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Yaman ME, Kocak OF, Atila A, Kadioglu Y, Diyarbakir B, Halici Z. Rapid and sensitive UPLC-MS/MS method for the determination of etodolac in small-volume rat plasma: Application to rat real samples. J LIQ CHROMATOGR R T 2018. [DOI: 10.1080/10826076.2018.1464474] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Mehmet Emrah Yaman
- Department of Analytical Chemistry, Ataturk University Faculty of Pharmacy, Erzurum, Turkey
| | - Omer Faruk Kocak
- Department of Analytical Chemistry, Ataturk University Faculty of Pharmacy, Erzurum, Turkey
| | - Alptug Atila
- Department of Analytical Chemistry, Ataturk University Faculty of Pharmacy, Erzurum, Turkey
| | - Yucel Kadioglu
- Department of Analytical Chemistry, Ataturk University Faculty of Pharmacy, Erzurum, Turkey
| | - Busra Diyarbakir
- Department of Pharmacology, Ataturk University Faculty of Medicine, Erzurum, Turkey
| | - Zekai Halici
- Department of Pharmacology, Ataturk University Faculty of Medicine, Erzurum, Turkey
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2
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Investigation of a Quantitative Method for the Analysis of Chiral Monoterpenes in White Wine by HS-SPME-MDGC-MS of Different Wine Matrices. Molecules 2015; 20:7359-78. [PMID: 25911965 PMCID: PMC6272460 DOI: 10.3390/molecules20047359] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Revised: 04/16/2015] [Accepted: 04/16/2015] [Indexed: 11/16/2022] Open
Abstract
A valid quantitative method for the analysis of chiral monoterpenes in white wine using head-space solid phase micro-extraction-MDGC-MS (HS-SPME-MDGC-MS) with stable isotope dilution analysis was established. Fifteen compounds: (S)-(−)-limonene, (R)-(+)-limonene, (+)-(2R,4S)-cis-rose oxide, (−)-(2S,4R)-cis-rose oxide, (−)-(2R,4R)-trans-rose oxide, (+)-(2S,4S)-cis-rose oxide, furanoid (+)-trans-linalool oxide, furanoid (−)-cis-linalool oxide, furanoid (−)-trans-linalool oxide, furanoid (+)-cis-linalool oxide, (−)-linalool, (+)-linalool, (−)-α-terpineol, (+)-α-terpineol and (R)-(+)-β-citronellol were quantified. Two calibration curves were plotted for different wine bases, with varying residual sugar content, and three calibration curves for each wine base were investigated during a single fiber’s lifetime. This was needed as both sugar content and fiber life impacted the quantification of the chiral terpenes. The chiral monoterpene content of six Pinot Gris wines and six Riesling wines was then analyzed using the verified method. ANOVA with Tukey multiple comparisons showed significant differences for each of the detected chiral compounds in all 12 wines. PCA score plots showed a clear separation between the Riesling and Pinot Gris wines. Riesling wines had greater number of chiral terpenes in comparison to Pinot Gris wines. Beyond total terpene content it is possible that the differences in chiral terpene content may be driving the aromatic differences in white wines.
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3
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Hewala II, Moneeb MS, Elmongy HA, Wahbi AAM. Enantioselective HPLC-DAD method for the determination of etodolac enantiomers in tablets, human plasma and application to comparative pharmacokinetic study of both enantiomers after a single oral dose to twelve healthy volunteers. Talanta 2014; 130:506-17. [DOI: 10.1016/j.talanta.2014.07.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2014] [Revised: 06/02/2014] [Accepted: 07/06/2014] [Indexed: 10/25/2022]
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4
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Weiß JA, Mohr S, Schmid MG. Indirect Chiral Separation of New Recreational Drugs by Gas Chromatography-Mass Spectrometry Using Trifluoroacetyl-L-Prolyl Chloride as Chiral Derivatization Reagent. Chirality 2014; 27:211-5. [DOI: 10.1002/chir.22414] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 10/10/2014] [Indexed: 01/21/2023]
Affiliation(s)
- Jennifer A. Weiß
- Department of Pharmaceutical Chemistry, Institute of Pharmaceutical Sciences; Karl-Franzens University Graz; Graz Austria
| | - Stefan Mohr
- Research Center Pharmaceutical Engineering; Graz Austria
| | - Martin G. Schmid
- Department of Pharmaceutical Chemistry, Institute of Pharmaceutical Sciences; Karl-Franzens University Graz; Graz Austria
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5
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Srinivas NR. Role of Stereoselective Assays in Bioequivalence Studies of Racemic Drugs: Have We Reached a Consensus? J Clin Pharmacol 2013; 44:115-9. [PMID: 14747419 DOI: 10.1177/0091270003262098] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The existence of stereoselectivity in metabolism and drug disposition, coupled with the existence of genetic polymorphisms and modulation of enantiomeric kinetics via special delivery systems, provides some compulsion to assess bioequivalence using stereoselective data. However, examination of the literature suggests that nonstereoselective data are commonly used for the bioequivalence assessment of drug racemates.
