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Papp LA, Hancu G, Kelemen H, Tóth G. Chiral separation in the class of proton pump inhibitors by chromatographic and electromigration techniques: An overview. Electrophoresis 2021; 42:1761-1789. [PMID: 34004039 DOI: 10.1002/elps.202100032] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 04/27/2021] [Accepted: 05/05/2021] [Indexed: 11/08/2022]
Abstract
Proton pump inhibitors (PPIs) are benzimidazole-derivative chiral sulfoxides, frequently used in the treatment of gastric hyperacidity-related disorders. Due to their stereoselective metabolism, the eutomeric forms of PPIs can present a more advantageous pharmacokinetic profile by comparison with the distomers or racemates. Moreover, two representatives of the class are used in therapy both as racemates and as pure enantiomers (esomeprazole, dexlansoprazole). A relatively large number of enantioseparation methods employed for the stereoselective determination of PPIs from pharmaceutical, biological, and environmental matrices were published in the past three decades. The purpose of the current overview is to provide a systematic survey of the available chiral separation methods published since the introduction of PPIs in the therapy up to the present. Analytical and bioanalytical methods using different chromatographic and electromigration techniques reported for the enantioseparation of omeprazole, lansoprazole, pantoprazole, rabeprazole, ilaprazole, and tenatoprazole are included. The analytical conditions of the presented methods are summarized in three comprehensive tables, while a critical discussion of the applied techniques, possible mechanism of enantiorecognition, and future perspectives on the topic are also presented.
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Affiliation(s)
- Lajos Attila Papp
- Department of Pharmaceutical Chemistry, "George Emil Palade" University of Medicine, Pharmacy, Sciences and Technology of Târgu Mureș, Romania
| | - Gabriel Hancu
- Department of Pharmaceutical Chemistry, "George Emil Palade" University of Medicine, Pharmacy, Sciences and Technology of Târgu Mureș, Romania
| | - Hajnal Kelemen
- Department of Pharmaceutical Chemistry, "George Emil Palade" University of Medicine, Pharmacy, Sciences and Technology of Târgu Mureș, Romania
| | - Gergő Tóth
- Department of Pharmaceutical Chemistry, Semmelweis University, Budapest, Hungary
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2
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Heravi MM, Zadsirjan V. Prescribed drugs containing nitrogen heterocycles: an overview. RSC Adv 2020; 10:44247-44311. [PMID: 35557843 PMCID: PMC9092475 DOI: 10.1039/d0ra09198g] [Citation(s) in RCA: 309] [Impact Index Per Article: 77.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 11/23/2020] [Indexed: 12/21/2022] Open
Abstract
Heteroatoms as well as heterocyclic scaffolds are frequently present as the common cores in a plethora of active pharmaceuticals natural products. Statistically, more than 85% of all biologically active compounds are heterocycles or comprise a heterocycle and most frequently, nitrogen heterocycles as a backbone in their complex structures. These facts disclose and emphasize the vital role of heterocycles in modern drug design and drug discovery. In this review, we try to present a comprehensive overview of top prescribed drugs containing nitrogen heterocycles, describing their pharmacological properties, medical applications and their selected synthetic pathways. It is worth mentioning that the reported examples are actually limited to current top selling drugs, being or containing N-heterocycles and their synthetic information has been extracted from both scientific journals and the wider patent literature.
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Affiliation(s)
- Majid M Heravi
- Department of Chemistry, School of Science, Alzahra University PO Box 1993891176, Vanak Tehran Iran +98 21 88041344 +98 21 88044051
| | - Vahideh Zadsirjan
- Department of Chemistry, School of Science, Alzahra University PO Box 1993891176, Vanak Tehran Iran +98 21 88041344 +98 21 88044051
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3
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Godage NH, Gionfriddo E. Use of natural sorbents as alternative and green extractive materials: A critical review. Anal Chim Acta 2020; 1125:187-200. [DOI: 10.1016/j.aca.2020.05.045] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 05/18/2020] [Accepted: 05/19/2020] [Indexed: 02/08/2023]
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El-Kimary EI, Ragab MAA. Recent Analytical Methodologies for the Determination of Omeprazole and/or Its Active Isomer Esomeprazole in Different Matrices: A Critical Review. Crit Rev Anal Chem 2020; 52:106-130. [DOI: 10.1080/10408347.2020.1791042] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Eman I. El-Kimary
- Faculty of Pharmacy, Department of Pharmaceutical Analytical Chemistry, University of Alexandria, El-Messalah, Alexandria, Egypt
| | - Marwa A. A. Ragab
- Faculty of Pharmacy, Department of Pharmaceutical Analytical Chemistry, University of Alexandria, El-Messalah, Alexandria, Egypt
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Agranat I, Marom H. In Defense of Secondary Pharmaceutical Patents in Drug Discovery and Development. ACS Med Chem Lett 2020; 11:91-98. [PMID: 32280427 DOI: 10.1021/acsmedchemlett.9b00497] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
"An important objective of modern pharmaceutical research is the discovery of new medical uses for known molecules" (UKSC 2018), a component of secondary pharmaceuticals. This Viewpoint's focus is the defense of the vulnerable strategy of secondary pharmaceutical patents (SPPs). Typical claims thereof are new medical uses, dosage, selection, and enatiomer patents. The attacks on secondary pharmaceuticals, including chiral switches, use negative-connotation terms, such as "evergreening", "product hopping", and "pejorative". Most enantiomer patents, including the controversial Nexium patents, were challenged in courts worldwide yet validated. This Viewpoint considers the "teaching away" defense of nonobviousness of Nexium enantiomer patents due to "unexpected results", applying stereochemistry principles. Physical organic chemistry arguments and the prediction of lower energy barriers of epimerization/racemization of benzylic anions of esomeprazole and dexlansoprazole (compared with their uncharged enantiomers) are a basis of the "teaching away". This prediction is verified by DFT computations. "Obvious to try" of many SPPs should not prevail over "unexpected results". A generalized concern about "evergreening" drugs should not be a justification for comprehensive attacks on SPPs. Following UKSC Lyrica decision (2018), plausibility, a condition of patent validity, may enter the arena of enantiomer patents, claiming second medical uses. Secondary pharmaceutical dosage, selection, improvement, and enantiomer patents are not necessarily obvious.
