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Enantioresolution and Binding Affinity Studies on Human Serum Albumin: Recent Applications and Trends. CHEMOSENSORS 2021. [DOI: 10.3390/chemosensors9110304] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The interaction between proteins and drugs or other bioactive compounds has been widely explored over the past years. Several methods for analysis of this phenomenon have been developed and improved. Nowadays, increasing attention is paid to innovative methods, such as high performance affinity liquid chromatography (HPALC) and affinity capillary electrophoresis (ACE), taking into account various advantages. Moreover, the development of separation methods for the analysis and resolution of chiral drugs has been an area of ongoing interest in analytical and medicinal chemistry research. In addition to bioaffinity binding studies, both HPALC and ACE al-low one to perform other type of analyses, namely, displacement studies and enantioseparation of racemic or enantiomeric mixtures. Actually, proteins used as chiral selectors in chromatographic and electrophoretic methods have unique enantioselective properties demonstrating suitability for the enantioseparation of a large variety of chiral drugs or other bioactive compounds. This review is mainly focused in chromatographic and electrophoretic methods using human serum albumin (HSA), the most abundant plasma protein, as chiral selector for binding affinity analysis and enantioresolution of drugs. For both analytical purposes, updated examples are presented to highlight recent applications and current trends.
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Ratih R, Wätzig H, Stein M, El Deeb S. Investigation of the enantioselective interaction between selected drug enantiomers and human serum albumin by mobility shift-affinity capillary electrophoresis. J Sep Sci 2020; 43:3960-3968. [PMID: 32823373 DOI: 10.1002/jssc.202000372] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 08/14/2020] [Accepted: 08/15/2020] [Indexed: 12/26/2022]
Abstract
Mobility shift-affinity capillary electrophoresis was employed for enantioseparation and simultaneous binding constant determination. Human serum albumin was used as a chiral selector in the background electrolyte composed of 20 mM phosphate buffer, pH 7.4. The applied setup supports a high mobility shift since albumin and the drug-albumin complex hold negative net charges, while model compounds of amlodipine and verapamil are positively charged. In order to have an accurate effective mobility determination, the Haarhoff-van der Linde function was utilized. Subsequently, the association constant was determined by nonlinear regression analysis of the dependence of effective mobilities on the total protein concentration. Differences in the apparent binding status between the enantiomers lead to mobility shifts of different extends (α). This resulted in enantioresolutions of Rs = 1.05-3.63 for both drug models. R-(+)-Verapamil (KA 1844 M-1 ) proved to bind stronger to human serum albumin compared to S-(-)-verapamil (KA 6.6 M-1 ). The association constant of S-(-)-amlodipine (KA 25 073 M-1 ) was found to be slightly higher compared to its antipode (KA 22 620 M-1 ) when applying the racemic mixture. The low measurement uncertainty of this approach was demonstrated by the close agreement of the association constant of the enantiopure S-(-)-form (KA 25 101 M-1 ).
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Affiliation(s)
- Ratih Ratih
- Institute of Medicinal and Pharmaceutical Chemistry, Technische Universität Braunschweig, Braunschweig, Germany.,Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Surabaya, Surabaya, Indonesia
| | - Hermann Wätzig
- Institute of Medicinal and Pharmaceutical Chemistry, Technische Universität Braunschweig, Braunschweig, Germany
| | - Matthias Stein
- Institute of Medicinal and Pharmaceutical Chemistry, Technische Universität Braunschweig, Braunschweig, Germany
| | - Sami El Deeb
- Institute of Medicinal and Pharmaceutical Chemistry, Technische Universität Braunschweig, Braunschweig, Germany
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Abdel-Hay MH, Ragab MA, Ahmed HM, Mohyeldin SM. Diode array detection and derivative spectroscopic methods for stability study of Oxprenolol and Cyclopenthiazide in liquids. J Mol Liq 2017. [DOI: 10.1016/j.molliq.2017.01.102] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Li X, Xu K, Li H, Yao S, Li Y, Liang B. Qualitative analysis of chiral alanine by UV-visible-shortwave near infrared diffuse reflectance spectroscopy combined with chemometrics. RSC Adv 2016. [DOI: 10.1039/c5ra22488h] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
UV-vis-SWNIR DRS is firstly and successfully used to discriminate the chirality of compounds in powder with a good accuracy.