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Affiliation(s)
- Nuggehally R Srinivas
- Dr. Reddy's Research Laboratories-Discovery Research, Bollaram Road, Miyapur, Hyderabad, India
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6
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Přech J, Matoušek V, Václavík J, Pecháček J, Syslová K, Šot P, Januščák J, Vilhanová B, Kuzma M, Kačer P. Determination of Enantiomeric Composition of Substituted Tetrahydroisoquinolines Based on Derivatization with Menthyl Chloroformate. ACTA ACUST UNITED AC 2013. [DOI: 10.4236/ajac.2013.43017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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7
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Mohr S, Weiß JA, Spreitz J, Schmid MG. Chiral separation of new cathinone- and amphetamine-related designer drugs by gas chromatography–mass spectrometry using trifluoroacetyl-l-prolyl chloride as chiral derivatization reagent. J Chromatogr A 2012; 1269:352-9. [DOI: 10.1016/j.chroma.2012.09.079] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Revised: 09/20/2012] [Accepted: 09/21/2012] [Indexed: 10/27/2022]
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8
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Hashim NH, Shafie S, Khan SJ. Enantiomeric fraction as an indicator of pharmaceutical biotransformation during wastewater treatment and in the environment--a review. ENVIRONMENTAL TECHNOLOGY 2010; 31:1349-1370. [PMID: 21121459 DOI: 10.1080/09593331003728022] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Enantioselective analysis of some pharmaceuticals during wastewater treatment has the potential to reveal significant insights regarding the effectiveness of biotransformation processes. Furthermore, enantioselective analysis of chiral pharmaceuticals in the aquatic environment may provide a useful historical record revealing the dominant source of (treated or untreated) wastewater contamination. This review of the recent scientific literature has identified only a handful of studies that have directly investigated these promising applications. However, a range of enantioselective analytical techniques are likely to be adaptable from those which have been developed within the pharmaceutical industry. These include direct enantioseparations of enantiomers on chiral stationary phases as well as indirect separations by achiral stationary phases after chiral derivatization to form pairs of physically distinguishable diastereomers. Further investigations of the patterns of enantiomeric fractionation of pharmaceuticals in wastewater and environmental samples will provide an increasingly solid understanding of the relationship between biotransformation processes and the often overlooked parameter of enantiomeric fraction.
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Affiliation(s)
- N H Hashim
- School of Civil and Environmental Engineering, University of New South Wales, Sydney, Australia
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9
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Gouda AA, Hassan WS. Spectrophotometric determination of etodolac in pure form and pharmaceutical formulations. Chem Cent J 2008; 2:7. [PMID: 18410679 PMCID: PMC2346468 DOI: 10.1186/1752-153x-2-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2007] [Accepted: 04/14/2008] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Etodolac (ETD) is a non-steroidal anti-inflamatory antirheumatic drug. A survey of the literature reveals that there is no method available for the determination of ETD in pure form and pharmaceutical formulations by oxidation-reduction reactions. RESULTS We describe three simple, sensitive and reproducible spectrophotometric assays (A-C) for the determination of etodolac in pure form and in pharmaceutical formulations. Methods A and B are based on the oxidation of etodolac by Fe3+ in the presence of o-phenanthroline (o-phen) or bipyridyl (bipy). The formation of the tris-complex on reaction with Fe3+-o-phen and/or Fe3+-bipy mixtures in acetate buffer solution at optimum pH was demonstrated at 510 and 520 nm with o-phen and bipy. Method C is based on the oxidation of etodolac by Fe3+ in acidic medium, and the subsequent interaction of iron(II) with ferricyanide to form Prussian blue, with the product exhibiting an absorption maximum at 726 nm. The concentration ranges are 0.5-8, 1.0-10 and 2-18 microg mL(-1) respectively for methods A, B and C. For more accurate analysis, Ringbom optimum concentration ranges were calculated, in addition to molar absorptivity, Sandell sensitivity, detection and quantification limits. CONCLUSION Our methods were successfully applied to the determination of etodolac in bulk and pharmaceutical formulations without any interference from common excipients. The relative standard deviations were