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Affiliation(s)
- Israel Agranat
- Organic Chemistry, Institute of Chemistry, The Hebrew University of Jerusalem, Philadelphia Bldg. #212, Edmond J. Safra Campus, Jerusalem 9190401, Israel
| | - Hili Marom
- Organic Chemistry, Institute of Chemistry, The Hebrew University of Jerusalem, Philadelphia Bldg. #212, Edmond J. Safra Campus, Jerusalem 9190401, Israel
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Balakin KV, Filosa R, Lavrenov SN, Mkrtchyan AS, Nawrozkij MB, Novakov IA. Arbidol: a quarter-century after. Past, present and future of the original Russian antiviral. RUSSIAN CHEMICAL REVIEWS 2018. [DOI: 10.1070/rcr4791] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The present review is concerned with the synthesis and structure–activity relationship studies of Arbidol and its structural analogues. The latter are roughly divided into several unequal parts: indole- and benzofuran-based compounds, benzimidazole and imidazopyridine bioisosteres and ring-expanded quinoline derivatives. Much attention is focused on various types of antiviral activity of the above-mentioned Arbidol congeners, as well as of the parent compound itself. Features of Arbidol synthesis and metabolic changes are also discussed.
The bibliography includes 166 references.
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El-Kommos ME, Khashaba PY, Ali HRH, El-Wekil MM. Different Chromatographic and Electrophoretic Methods for Analysis of Proton Pump Inhibitors (PPIs): A Review. J LIQ CHROMATOGR R T 2015. [DOI: 10.1080/10826076.2015.1079722] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Michael E. El-Kommos
- Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Assiut University, Assiut, Egypt
| | - Pakinaz Y. Khashaba
- Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Assiut University, Assiut, Egypt
| | - Hassan Refat H. Ali
- Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Assiut University, Assiut, Egypt
| | - Mohamed M. El-Wekil
- Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Assiut University, Assiut, Egypt
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Gallinella B, Ferretti R, Zanitti L, Sestili I, Mosca A, Cirilli R. Comparison of reversed-phase enantioselective HPLC methods for determining the enantiomeric purity of ( S)-omeprazole in the presence of its related substances. J Pharm Anal 2015; 6:132-136. [PMID: 29403973 PMCID: PMC5762455 DOI: 10.1016/j.jpha.2015.11.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 11/03/2015] [Accepted: 11/04/2015] [Indexed: 02/03/2023] Open
Abstract
A simple analytical high-performance liquid chromatography (HPLC) method was applied for the enantiomeric excess determination of esomeprazole ((S)-OME), the enantiopure active ingredient contained in drug products, in the presence of its potential organic impurities A-E. The enantioselective separation was accomplished on the immobilized-type Chiralpak ID-3 chiral stationary phase (CSP) under reversed-phase conditions. The results were evaluated and compared with those obtained by the official enantioselective method of European Pharmacopoeia used as the reference for checking the enantiomeric excess of (S)-OME. It has been established that the use of the Chiralpak ID-3 CSP allows the determination of the enantiomeric purity of (S)-OME without any interference coming from its chiral and achiral related substances. The analytical procedure of the drug regulatory agencies based on the AGP CSP suffered instead from poor specificity due to overlap of the peaks pertinent to the achiral impurity A and the chiral impurity (R)-OME (impurity F).
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Affiliation(s)
- Bruno Gallinella
- Istituto Superiore di Sanità, Dipartimento del Farmaco, Viale Regina Elena 299, I-00161 Rome, Italy
| | - Rosella Ferretti
- Istituto Superiore di Sanità, Dipartimento del Farmaco, Viale Regina Elena 299, I-00161 Rome, Italy
| | - Leo Zanitti
- Istituto Superiore di Sanità, Dipartimento del Farmaco, Viale Regina Elena 299, I-00161 Rome, Italy
| | - Isabella Sestili
- Istituto Superiore di Sanità, Dipartimento del Farmaco, Viale Regina Elena 299, I-00161 Rome, Italy
| | - Antonina Mosca
- Istituto Superiore di Sanità, Dipartimento del Farmaco, Viale Regina Elena 299, I-00161 Rome, Italy
| | - Roberto Cirilli
- Istituto Superiore di Sanità, Dipartimento del Farmaco, Viale Regina Elena 299, I-00161 Rome, Italy
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Barreiro EJ, Kümmerle AE, Fraga CAM. The Methylation Effect in Medicinal Chemistry. Chem Rev 2011; 111:5215-46. [DOI: 10.1021/cr200060g] [Citation(s) in RCA: 518] [Impact Index Per Article: 39.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Eliezer J. Barreiro
- Laboratório de Avaliação e Síntese de Substâncias Bioativas (LASSBio), Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, CCS, Cidade Universitária, CP 68.006, 21941-902 Rio de Janeiro, RJ, Brazil
- Programa de Pós-Graduação em Farmacologia e Química Medicinal, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Cidade Universitária, Ilha do Fundão, Rio de Janeiro, RJ, Brazil
- Programa de Pós-Graduação em Química, Instituto de Química, Universidade Federal do Rio de Janeiro, Cidade Universitária, Ilha do Fundão, Rio de Janeiro, RJ, Brazil
| | - Arthur E. Kümmerle
- Laboratório de Avaliação e Síntese de Substâncias Bioativas (LASSBio), Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, CCS, Cidade Universitária, CP 68.006, 21941-902 Rio de Janeiro, RJ, Brazil
- Programa de Pós-Graduação em Química, Instituto de Química, Universidade Federal do Rio de Janeiro, Cidade Universitária, Ilha do Fundão, Rio de Janeiro, RJ, Brazil
| | - Carlos A. M. Fraga
- Laboratório de Avaliação e Síntese de Substâncias Bioativas (LASSBio), Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, CCS, Cidade Universitária, CP 68.006, 21941-902 Rio de Janeiro, RJ, Brazil