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Affiliation(s)
- Xiangling Li
- School of Chem. Eng
- Sichuan Univ
- Chengdu 610065
- P. R. China
| | - Kailin Xu
- School of Chem. Eng
- Sichuan Univ
- Chengdu 610065
- P. R. China
| | - Hui Li
- School of Chem. Eng
- Sichuan Univ
- Chengdu 610065
- P. R. China
| | - Shun Yao
- School of Chem. Eng
- Sichuan Univ
- Chengdu 610065
- P. R. China
| | - Yanfang Li
- School of Chem. Eng
- Sichuan Univ
- Chengdu 610065
- P. R. China
| | - Bing Liang
- School of Chem. Eng
- Sichuan Univ
- Chengdu 610065
- P. R. China
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Zheng Y, Wang X, Ji Y. Monoliths with proteins as chiral selectors for enantiomer separation. Talanta 2012; 91:7-17. [DOI: 10.1016/j.talanta.2012.01.039] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Revised: 01/15/2012] [Accepted: 01/18/2012] [Indexed: 12/25/2022]
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Aturki Z, D'Orazio G, Rocco A, Fanali S. Advances in the enantioseparation of β-blocker drugs by capillary electromigration techniques. Electrophoresis 2011; 32:2602-28. [PMID: 21905049 DOI: 10.1002/elps.201100153] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Revised: 04/08/2011] [Accepted: 04/09/2011] [Indexed: 11/07/2022]
Abstract
β-Blocker drugs or β-adrenergic blocking agents are an important class of drugs, prescribed with great frequency. They are used for various diseases, particularly for the treatment of cardiac arrhythmias, cardioprotection after myocardial infarction (heart attack), and hypertension. Almost all β-blocker drugs possess one or more stereogenic centers; however; only some of them are administered as single enantiomers. Since both enantiomers can differ in their pharmacological and toxicological properties, enantioselective analytical methods are required not only for pharmacodynamic and pharmacokinetic studies but also for quality control of pharmaceutical preparations with the determination of enantiomeric purity. In addition to the chromatographic tools, in recent years, capillary electromigration techniques (CE, CEC, and MEKC) have been widely used for enantioselective purposes employing a variety of chiral selectors, e.g. CDs, polysaccharides, macrocyclic antibiotics, proteins, chiral ion-paring agents, etc. The high separation efficiency, rapid analysi,s and low consumption of reagents of electromigration methods make them a very attractive alternative to the conventional chromatographic methods. In this review, the development and applications of electrodriven methods for the enantioseparation of β-blocker drugs are reported. The papers concerning this topic, published from January 2000 until December 2010, are summarised here. Particular attention is given to the coupling of chiral CE and CEC methods to MS, as this detector provides high sensitivity and selectivity.