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Affiliation(s)
- Ayman A Gouda
- Chemistry Department, Faculty of Science, Zagazig University, Zagazig, Egypt
| | - Wafaa S Hassan
- Department of analytical Chemistry, Faculty of Pharmacy, Zagazig University, Zagazig, Egypt
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10
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Dogrukol-Ak D, Kutluk ÖB, Tunçel M, Aboul-Enein HY. CAPILLARY ELECTROPHORETIC METHOD FOR THE DETERMINATION OF ETODOLAC IN PHARMACEUTICAL TABLET FORMULATION. J LIQ CHROMATOGR R T 2007. [DOI: 10.1081/jlc-100103409] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
| | | | - Muzaffer Tunçel
- a University of Anadolu , 26470, Tepebaşi, Eskişehir, Turkey
| | - Hassan Y. Aboul-Enein
- b King Faisal Specialist Hospital and Research Centre , P.O. Box 3354, Riyadh, 11211, Saudi Arabia
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11
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Affiliation(s)
- Lingfeng He
- a Advanced Separation Technologies, Inc. , Whippany, New Jersey, USA
| | - Thomas E. Beesley
- a Advanced Separation Technologies, Inc. , Whippany, New Jersey, USA
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12
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Gübitz G, Schmid MG. Chiral separation principles in chromatographic and electromigration techniques. Mol Biotechnol 2006; 32:159-80. [PMID: 16444017 DOI: 10.1385/mb:32:2:159] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Almost half of the drugs in use today are chiral. It is well established that the pharmacological activity is mostly restricted to one of the enantiomers (eutomer). There can be qualitative and quantitative differences in the activity of the enantiomers. In many cases, the inactive enantiomer (distomer) shows unwanted side effects or even toxic effects. Even if the side effects are not that drastic, the distomer has to be metabolized and this represents an unnecessary burden for the organism. Therefore, the development of methods for the separation of enantiomers, both on analytical and preparative scale, has become increasingly important. Chromatographic techniques such as thin layer chromatography (TLC), gas chromatography (GC), supercritical fluid chromatography (SFC), and above all high-performance liquid chromatography (HPLC) have been used for enantiomer separation for about two decades. More recently, electromigration techniques, such as capillary electrophoresis and capillary electrochromatography, have been shown to be powerful alternatives to chromatographic methods. This review gives a short overview of different chiral separation principles and their application. Several new developments are discussed.
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Affiliation(s)
- Gerald Gübitz
- Institute of Pharmaceutical Sciences, Department of Pharmaceutical Chemistry, Karl-Franzens University, Universitätsplatz 1, A-8010 Graz, Austria
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13
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Paik MJ, Nguyen DT, Kim KR. N-Menthoxycarbonylation combined with trimethylsilylation for enantioseparation of β-blockers by achiral dual-column gas chromatography. J Chromatogr A 2006; 1103:177-81. [PMID: 16360666 DOI: 10.1016/j.chroma.2005.11.078] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2005] [Revised: 11/08/2005] [Accepted: 11/23/2005] [Indexed: 11/19/2022]
Abstract
Solvent extractive two-phase menthoxycarbonyl (MnOC) derivatization was combined with trimethylsilyl (TMS) reaction for enantioseparation of beta-blockers by gas chromatography employing achiral DB-5 and DB-17 dual-columns of different polarity. beta-Blockers in alkaline solution were vortex-mixed with menthyl chloroformate present in dichloromethane to be extracted as diastereomeric N-MnOC derivatives. The subsequent O(N)-TMS reaction allowed complete enantioseparations of two beta-blockers and partial separations of five as N-MnOC/O(N)-TMS derivatives in a single analysis. The temperature-programmed retention index sets were characteristic of each derivative, facilitating chiral discrimination of each enantiomer.