- Programa de Pós-Graduação em Farmacologia e Química Medicinal, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Cidade Universitária, Ilha do Fundão, Rio de Janeiro, RJ, Brazil
- Programa de Pós-Graduação em Química, Instituto de Química, Universidade Federal do Rio de Janeiro, Cidade Universitária, Ilha do Fundão, Rio de Janeiro, RJ, Brazil
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10
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Khomenko TM, Volcho KP, Komarova NI, Salakhutdinov NF. An efficient procedure for the synthesis of Esomeprazole using a titanium complex with two chiral ligands. RUSSIAN JOURNAL OF ORGANIC CHEMISTRY 2011. [DOI: 10.1134/s1070428008010168] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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11
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Zanitti L, Ferretti R, Gallinella B, La Torre F, Sanna ML, Mosca A, Cirilli R. Direct HPLC enantioseparation of omeprazole and its chiral impurities: Application to the determination of enantiomeric purity of esomeprazole magnesium trihydrate. J Pharm Biomed Anal 2010; 52:665-71. [DOI: 10.1016/j.jpba.2010.02.021] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2009] [Revised: 02/15/2010] [Accepted: 02/16/2010] [Indexed: 10/19/2022]
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12
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Marom H, Agranat I. Racemization of the gastrointestinal antisecretory chiral drug esomeprazole magnesium via the pyramidal inversion mechanism: A theoretical study. Chirality 2010; 22:798-807. [DOI: 10.1002/chir.20839] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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13
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Al-Badr AA. Omeprazole. PROFILES OF DRUG SUBSTANCES, EXCIPIENTS, AND RELATED METHODOLOGY 2010; 35:151-262. [PMID: 22469222 DOI: 10.1016/s1871-5125(10)35004-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
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14
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Andersson S, Nelander H, Ohlén K. Preparative chiral chromatography and chiroptical characterization of enantiomers of omeprazole and related benzimidazoles. Chirality 2008; 19:706-15. [PMID: 17348004 DOI: 10.1002/chir.20375] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
To chiroptically characterize the enantiomers of omeprazole and some structurally related benzimidazoles with circular dichroism (CD), preparative chiral liquid chromatography was utilized for the isolation of the pure enantiomers. A limited analytical column screen was performed identifying Kromasil-CHI-TBB and the amylose-based phases Chiralpak AD and AS as possible chiral stationary phases (CSPs) for the preparative scale separation of the enantiomers of the different benzimidazoles. Optimization of the chromatographic conditions with respect to retention, enantioseparation, and resolution was achieved by variation of the mobile phase constituents as well as of temperature. Because of the lability of the compound in slightly acidic media, supercritical fluid chromatography (SFC) could not be applied for a preparative scale separation of the enantiomers. The separation of omeprazole was optimized to give high throughput (2.6 kg racemate/kg CSP/day) and high enantiomeric excess of the obtained isomers. The absolute configurations of the pure enantiomers of rabeprazole, lansoprazole, and pantoprazole were determined from the strong correlation to the CD spectrum of (+)-(R)-omeprazole. For all the compounds, the (+)-enantiomers displayed similar chiroptical features as (+)-(R)-omeprazole and were thus assigned the (R)- configuration. Elution order of the optical isomers was monitored by injecting racemic solutions spiked with one of the isomers and also by an on-line laser polarimeter. Both the type of CSP and also the mobile phase constituents had a strong effect on elution order of the enantiomers.
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Affiliation(s)
- Shalini Andersson
- Medicinal Chemistry, AstraZeneca R&D Mölndal, S-431 83, Mölndal, Sweden.
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15
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High-performance liquid chromatography enantioseparation of proton pump inhibitors using the immobilized amylose-based Chiralpak IA chiral stationary phase in normal-phase, polar organic and reversed-phase conditions. J Chromatogr A 2008; 1177:105-13. [DOI: 10.1016/j.chroma.2007.11.027] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2007] [Revised: 11/06/2007] [Accepted: 11/09/2007] [Indexed: 11/22/2022]
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16
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Felix G, Berthod A. Commercial Chiral Stationary Phases for the Separations of Clinical Racemic Drugs. SEPARATION AND PURIFICATION REVIEWS 2007. [DOI: 10.1080/15422110701826997] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Espinosa Bosch M, Ruiz Sánchez AJ, Sánchez Rojas F, Bosch Ojeda C. Analytical methodologies for the determination of omeprazole: An overview. J Pharm Biomed Anal 2007; 44:831-44. [PMID: 17532167 DOI: 10.1016/j.jpba.2007.04.022] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2007] [Revised: 04/16/2007] [Accepted: 04/17/2007] [Indexed: 10/23/2022]
Abstract
Omeprazole, a gastric acid pump inhibitor, dose-dependently controls gastric acid secretion; the drug has greater antisecretory activity than histamine H(2)-receptor antagonists. Omeprazole has been determined in formulations and biological fluids by a variety of methods such as spectrophotometry, high-performance liquid chromatography with ultraviolet detection and liquid chromatography coupled with tandem mass spectrometry. The overview includes the most relevant analytical methodologies used in its determination since the origin still today.
