bulk samples. © 2011 Elsevier B.V. Source

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