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Affiliation(s)
- Man-Jeong Paik
- Biometabolite Analysis Laboratory, College of Pharmacy, Sungkyunkwan University, Suwon 440-746, South Korea
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14
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Srinivas NR. Simultaneous chiral analyses of multiple analytes: case studies, implications and method development considerations. Biomed Chromatogr 2004; 18:759-84. [PMID: 15584016 DOI: 10.1002/bmc.447] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The field of chiral separations had a modest beginning some two decades ago. However, due to rapid technological advancement coupled with simultaneous availability of innovative chiral stationary phases and novel chiral derivatization agents, the field of chiral separations has now totally outpaced many other separation fields. Keeping pace with rapid changes in the field of chiral separations, investigators continue to add stereoselective pharmacokinetic, pharmacodynamic, pharmacologic and toxicological data of new and/or marketed racemic compounds to the literature. Examination of the evolution of chiral separations suggests that in the beginning many investigators attempted to separate and quantify a single pair of enantiomers, adopting either direct (separation made on a chiral stationary phase) or indirect (separation made following precolumn conversion of enantiomers to corresponding diastereomers) approaches. However, more recent trends in chiral separations suggest that investigators are attempting to separate and quantify multiple pairs of enantiomers with available technologies. Added to this, some interesting trends have been observed in many of the recently reported chiral applications, including preferences regarding internal standard selection, mobile phase contents and composition, sorting out issues with mass spectrometric detection, determination of elution order, analytical manipulations of metabolite(s) without reference standards and addressing some specificity-related issues. This review mainly focuses on chiral separations involving multiple chiral analytes and attempts to justify the need for such chiral separations involving multiple analytes. In this context, several cases studies are described on the utility and applicability of such chiral separations under discrete headings to provide an account to the readership on the implications of such tasks. The topics of case studies covered in this review include: (a) therapy markers--differentiation from drug abuse and/or applicability in forensics; (b) role in pharmacogenetic/polymorphic evaluation; (c) monitoring and understanding the role of parent and active metabolite(s) in clinical and preclinical investigations; (d) exploration on the pharmacokinetic utility of an active chiral metabolite vis-a-vis the racemic parent moiety; (e) understanding the chirality play in delineating peculiar toxic effects; (f) exploration of chiral inversion phenomenon, and understanding the role of stereoselective metabolism. For the further benefit of readership, some select examples (n = 19) of the separation of multiple chiral analytes with appropriate information on chromatography, detection system, validation parameters and applicable conclusion are also provided. Finally, the review covers some useful considerations for method development involving multiple chiral analytes.
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Affiliation(s)
- Nuggehally R Srinivas
- Drug Development, Discovery Research, Dr Reddy's Laboratories, Bollaram Road, Miyapur, Hyderabad 500 049, India.
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15
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Gübitz G, Schmid MG. Chiral separation by chromatographic and electromigration techniques. A review. Biopharm Drug Dispos 2001; 22:291-336. [PMID: 11835252 DOI: 10.1002/bdd.279] [Citation(s) in RCA: 194] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This review gives a survey of different chiral separation principles and their use in high-performance liquid chromatography (HPLC), gas chromatography (GC), supercritical fluid chromatography (SFC), thin-layer chromatography (TLC), capillary electrophoresis (CE) and capillary electrochromatography (CEC) highlighting new developments and innovative techniques. The mechanisms of the different separation principles are briefly discussed and some selected applications are shown.
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Affiliation(s)
- G Gübitz
- Institute of Pharmaceutical Chemistry and Pharmaceutical Technology, Karl-Franzens University, Universitätsplatz 1, A-8010 Graz, Austria.
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16
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Ki KR, Lee J, Ha D, Kim JH. Configurational analysis of chiral acids as O-trifluoroacetylated (-)-menthyl esters by achiral dual-capillary column gas chromatography. J Chromatogr A 2000; 891:257-66. [PMID: 11043786 DOI: 10.1016/s0021-9673(00)00690-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The simultaneous enantiomeric separation of 30 racemic acids including 24 hydroxy acids in a single analysis is described for the determination of their absolute configurations. It involves the conversion of each enantiomer into diastereomeric O-trifluoroacetylated (-)-menthyl ester for the direct separation by gas chromatography on achiral dual-capillary columns of different polarities, with subsequent identification and chiral discrimination by retention index (I) library matching. Among the acids studied, the enantiomers of 27 acids were discriminatively resolved on both non-polar DB-5 and the intermediate-polar DB-17 columns with resolution factors in the range of 0.7-7.7 and separation factors in the range of 1.002-1.021. Enantiomers of 3-hydroxybutyric and alpha-methoxyphenylacetic acids were partially resolved on DB-5 (resolution factor of 0.9), but not resolved on DB-17, while the baseline resolution for 3-hydroxydecanoic acid and the minimal separation on the peak top (resolution factor less than 0.7) for 2-hydroxyglutaric acid were achieved on DB-17 but not on DB-5. The temperature-programmed I values measured on both columns were characteristic of each enantiomer and thus simple I matching with the reference values was useful in cross-checking for their chemical identification and the chiral discrimination as well. When applied to a clinical urine sample, the present method allowed positive identification of endogenous (S)-lactic acid and (S)-2-hydroxybutyric acid along with (R)-3-hydroxybutyric acid.