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Affiliation(s)
- M Espinosa Bosch
- Department of Pharmacy, General Hospital, University Hospital Virgen del Rocío, Manuel Siurot s/n, 41013 Seville, Spain
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18
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Vinković V, Stucchi L, Navarini L, Šunjić V. COMPARISON OF TWO METHODS OF PREPARATION OF THE STATIONARY PHASE FOR HPLC CHIRAL COLUMNS BASED ON tris(3,5-DIMETHYLPHENYLCARBAMOYL) CELLULOSE. J LIQ CHROMATOGR R T 2007. [DOI: 10.1081/jlc-100101716] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Vladimir Vinković
- a Ruđer Bošković Institute , Bijenička 54, P.O. Box 1016, Zagreb , 10001 , Croatia
| | | | | | - Vitomir Šunjić
- a Ruđer Bošković Institute , Bijenička 54, P.O. Box 1016, Zagreb , 10001 , Croatia
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Wei F, Shen B, Chen M. From Analytical Chromatography to Simulated Moving Bed Chromatography: Resolution of Omeprazole Enantiomers. Ind Eng Chem Res 2006. [DOI: 10.1021/ie050529a] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Feng Wei
- Ningbo Institute of Technology, Zhejiang University, Ningbo 315100, People's Republic of China
| | - Bo Shen
- Ningbo Institute of Technology, Zhejiang University, Ningbo 315100, People's Republic of China
| | - Mingjie Chen
- Ningbo Institute of Technology, Zhejiang University, Ningbo 315100, People's Republic of China
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Raju SVN, Purandhar K, Reddy PP, Reddy GM, Reddy LA, Reddy KS, Sreenath K, Mukkanti K, Reddy GS. Preparation of Optically Pure Esomeprazole and Its Related Salt. Org Process Res Dev 2005. [DOI: 10.1021/op049779d] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Satya V. N. Raju
- Research and Development, Dr. Reddy's Laboratories Ltd., Integrated Product Development, Unit-III, Plot No. 116, S.V. Co-Op. Ind. Estate, Bollaram, Jinnaram, Medak District 502 - 325, A.P, India
| | - Koilkonda Purandhar
- Research and Development, Dr. Reddy's Laboratories Ltd., Integrated Product Development, Unit-III, Plot No. 116, S.V. Co-Op. Ind. Estate, Bollaram, Jinnaram, Medak District 502 - 325, A.P, India
| | - Padi Pratap Reddy
- Research and Development, Dr. Reddy's Laboratories Ltd., Integrated Product Development, Unit-III, Plot No. 116, S.V. Co-Op. Ind. Estate, Bollaram, Jinnaram, Medak District 502 - 325, A.P, India
| | - Ghanta Mahesh Reddy
- Research and Development, Dr. Reddy's Laboratories Ltd., Integrated Product Development, Unit-III, Plot No. 116, S.V. Co-Op. Ind. Estate, Bollaram, Jinnaram, Medak District 502 - 325, A.P, India
| | - Lekkala Amarnath Reddy
- Research and Development, Dr. Reddy's Laboratories Ltd., Integrated Product Development, Unit-III, Plot No. 116, S.V. Co-Op. Ind. Estate, Bollaram, Jinnaram, Medak District 502 - 325, A.P, India
| | - Kikkuri Srirami Reddy
- Research and Development, Dr. Reddy's Laboratories Ltd., Integrated Product Development, Unit-III, Plot No. 116, S.V. Co-Op. Ind. Estate, Bollaram, Jinnaram, Medak District 502 - 325, A.P, India
| | - Keshaboina Sreenath
- Research and Development, Dr. Reddy's Laboratories Ltd., Integrated Product Development, Unit-III, Plot No. 116, S.V. Co-Op. Ind. Estate, Bollaram, Jinnaram, Medak District 502 - 325, A.P, India
| | - Kagga Mukkanti
- Research and Development, Dr. Reddy's Laboratories Ltd., Integrated Product Development, Unit-III, Plot No. 116, S.V. Co-Op. Ind. Estate, Bollaram, Jinnaram, Medak District 502 - 325, A.P, India
| | - Ganji Santhi Reddy
- Research and Development, Dr. Reddy's Laboratories Ltd., Integrated Product Development, Unit-III, Plot No. 116, S.V. Co-Op. Ind. Estate, Bollaram, Jinnaram, Medak District 502 - 325, A.P, India
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Abstract
The use of proton pump inhibitors (PPIs) has become widespread in children and infants for the management of paediatric acid-related disease. Pharmacokinetic profiles of only omeprazole and lansoprazole have been well characterised in children over 2 years of age with acid-related diseases. Few data have been recently published regarding the pharmacokinetics of pantoprazole in children, and none are available for rabeprazole or esomeprazole. The metabolism of PPI enantiomers has never been studied in the paediatric population. A one-compartment model best describes the pharmacokinetic behaviour of omeprazole, lansoprazole and pantoprazole in children, with important interindividual variability for each pharmacokinetic parameter. Like adults, PPIs are rapidly absorbed in children following oral administration; the mean time to reach maximum plasma concentration varies from 1 to 3 hours. Since these agents are acid labile, their oral formulations consist of capsules containing enteric-coated granules. No liquid formulation is available for any of the PPIs. Thus, for those patients unable to swallow capsules, extemporaneous liquid preparations for omeprazole and lansoprazole have been reported; however, neither the absolute nor the relative bioavailabilities of these oral formulations have been studied in children. Intravenous formulations are available for omeprazole (in Europe), lansoprazole and pantoprazole. PPIs are rapidly metabolised in children, with short elimination half-lives of around 1 hour, similar to that reported for adults. All PPIs are extensively metabolised by the liver, primarily by cytochrome P450 (CYP) isoforms CYP2C19 and CYP3A4, to inactive metabolites, with little unchanged drug excreted in the urine. Similar to that seen in adults, the absolute bioavailability of omeprazole increases with repeated dosing in children; this phenomenon is thought to be due to a combination of decreased first-pass elimination and reduced systemic clearance. The apparent clearance (CL/F) of omeprazole, lansoprazole and pantoprazole appears to be faster for children than for adults. A higher metabolic capacity in children as well as differences in the extent of PPI bioavailability are most likely responsible for this finding. This may partly account for the need in children for variable and sometimes considerably greater doses of PPIs, on a per kilogram basis, than for adults to achieve similar plasma concentrations. Furthermore, no studies have been able to demonstrate a statistically significant correlation between age and pharmacokinetic parameters among children. Despite the small number of very young infants studied, there is some evidence for reduced PPI metabolism in newborns. The limited paediatric data regarding the impact of CYP2C19 genetic polymorphism on PPI metabolism are similar to those reported for adults, with poor metabolisers having 6- to 10-fold higher area under the concentration-time curve values compared with extensive metabolisers. Finally, because a pharmacokinetic/pharmacodynamic relationship exists for PPIs, the significant interindividual variability in their disposition may partly explain the wide range of therapeutic doses used in children. Further studies are needed to better define the pharmacokinetics of PPIs in children <2 years of age.