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Affiliation(s)
- Zeineb Aturki
- Istituto di Metodologie Chimiche, Consiglio Nazionale delle Ricerche, Area della Ricerca di Roma, Monterotondo Scalo, Rome, Italy
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Hu SQ, Chen YL, Zhu HD, Shi HJ, Yan N, Chen XG. Effect of molecular structure of tartrates on chiral recognition of tartrate–boric acid complex chiral selectors in chiral microemulsion electrokinetic chromatography. J Chromatogr A 2010; 1217:5529-35. [DOI: 10.1016/j.chroma.2010.06.063] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2010] [Revised: 06/18/2010] [Accepted: 06/24/2010] [Indexed: 11/26/2022]
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Wang S, Fan L, Cui S. CE-LIF chiral separation of aspartic acid and glutamic acid enantiomers using human serum albumin and sodium cholate as dual selectors. J Sep Sci 2009; 32:3184-90. [DOI: 10.1002/jssc.200900341] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Chu BL, Lin JM, Wang Z, Guo B. Enantiospecific binding of Rotigotine and its antipode to serum albumins: Investigation of binding constants and binding sites by partial-filling ACE. Electrophoresis 2009; 30:2845-52. [DOI: 10.1002/elps.200800521] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Martínez-Gómez MA, Escuder-Gilabert L, Villanueva-Camañas RM, Sagrado S, Medina-Hernández MJ. Enantioseparation of nuarimol by affinity electrokinetic chromatography-partial filling technique using human serum albumin as chiral selector. J Sep Sci 2008; 31:3265-71. [DOI: 10.1002/jssc.200800190] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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13
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Wang Z, Ouyang J, Baeyens WR. Recent developments of enantioseparation techniques for adrenergic drugs using liquid chromatography and capillary electrophoresis: A review. J Chromatogr B Analyt Technol Biomed Life Sci 2008; 862:1-14. [DOI: 10.1016/j.jchromb.2007.11.034] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2007] [Revised: 10/20/2007] [Accepted: 11/23/2007] [Indexed: 10/22/2022]
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Amundsen LK, Sirén H. Determination of association constants between steroid compounds and albumins by partial-filling ACE. Electrophoresis 2007; 28:3737-44. [PMID: 17893945 DOI: 10.1002/elps.200700271] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
ACE is a popular technique for evaluating association constants between drugs and proteins. However, ACE has not previously been applied to study the association between electrically neutral biomolecules and plasma proteins. We studied the affinity between human and bovine serum albumins (HSA and BSA, respectively) and three neutral endogenous steroid hormones (testosterone, epitestosterone and androstenedione) and two synthetic analogues (methyltestosterone and fluoxymesterone) by applying the partial-filling technique in ACE (PF-ACE). From the endocrinological point of view, the distribution of endogenous steroids among plasma components is of great interest. Strong interactions with albumins suppress the biological activity of steroids. Notable differences in the association constants were observed. In the case of the endogenous steroids, the interactions between testosterone and the albumins were strongest, and those between androstenedione and the albumins were substantially weaker. The association constants, K(b), for testosterone, epitestosterone and androstenedione and HSA at 37 degrees C were 32 100 +/- 3600, 21 600 +/- 1500 and 13 300 +/- 1300 M(-1), respectively, while the corresponding values for the steroids and BSA were 18 800 +/- 1500, 14 000 +/- 400 and 7800 +/- 900 M(-1). Methyltestosterone was bound even more strongly than testosterone, while fluoxymesterone was only weakly bound by the albumins. Finally, the steroids were separated by PF-ACE with HSA and BSA used as resolving components.
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Kahle KA, Foley JP. Two-chiral component microemulsion EKC – chiral surfactant and chiral oil. Part 2: Diethyl tartrate. Electrophoresis 2007; 28:2644-57. [PMID: 17597467 DOI: 10.1002/elps.200600747] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In this second study on dual-chirality microemulsions containing a chiral surfactant and a chiral oil, a less hydrophobic and lower interfacial tension chiral oil, diethyl tartrate, is employed (Part 1, Foley, J. P. et al.., Electrophoresis, DOI: 10.1002/elps.200600551). Six stereochemical combinations of dodecoxycarbonylvaline (DDCV: R, S, or racemic, 2.00% w/v), racemic 2-hexanol (1.65% v/v), and diethyl tartrate (D, L, or racemic, 0.88% v/v) were examined as pseudostationary phases (PSPs) for the enantioseparation of six chiral pharmaceutical compounds: pseudoephedrine, ephedrine, N-methyl ephedrine, metoprolol, synephrine, and atenolol. Average efficiencies increased with the addition of a chiral oil to R-DDCV PSP formulations. Modest improvements in resolution and enantioselectivity (alpha(enant)) were achieved with two-chiral-component systems over the one-chiral-component microemulsion. Slight enantioselective synergies were confirmed using a thermodynamic model. Results obtained in this study are compared to those obtained in Part 1 as well as those obtained with chiral MEEKC using an achiral, low-interfacial-tension oil (ethyl acetate). Dual-chirality microemulsions with the more hydrophobic oil dibutyl tartrate yielded, relative to diethyl tartrate, higher efficiencies (100,000-134,000 vs. 80,800-94,300), but lower resolution (1.64-1.91 vs. 2.08-2.21) due to lower enantioselectivities (1.060-1.067 vs. 1.078-1.081). Atenolol enantiomers could not be separated with the dibutyl tartrate-based microemulsions but were partially resolved using diethyl tartrate microemulsions. A comparable single-chirality microemulsion based on the achiral oil ethyl acetate yielded, relative to diethyl tartrate, lower efficiency (78 300 vs. 91 600), higher resolution (1.99 vs. 1.83), and similar enantioselectivities.