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Affiliation(s)
- K R Ki
- College of Pharmacy, Sungkyunkwan University, Suwon, South Korea.
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17
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Kim KR, Lee J, Ha D, Jeon J, Park HG, Kim JH. Enantiomeric separation and discrimination of 2-hydroxy acids as O-trifluoroacetylated (S)-(+)-3-methyl-2-butyl esters by achiral dual-capillary column gas chromatography. J Chromatogr A 2000; 874:91-100. [PMID: 10768503 DOI: 10.1016/s0021-9673(00)00072-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
An efficient method is described for the simultaneous enantiomeric separation of 18 different racemic 2-hydroxy acids for the determination of their absolute configurations. It involves the conversion of each enantiomer into a diastereomeric O-trifluoroacetylated (S)-(+)-3-methyl-2-butyl ester for the direct separation by achiral dual-capillary column gas chromatography with subsequent identification and determination of its chirality by retention index (I) library matching. The enantiomers of each acid were well separated with high resolution values (R > or = 1.4) on DB-5 and DB-17 columns of different polarity. When temperature-programmed I values of 2-hydroxy acid enantiomers as their diastereomeric derivatives were measured on both columns, the I values were characteristic of each enantiomer. Simple I matching with the reference values was thus useful in cross-checking each acid enantiomer for the identification and chiral discrimination. When applied to urine samples, the present method allowed positive identification of most of the spiked 2-hydroxy acids from normal urine and for endogenous (S)-lactic acid and (S)-2-hydroxybutyric acid from a clinical urine specimen.
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Affiliation(s)
- K R Kim
- College of Pharmacy, Sungkyunkwan University, Suwon, South Korea.
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18
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Abstract
1. Many drugs used to treat psychiatric disorders contain a chiral center or a center of unsaturation and are marketed as a mixture of the resultant enantiomers or geometric isomers, respectively. These enantiomers or geometric isomers may differ markedly with regard to their pharmacodynamic and/or pharmacokinetic properties. 2. Examples of the effects of chiral centers or geometric centers on such properties are given for drugs from the following classes: antidepressants (tricyclics, selective serotonin reuptake inhibitors, monoamine oxidase inhibitors, viloxazine, bupropion, trazodone, mianserin, venlaflaxine); benzodiazepines, zoplicone, and antipsychotics. 3. As described in this review, there are several notable examples of psychiatric drugs currently available where the individual enantiomers or geometric isomers differ considerably with regard to factors such as effects on amine transport systems, interactions with receptors and metabolizing enzymes, and clearance rates from the body. Indeed, relatively recent developments in analytical and preparative resolution of racemic and geometric drug mixtures and increased interest in developing new drugs which interact with specific targets, which have been described in detail at the molecular level, have resulted in increased emphasis on stereochemistry in drug development.
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Affiliation(s)
- R M Lane
- Pfizer Inc., New York, New York 10017-5755, USA
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19
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El Kousy NM. Spectrophotometric and spectrofluorimetric determination of etodolac and aceclofenac. J Pharm Biomed Anal 1999; 20:185-94. [PMID: 10704022 DOI: 10.1016/s0731-7085(99)00019-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Two simple, sensitive and reproducible spectrophotometric and spectrofluorimetric methods were adopted for the analysis of the anti-inflammatory drugs, etodolac and aceclofenac. The first method is based on the formation of coloured complexes between the drugs and p-dimethylaminobenzaldehyde reagent (PDAB) in the presence of sulfuric acid and ferric chloride. Measurement of the absorbances was carried out at 591.5 and 545.5 nm for etodolac and aceclofenac, respectively. Regression analysis of Beer's plots showed good correlation in the concentration ranges 10-80 and 8-55 microg ml(-1), respectively. The second was the spectrofluorimetric method in which samples of etodolac in ethanol showed native fluorescence at a lambda = 345 nm when excitation was at 235 nm and samples of aceclofenac in the phosphate buffer pH 8 showed native fluorescence at lambda = 355 nm when excitation was at 250 nm. The calibration graph was rectilinear from 96 to 640 ng ml(-1) for etodolac and from 2 to 8 microg ml(-1) for aceclofenac. The proposed methods are applied successfully for the determination of the two drugs in bulk powder with a mean accuracy of 100.48+/-0.85 and 100.03+/-0.38 in the PDAB method and of 100.61+/-0.79 and 99.88+/-0.45 in the spectrofluorimetric method. Applicability of the proposed methods was examined by analysing dosage forms of the investigated drugs. Recoveries were 98.77-101.46 and 98.65-102.10% for the two methods, respectively and RSD values were 0.6-0.7 and 0.35-1.06% respectively.