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Abstract
Proton pump inhibitors are used at different dosages for the treatment of acid-related gastrointestinal disorders, such as gastro-oesophaeal reflux and peptic ulcer disease. Comparisons of four different proton pump inhibitors: lansoprazole, omeprazole, pantoprazole, and rabeprazole show that they all have similar potency and efficacy. Rabeprazole, however, displays a slightly more rapid onset of acid inhibition than the others; the clinical advantage of this seems limited. The S-isomer of omeprazole, esomeprazole, exhibits a somewhat higher potency than the other proton pump inhibitors. Reports supporting a clinical advantage of this property are not convincing. To conclude, all inhibitors seem comparable as regards inhibition of gastric acid secretion.
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Affiliation(s)
- Per M Hellström
- Unit of Gastroenterology and Hepatology, Department of Medicine, Karolinska Hospital, Stockholm, Sweden.
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Orlando RM, Bonato PS. Simple and efficient method for enantioselective determination of omeprazole in human plasma. J Chromatogr B Analyt Technol Biomed Life Sci 2004; 795:227-35. [PMID: 14522027 DOI: 10.1016/s1570-0232(03)00570-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
A practical and selective HPLC method for the separation and quantification of omeprazole enantiomers in human plasma is presented. C18 solid phase extraction (SPE) cartridges were used to extract the enantiomers from plasma samples and the chiral separation was carried out on a Chiralpak AD column protected with a CN guard column, using ethanol:hexane (70:30) as the mobile phase, at a flow rate of 0.5 ml/min. The detection was carried out at 302 nm. The method proved to be linear in the range of 10-1000 ng/ml for each enantiomer, with a quantification limit of 5 ng/ml. Precision and accuracy, demonstrated by within-day and between-day assays, were lower than 10%.
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Affiliation(s)
- Ricardo Mathias Orlando
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto CEP 14040-903, Brazil
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24
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Federsel HJ. Facing chirality in the 21st century: Approaching the challenges in the pharmaceutical industry. Chirality 2003; 15 Suppl:S128-42. [PMID: 12884384 DOI: 10.1002/chir.10274] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
How is process R&D organized and operated in today's pharmaceutical industry at the dawn of the 21st century? A way to respond to the challenges with regard to reduced time to market is to build on early involvement and a front-loading approach. This means that activities are initiated during the lead optimization phase starting up to 2 years ahead of candidate drug nomination and a model built on this concept covering the stages through to commercial launch is advocated as the appropriate way forward. However, given the high attrition rate in a pharma R&D pipeline focused risk management needs to be applied and options judiciously evaluated. From a molecular perspective, the chemical targets in many instances present a formidable complexity both with regard to the overall structure but increasingly also when it comes to their stereochemical features. Thus, a novel triazolo pyrimidine compound with six stereogenic centers requiring 28 transformations for its assembly is examined to underscore this, but also the difficulties in designing a feasible route for the relatively simple (S)-azetidinecarboxylic acid are highlighted. Furthermore, the successful development of a unique and highly efficient catalytic asymmetric sulfide oxidation to the corresponding (S)-sulfoxide esomeprazole is discussed, together with the remarkable effect that normal sea sand has on the stereoselectivity of a steroid trans-acetalization.
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25
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Lindberg P, Keeling D, Fryklund J, Andersson T, Lundborg P, Carlsson E. Review article: Esomeprazole--enhanced bio-availability, specificity for the proton pump and inhibition of acid secretion. Aliment Pharmacol Ther 2003; 17:481-8. [PMID: 12622756 DOI: 10.1046/j.1365-2036.2003.01481.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Esomeprazole, the S-isomer of omeprazole, is the first proton pump inhibitor available for clinical use as a single isomer. It demonstrates pharmacological and clinical benefits beyond those seen with the racemic omeprazole. Esomeprazole has higher and more consistent bio-availability than omeprazole, which results in a greater area under the plasma concentration-time curve. It is the area under the plasma concentration-time curve of omeprazole and esomeprazole that determines how much of each reaches the parietal cell, and thus the control of gastric acid secretion that is achieved. Esomeprazole, like other proton pump inhibitors, has a high specificity for the acidic environment of the parietal cell, where it is accumulated, activated and covalently inhibits the proton pump. Proton pumps elsewhere in the body do not achieve the level of acidity needed for accumulation and activation. Esomeprazole, 40 mg once daily, provides more effective control of gastric acid secretion than omeprazole, 20 or 40 mg once daily, and all other proton pump inhibitors given at their standard doses. This translates into greater clinical effect compared with omeprazole, 20 mg once daily, and lansoprazole, 30 mg once daily, in the management of reflux disease. Esomeprazole therapy is well tolerated, with a low adverse events profile, similar to that seen with omeprazole.
