The Experts below are selected from a list of 55263 Experts worldwide ranked by ideXlab platform
Jaafar Al I Tamimi - One of the best experts on this subject based on the ideXlab platform.
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a selective and rapid method for the quantification of captopril in human plasma using liquid chromatography selected reaction monitoring mass spectrometry
Journal of Pharmaceutical and Biomedical Analysis, 2005Co-Authors: Isam I Salem, Weasm Abu Saif, Yazen Jmeian, Jaafar Al I TamimiAbstract:A specific hyphenated high performance liquid chromatography-mass spectrometric (LC-MS/MS) assay was developed for the Determination of captopril in plasma. The Drug was extracted from plasma using liquid-liquid extraction with a mixture of diethylether:dichloromethane. After the addition of the internal standard, samples were applied to a prepacked C8 Waters Symmetry column. The ion trap MS/MS detector was equipped with electrospray ionization (ESI) source operating in the positive ion mode. Drug Determination was accomplished monitoring captopril at molecular ion m/z 218 and MS/MS (daughter) at m/z 171.6. The method was applied to captopril Determination in human plasma after the administration of captopril 50 mg tablets to healthy volunteers who have participated in a pharmacokinetic study. The method was proved to be specific and precise by testing six different plasma batches. Linearity was established for the range of concentrations 25-3000 ng/ml with a regression factor of 0.9995. Intra-day accuracy ranged from 90.16 to 96.18%, while the intra-day precision ranged from 2.60 to 9.66% at the concentrations of 75, 1440 and 2500 ng/ml. Inter-day precision of the method ranged from 5.04 to 10.10%. This validated method of analysis was successfully applied to human plasma analyses after the administration of a single dose of 50 mg captopril tablets to healthy volunteers.
Yuanqing Xia - One of the best experts on this subject based on the ideXlab platform.
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the need for adequate chromatographic separation in the quantitative Determination of Drugs in biological samples by high performance liquid chromatography with tandem mass spectrometry
Rapid Communications in Mass Spectrometry, 1999Co-Authors: Mohammed Jemal, Yuanqing XiaAbstract:This work describes real examples of classes of Drugs (Drug candidates) whose quantitative Determination in biological matrices by high performance liquid chromatography with electrospray tandem mass spectrometry (LC/MS/MS) may be hampered by interferences from Drug-related biotransformation products (or proDrugs), unless the chromatographic conditions used achieve the separation of the Drug from Drug-related compounds. The classes of Drugs investigated include: (a) a lactone Drug, with the open-ring acid as the potential biotransformation product; (b) a phenolic Drug and its proDrug; (c) an E-isomer methyloxime Drug, with its Z-isomer as the potential biotransformation product; (d) a carboxylic acid Drug, with its acylglucuronide as the potential biotransformation product; and (e) a thiol Drug, with its disulfide as the potential biotransformation product. For each pair of a Drug and the associated compound (except for the isomeric pair), the full-scan electrospray single mass spectrum of the associated compound gave an in-source collisionally induced dissociation (CID) generated fragment ion identical to the parent ion of the Drug. Thus, the associated compound, if present in the biological sample, would interfere with the quantitative Determination of the Drug by LC/MS/MS using the selected reaction monitoring (SRM) transition of the parent ion of the Drug, unless the LC conditions utilized achieve clearcut separation of the Drug from the associated compound. Thus, LC/MS/MS bioanalytical methods with very short retention times, where there are minimal chromatographic separations, should be used only for biological samples which are known to not contain analyte-related compounds that can undergo the SRM transition used for the Drug Determination. Copyright © 1999 John Wiley & Sons, Ltd.
Isam I Salem - One of the best experts on this subject based on the ideXlab platform.