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Affiliation(s)
- N M El Kousy
- National Organization for Drug Control and Research, Cairo, Egypt
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20
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Zeng S, Mao HQ. Stereoselective determination of fenfluramine enantiomers in rat liver microsomal incubates. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 1999; 727:107-12. [PMID: 10360428 DOI: 10.1016/s0378-4347(99)00044-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
An enantioselective assay for l- and d-fenfluramine in rat liver microsomal incubates was developed. The method involves extraction of fenfluramine from the microsomal incubates, and formation of fenfluramine diastereomeric derivatives with the chiral reagent S-(-)-N-trifluoroacetyl prolyl chloride. Separation and quantitation of the diastereomeric fenfluramine derivatives are carried out by a capillary gas chromatographic system with flame ionization detection. The assay is linear from 1 to 50 microg/ml for each enantiomer. The analytical method affords average recoveries of 92.28 and 96.44% for l- and d-fenfluramine, respectively. The limits of detection and quantitation for the method are 0.1 and 1.0 microg/ml for the l- and d-fenfluramine isomers, respectively. The reproducibility of the assay was <10% (RSD). The method allowed study of the depletion of l- and d-fenfluramine in rat liver microsomal incubates. The stereoselectivity of fenfluramine phase I metabolism was observed.
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Affiliation(s)
- S Zeng
- School of Pharmacy, Zhejiang University, Hangzhou, People's Republic of China.
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21
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Segura J, Ventura R, Jurado C. Derivatization procedures for gas chromatographic-mass spectrometric determination of xenobiotics in biological samples, with special attention to drugs of abuse and doping agents. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 1998; 713:61-90. [PMID: 9700553 DOI: 10.1016/s0378-4347(98)00089-9] [Citation(s) in RCA: 162] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The development of low cost MS detectors in recent years has promoted an important increase in the applicability of GC-MS system to analyze for the presence of foreign substances in the human body. Drugs and toxic agents are in vivo metabolized in such a way that more polar compounds are usually formed. Derivatization of these metabolites is often an unavoidable requirement for gas chromatographic analysis. Application of derivatization methods in recent years has been relevant, especially for silylation, acylation, alkylation and the formation of cyclic or diastereomeric derivatives. Given the relevance of drug of abuse testing in modern toxicology, main derivatization procedures for opiates, cocaine, cannabis, amphetamines, benzodiazepines and LSD have been reviewed. Papers describing the analyses of drugs of abuse in matrixes other than blood, such as hair or sweat, have received special attention. Advances in derivatization for sports drug testing have been particularly relevant for anabolic steroids, diuretics and corticosteroids. Among the several methodologies applied, the formation of trimethylsilyl, perfluoroacyl or methylated derivatives have proved to be both versatile and extensively used. Further advances in derivatization for GC-MS applications in clinical and forensic toxicology will depend on the one hand on the degree of further use of GC-MS for routine applications and, on the other hand, on the alternative progress made for developments in LC-MS or CE-MS. Last but not least, the appearance of comprehensive libraries in which reference spectra for different derivatives of many drugs and their metabolites are collected will have an important impact on the expansion of derivatization in GC-MS for toxicological applications.
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Affiliation(s)
- J Segura
- Institut Municipal d'Investigació Mèdica IMIM, Drug Research Unit, Barcelona, Spain
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22
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Abstract
The principles and applications of chromatographic separation of enantiomers in pharmaceutical analysis have been reviewed. Several of recently reported enantioselective analysis of various racemic drugs using both the 'indirect' and 'direct' methods have been presented.
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Affiliation(s)
- J Bojarski
- Department of Organic Chemistry, College of Medicine, Jagiellonian University, Krakow, Poland
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