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Affiliation(s)
- P Lindberg
- Gastrointestinal Therapy Area, AstraZeneca R&D, Mölndal, Sweden.
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26
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Olbe L, Carlsson E, Lindberg P. A proton-pump inhibitor expedition: the case histories of omeprazole and esomeprazole. Nat Rev Drug Discov 2003; 2:132-9. [PMID: 12563304 DOI: 10.1038/nrd1010] [Citation(s) in RCA: 245] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Lars Olbe
- AstraZeneca R&D, 431 83 Mölndal, Sweden.
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27
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Agranat I, Caner H, Caldwell J. Putting chirality to work: the strategy of chiral switches. Nat Rev Drug Discov 2002; 1:753-68. [PMID: 12360254 DOI: 10.1038/nrd915] [Citation(s) in RCA: 379] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Most of the new drugs reaching the market today are single enantiomers, rather than the racemic mixtures that dominated up to ten years ago. Many of the new single-enantiomer drugs were developed as such, but there are also important examples of new single-enantiomer drugs derived from 'chiral switches' of established racemates. Indeed, a well-timed chiral switch can offer enhanced therapy and further profitability as a 'line extension' of a major racemic drug with patents that are expiring.
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Affiliation(s)
- Israel Agranat
- Division of Biomedical Sciences, Imperial College Faculty of Medicine, Sir Alexander Fleming Building, London SW7 2AZ, United Kingdom.
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28
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Ståhlberg J, Henriksson H, Divne C, Isaksson R, Pettersson G, Johansson G, Jones TA. Structural basis for enantiomer binding and separation of a common beta-blocker: crystal structure of cellobiohydrolase Cel7A with bound (S)-propranolol at 1.9 A resolution. J Mol Biol 2001; 305:79-93. [PMID: 11114249 DOI: 10.1006/jmbi.2000.4237] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Cellobiohydrolase Cel7A (previously called CBH 1), the major cellulase produced by the mould fungus Trichoderma reesei, has been successfully exploited as a chiral selector for separation of stereo-isomers of some important pharmaceutical compounds, e.g. adrenergic beta-blockers. Previous investigations, including experiments with catalytically deficient mutants of Cel7A, point unanimously to the active site as being responsible for discrimination of enantiomers. In this work the structural basis for enantioselectivity of basic drugs by Cel7A has been studied by X-ray crystallography. The catalytic domain of Cel7A was co-crystallised with the (S)-enantiomer of a common beta-blocker, propranolol, at pH 7, and the structure of the complex was determined and refined at 1. 9 A resolution. Indeed, (S)-propranolol binds at the active site, in glucosyl-binding subsites -1/+1. The catalytic residues Glu212 and Glu217 make tight salt links with the secondary amino group of (S)-propranolol. The oxygen atom attached to the chiral centre of (S)-propranolol forms hydrogen bonds to the nucleophile Glu212 O(epsilon1) and to Gln175 N(epsilon2), whereas the aromatic naphthyl moiety stacks with the indole ring of Trp376 in site +1. The bidentate charge interaction with the catalytic glutamate residues is apparently crucial, since no enantioselectivity has been obtained with the catalytically deficient mutants E212Q and E217Q. Activity inhibition experiments with wild-type Cel7A were performed in conditions close to those used for crystallisation. Competitive inhibition constants for (R)- and (S)-propranolol were determined at 220 microM and 44 microM, respectively, corresponding to binding free energies of 20 kJ/mol and 24 kJ/mol, respectively. The K(i) value for (R)-propranolol was 57-fold lower than the highest concentration, 12.5 mM, used in co-crystallisation experiments. Still several attempts to obtain a complex with the (R)-enantiomer have failed. By using cellobiose as a selective competing ligand, the retention of the enantiomers of propranolol on the chiral stationary phase (CSP) based on Cel7A mutant D214N were resolved into enantioselective and non- selective binding. The enantioselective binding was weaker for both enantiomers on D214N-CSP than on wild-type-CSP.
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Affiliation(s)
- J Ståhlberg
- Department of Molecular Biology, University of Uppsala, Uppsala, SE-751 24, Sweden
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29
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Cotton H, Elebring T, Larsson M, Li L, Sörensen H, von Unge S. Asymmetric synthesis of esomeprazole. ACTA ACUST UNITED AC 2000. [DOI: 10.1016/s0957-4166(00)00352-9] [Citation(s) in RCA: 205] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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30
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Abstract
(+/-)-Pantoprazole ((+/-)-PAN), (+/-)-5-(difluoromethoxy)-2-[[3.4-dimethoxy-2-pyridinyl)methyl]sul finyl]- 1H-benzimidazole) is a chiral sulfoxide that is used clinically as a racemic mixture. The disposition kinetics of (+)-PAN and (-)-PAN given separately has been studied in rats. Serum levels of (+)- and (-)-PAN and its metabolites, pantoprazole sulfone (PAN-SO2), pantoprazole sulfide (PAN-S), 4'-O-demethyl pantoprazole sulfone (DMPAN-SO2), and 4'-O-demethyl pantoprazole sulfide (DMPAN-S) were measured by HPLC. Following single intravenous or oral administration, both enantiomers were rapidly absorbed and metabolized, resulting in similar serum concentrations, suggesting that the two enantiomers have approximately the same disposition kinetics. The major metabolite of both (+)- and (-)-PAN was PAN-SO2, while DMPAN-SO2 was also detected as a minor metabolite. Serum levels of PAN-S and DMPAN-S could not be quantified after intravenous or oral administration of either enantiomer. Significant chiral inversion occurred after intravenous and oral administration of (+)-PAN. The AUCs of (-)-PAN after intravenous and oral dosing of (+)-PAN were 36.3 and 28.1%, respectively of those of total [(+) + (-)] PAN. In contrast, the serum levels of (+)-PAN were below quantitation limits after intravenous or oral administration of (-)-PAN. Therefore, chiral inversion was observed only after administration of (+)-PAN, supporting the hypothesis that stereoselective inversion from (+)-PAN to (-)-PAN occurs in rats.