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a selective and rapid method for the quantification of captopril in human plasma using liquid chromatography selected reaction monitoring mass spectrometry
Journal of Pharmaceutical and Biomedical Analysis, 2005Co-Authors: Isam I Salem, Weasm Abu Saif, Yazen Jmeian, Jaafar Al I TamimiAbstract:A specific hyphenated high performance liquid chromatography-mass spectrometric (LC-MS/MS) assay was developed for the Determination of captopril in plasma. The Drug was extracted from plasma using liquid-liquid extraction with a mixture of diethylether:dichloromethane. After the addition of the internal standard, samples were applied to a prepacked C8 Waters Symmetry column. The ion trap MS/MS detector was equipped with electrospray ionization (ESI) source operating in the positive ion mode. Drug Determination was accomplished monitoring captopril at molecular ion m/z 218 and MS/MS (daughter) at m/z 171.6. The method was applied to captopril Determination in human plasma after the administration of captopril 50 mg tablets to healthy volunteers who have participated in a pharmacokinetic study. The method was proved to be specific and precise by testing six different plasma batches. Linearity was established for the range of concentrations 25-3000 ng/ml with a regression factor of 0.9995. Intra-day accuracy ranged from 90.16 to 96.18%, while the intra-day precision ranged from 2.60 to 9.66% at the concentrations of 75, 1440 and 2500 ng/ml. Inter-day precision of the method ranged from 5.04 to 10.10%. This validated method of analysis was successfully applied to human plasma analyses after the administration of a single dose of 50 mg captopril tablets to healthy volunteers.
Mohammed Jemal - One of the best experts on this subject based on the ideXlab platform.
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the need for adequate chromatographic separation in the quantitative Determination of Drugs in biological samples by high performance liquid chromatography with tandem mass spectrometry
Rapid Communications in Mass Spectrometry, 1999Co-Authors: Mohammed Jemal, Yuanqing XiaAbstract:This work describes real examples of classes of Drugs (Drug candidates) whose quantitative Determination in biological matrices by high performance liquid chromatography with electrospray tandem mass spectrometry (LC/MS/MS) may be hampered by interferences from Drug-related biotransformation products (or proDrugs), unless the chromatographic conditions used achieve the separation of the Drug from Drug-related compounds. The classes of Drugs investigated include: (a) a lactone Drug, with the open-ring acid as the potential biotransformation product; (b) a phenolic Drug and its proDrug; (c) an E-isomer methyloxime Drug, with its Z-isomer as the potential biotransformation product; (d) a carboxylic acid Drug, with its acylglucuronide as the potential biotransformation product; and (e) a thiol Drug, with its disulfide as the potential biotransformation product. For each pair of a Drug and the associated compound (except for the isomeric pair), the full-scan electrospray single mass spectrum of the associated compound gave an in-source collisionally induced dissociation (CID) generated fragment ion identical to the parent ion of the Drug. Thus, the associated compound, if present in the biological sample, would interfere with the quantitative Determination of the Drug by LC/MS/MS using the selected reaction monitoring (SRM) transition of the parent ion of the Drug, unless the LC conditions utilized achieve clearcut separation of the Drug from the associated compound. Thus, LC/MS/MS bioanalytical methods with very short retention times, where there are minimal chromatographic separations, should be used only for biological samples which are known to not contain analyte-related compounds that can undergo the SRM transition used for the Drug Determination. Copyright © 1999 John Wiley & Sons, Ltd.
Weasm Abu Saif - One of the best experts on this subject based on the ideXlab platform.
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a selective and rapid method for the quantification of captopril in human plasma using liquid chromatography selected reaction monitoring mass spectrometry
Journal of Pharmaceutical and Biomedical Analysis, 2005Co-Authors: Isam I Salem, Weasm Abu Saif, Yazen Jmeian, Jaafar Al I TamimiAbstract:A specific hyphenated high performance liquid chromatography-mass spectrometric (LC-MS/MS) assay was developed for the Determination of captopril in plasma. The Drug was extracted from plasma using liquid-liquid extraction with a mixture of diethylether:dichloromethane. After the addition of the internal standard, samples were applied to a prepacked C8 Waters Symmetry column. The ion trap MS/MS detector was equipped with electrospray ionization (ESI) source operating in the positive ion mode. Drug Determination was accomplished monitoring captopril at molecular ion m/z 218 and MS/MS (daughter) at m/z 171.6. The method was applied to captopril Determination in human plasma after the administration of captopril 50 mg tablets to healthy volunteers who have participated in a pharmacokinetic study. The method was proved to be specific and precise by testing six different plasma batches. Linearity was established for the range of concentrations 25-3000 ng/ml with a regression factor of 0.9995. Intra-day accuracy ranged from 90.16 to 96.18%, while the intra-day precision ranged from 2.60 to 9.66% at the concentrations of 75, 1440 and 2500 ng/ml. Inter-day precision of the method ranged from 5.04 to 10.10%. This validated method of analysis was successfully applied to human plasma analyses after the administration of a single dose of 50 mg captopril tablets to healthy volunteers.