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Affiliation(s)
- N Masubuchi
- Drug Metabolism and Analytical Chemistry Research Laboratory, Daiichi Pharmaceutical Co., Ltd., Tokyo, Japan
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31
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Stenhoff H, Blomqvist A, Lagerström PO. Determination of the enantiomers of omeprazole in blood plasma by normal-phase liquid chromatography and detection by atmospheric pressure ionization tandem mass spectrometry. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 1999; 734:191-201. [PMID: 10595717 DOI: 10.1016/s0378-4347(99)00324-2] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
An enantioselective assay of omeprazole in blood plasma using normal-phase liquid chromatography on a Chiralpak AD column and detection by mass spectrometry is described. Omeprazole is extracted by a mixture of dichloromethane and hexane and, after evaporation, redissolution and injection, separated into its enantiomers on the chiral stationary phase. Detection is made by a triple quadrupole mass spectrometer, using deuterated analogues as internal standards. The method enables determination in plasma down to 10 nmol/l (LOQ) and shows excellent consistency suited for pharmacokinetic studies in man.
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Affiliation(s)
- H Stenhoff
- Bioanalytical Chemistry, AstraZeneca R&D Mölndal, Sweden
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32
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33
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Tybring G, Böttiger Y, Widén J, Bertilsson L. Enantioselective hydroxylation of omeprazole catalyzed by CYP2C19 in Swedish white subjects. Clin Pharmacol Ther 1997; 62:129-37. [PMID: 9284848 DOI: 10.1016/s0009-9236(97)90060-6] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Stereoselective disposition of omeprazole and its formed 5-hydroxy metabolite were studied in five poor metabolizers and five extensive metabolizers of S-mephenytoin. After a single oral dose of omeprazole (20 mg), the plasma concentrations of the separate enantiomers of the parent drug and the 5-hydroxy metabolite were determined for 10 hours after drug intake. In poor metabolizers, the area under the plasma concentration versus time curve [AUC(0-8)] of (+)-omeprazole was larger and that of the 5-hydroxy metabolite of this enantiomer was smaller than the AUC(0-8) values in extensive metabolizers (p < 0.001). The mean AUC(0-8) of the (-)-enantiomer of omeprazole was also higher in poor metabolizers than in extensive metabolizers, but only 3.1-fold compared with 7.5-fold for (+)-omeprazole. The rate of formation of the hydroxy metabolite from (-)-omeprazole was low and not significantly different in poor and extensive metabolizers. These results show that (+)-omeprazole is to a major extent hydroxylated by CYP2C19. Also (-)-omeprazole may partly be metabolized by this enzyme but is mainly metabolized by another enzyme, presumably CYP3A4, to the achiral sulfone metabolite. The plasma concentration ratio of omeprazole to 5-hydroxyomeprazole obtained 3 hours after the drug intake has been used to distinguish between extensive and poor metabolizer phenotypes. With use of the ratio between the (+)-enantiomers of the parent drug and the metabolite, a better discrimination between phenotypes was obtained. The ratio between the (-)-enantiomers also separated the phenotypes but was less discriminatory. For the future, measurement of total concentrations will suffice for phenotyping.
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Affiliation(s)
- G Tybring
- Department of Medical Laboratory Sciences and Technology, Karolinska Institute, Huddinge University Hospital, Sweden
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34
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Stereochemical assignment of the enantiomers of omeprazole from X-ray analysis of a fenchyloxymethyl derivative of (+)-(R)-omeprazole. ACTA ACUST UNITED AC 1997. [DOI: 10.1016/s0957-4166(97)00195-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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35
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Eberle D, Hummel RP, Kuhn R. Chiral resolution of pantoprazole sodium and related sulfoxides by complex formation with bovine serum albumin in capillary electrophoresis. J Chromatogr A 1997; 759:185-92. [PMID: 9050224 DOI: 10.1016/s0021-9673(96)00769-8] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The separation of enantiomers of pantoprazole sodium, omeprazole and lansoprazole by capillary zone electrophoresis using bovine serum albumin (BSA) as the chiral selector is described. Baseline separation of the three structurally related drugs was obtained after optimization of the most important experimental parameters. For this purpose, influences such as BSA concentration, pH and concentration of 1-propanol as organic modifier on the separation were investigated. Increasing concentrations of BSA improved the chiral resolution but lowered the sensitivity of the detection system. Discrimination of the enantiomers was observed only in a narrow pH range of 7-8. An optimum of pH 7.4 was a good compromise in terms of enantio-resolution and peak shape. 1-Propanol when added to the buffer system, improved the peak shape of the analytes and the resolution. The optimized method has been validated for pantoprazole sodium and is useful for routine analysis.
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Affiliation(s)
- D Eberle
- Research Laboratories Byk Gulden, Konstanz, Germany
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36
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Tanaka M, Yamazaki H. Direct determination of pantoprazole enantiomers in human serum by reversed-phase high-performance liquid chromatography using a cellulose-based chiral stationary phase and column-switching system as a sample cleanup procedure. Anal Chem 1996; 68:1513-6. [PMID: 8815744 DOI: 10.1021/ac951127n] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A direct stereoselective reversed-phase HPLC method is described for the determination of the enantiomers of a proton pump inhibitor, pantoprazole (PAN), in human serum. The enantiomers were separated with high resolution on a cellulose-based chiral stationary phase (Chiralcel OJ-R) following on-line solid phase sample cleanup with a column-switching device. A mixture of acetonitrile and 50 mM sodium perchlorate was used as the mobile phase at a flow rate of 0.5 mliter/min. Pantoprazole enantiomers were detected by monitoring the column effluent with UV light at a wavelength of 290 nm. The calibration curve for each enantiomer was linear from 0.1 to 5.0 micrograms/mliter. Under these conditions, the determination of pantoprazole enantiomers in human serum can be achieved with satisfactory selectivity, sensitivity, precision, and accuracy. The described procedure is very simple and rapid since labor-intensive sample preparation is not required. The method was applied to the analyses of the serum samples obtained from a volunteer who received an 80-mg oral dose of racemic PAN. The samples showed the (+)/(-) isomer ratios ranging from 0.74 to 1.03 up to 6 h after dosing, indicating that there is only a small difference in the concentrations of (+)- and (-)-PAN.
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Affiliation(s)
- M Tanaka
- Drug Metabolism and Analytical Chemistry Research Laboratory, Daiichi Pharmaceutical Co. Ltd., Tokyo, Japan
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37
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Francotte E, Zhang T. Supramolecular effects in the chiral discrimination of meta-methylbenzoyl cellulose in high-performance liquid chromatography. J Chromatogr A 1995. [DOI: 10.1016/0021-9673(95)00686-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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38
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Tanaka M, Yamazaki H, Hakusui H. Direct HPLC separation of enantiomers of pantoprazole and other benzimidazole sulfoxides using cellulose-based chiral stationary phases in reversed-phase mode. Chirality 1995. [DOI: 10.1002/chir.530070810] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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39
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Francotte E. Contribution of preparative chromatographic resolution to the investigation of chiral phenomena. J Chromatogr A 1994. [DOI: 10.1016/0021-9673(94)80419-2] [Citation(s) in RCA: 113] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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40
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Resolution by high-performance liquid chromatography using polysaccharide carbamates and benzoates as chiral stationary phases. J Chromatogr A 1994. [DOI: 10.1016/0021-9673(94)80400-1] [Citation(s) in RCA: 456] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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41
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Balmér K, Persson BA, Lagerström PO. Stereoselective effects in the separation of enantiomers of omeprazole and other substituted benzimidazoles on different chiral stationary phases. J Chromatogr A 1994. [DOI: 10.1016/0021-9673(94)85121-2] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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42
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Matlin SA, Tiritan ME, Crawford AJ, Cass QB, Boyd DR. HPLC with carbohydrate carbamate chiral phases: Influence of chiral phase structure on enantioselectivity. Chirality 1994. [DOI: 10.1002/chir.530060214] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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43
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Khan AZQ, Sandström J. Enantiomer and diastereoisomer resolution, rotational barriers, and CD and UV spectra of some twisted push–pull ethylenes. ACTA ACUST UNITED AC 1994. [DOI: 10.1039/p29940001575] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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44
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Abstract
Pharmaceutical enantiomers often exhibit different pharmacodynamic and pharmacokinetic properties. Stereospecific chromatographic assays are available to separate these stereoisomers. Therapeutic agents often contain chemical functional groups (e.g. amino, hydroxyl, carbonyl, and carboxylic acid). These can be reacted with enantiomerically pure reagents to give diastereoisomers suitable for analysis on achiral gas chromatographic (GC) and high performance liquid chromatographic (HPLC) columns. Alternatively, derivatized or underivatized drugs may be resolved on chiral chromatographic phases. A wide variety of GC (e.g. amino acid, cyclodextrin, and metal-complex) and HPLC (mobile phase additive, crown ether, pi-pi interaction and related phases, protein, cyclodextrin, polysaccharide, methacrylate and amide polymer, and ligand exchange) columns are commercially available. This article reviews the chromatographic separation of enantiomers.
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Affiliation(s)
- F M Pasutto
- Faculty of Pharmacy & Pharmaceutical Sciences, University of Alberta, Edmonton, Canada
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45
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Kobayashi K, Chiba K, Sohn DR, Kato Y, Ishizaki T. Simultaneous determination of omeprazole and its metabolites in plasma and urine by reversed-phase high-performance liquid chromatography with an alkaline-resistant polymer-coated C18 column. JOURNAL OF CHROMATOGRAPHY 1992; 579:299-305. [PMID: 1429977 DOI: 10.1016/0378-4347(92)80395-7] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Omeprazole (OPZ) is a proton pump inhibitor in gastric parietal cells. A reversed-phase high-performance liquid chromatographic method was developed that enables concentrations of OPZ and its major metabolites, omeprazole sulphone (OPZ-SFN) and hydroxy-omeprazole (H-OPZ), to be determined simultaneously in plasma and that of H-OPZ in urine. To prevent decomposition of OPZ, all the processes (extraction, injection and elution) were carried out under alkaline conditions. Recoveries of the analytes and internal standard were greater than 93.1%. The intra- and inter-assay coefficients of variation were less than 9.1 and 6.4% for plasma samples and less than 2.9 and 3.9% for urine samples, respectively. The minimum determinable concentration (relative standard deviation 10-15%) was 10 ng/ml for all analytes in plasma and H-OPZ in urine samples. The clinical applicability of this assay method was evaluated by determining plasma concentration-and urinary excretion-time courses of the respective analyte(s) in four healthy volunteers after an oral dose of 20 mg of OPZ. The present assay is considered to be simple, precise and accurate and suitable for the study of the kinetic disposition and metabolism of OPZ, which is an extensively metabolized drug in the human liver.
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Affiliation(s)
- K Kobayashi
- Division of Clinical Pharmacology, National Medical Center, Tokyo, Japan
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