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Affiliation(s)
- Kimberly A Kahle
- Department of Chemistry, Drexel University, Philadelphia, PA 19104, USA
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Kahle KA, Foley JP. Review of aqueous chiral electrokinetic chromatography (EKC) with an emphasis on chiral microemulsion EKC. Electrophoresis 2007; 28:2503-26. [PMID: 17657766 DOI: 10.1002/elps.200600808] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The separation of enantiomers using electrokinetic chromatography (EKC) with chiral microemulsions is comprehensively reviewed through December 1, 2006. Aqueous chiral EKC separations based on other pseudostationary phases such as micelles and vesicles or on other chiral selectors such as CDs, crown ethers, glycopeptides, ligand exchange moeities are also reviewed from both mechanistic and applications perspective for the period of January 2005 to December 1, 2006.
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Affiliation(s)
- Kimberly A Kahle
- Department of Chemistry, Drexel University, Philadelphia, PA 19104, USA
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Martínez-Gómez MA, Villanueva-Camañas RM, Sagrado S, Medina-Hernández MJ. Evaluation of enantioselective binding of antihistamines to human serum albumin by ACE. Electrophoresis 2007; 28:2635-43. [PMID: 17605150 DOI: 10.1002/elps.200600742] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The drug binding to plasma and tissue proteins is a fundamental factor in determining the overall pharmacological activity of a drug. HSA, together with alpha(1)-acid glycoprotein, are the most important plasma proteins, which act as drug carriers, with implications on the pharmacokinetic of drugs. Among plasma proteins, HSA possesses the highest enantioselectivity. In this paper, a new methodology for the study of enantiodifferentiation of chiral drugs with HSA is developed and applied to evaluate the possible enantioselective binding of four antihistamines: brompheniramine, chlorpheniramine, hydroxyzine and orphenadrine to HSA. This study includes the determination of affinity constants of drug enantiomers to HSA and the evaluation of the binding sites of antihistamines on the HSA molecule. The developed methodology includes the ultrafiltration of samples containing HSA and racemic antihistaminic drugs and the analysis of the free or bound drug fraction using the affinity EKC-partial filling technique and HSA as chiral selector. The results shown in this paper represent the first evidence of the enantioselective binding of antihistamines to HSA, the major plasmatic protein.
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Affiliation(s)
- María Amparo Martínez-Gómez
- Departamento de Química Analítica, Facultat de Farmacia, Universitat de Valencia, Burjassot, Valencia, Spain
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Martínez-Gómez MA, Sagrado S, Villanueva-Camañas RM, Medina-Hernández MJ. Enantiomeric quality control of antihistamines in pharmaceuticals by affinity electrokinetic chromatography with human serum albumin as chiral selector. Anal Chim Acta 2007; 592:202-9. [PMID: 17512827 DOI: 10.1016/j.aca.2007.04.029] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2007] [Revised: 04/04/2007] [Accepted: 04/16/2007] [Indexed: 10/23/2022]
Abstract
The present paper deals with the enantiomeric separation of six antihistaminic enantiomers by affinity electrokinetic chromatography (AEKC)-partial filling technique using human serum albumin (HSA) as chiral selector. A multivariate optimization approach of the most critical experimental variables in enantioresolution, running pH, HSA concentration and HSA plug length (SPL) was carried out since there are interactions between variables that could not be considered in an univariate optimization. The estimated and experimental resolution values obtained for antihistaminic enantiomers varied from 1.13 (for orphenadrine) to 2.15 (for brompheniramine). The optimum experimental conditions for enantioresolution of each compound were: brompheniramine, pH 8.5, [HSA] 180 microM, SPL 180 s; chlorcyclizine, pH 6.5, [HSA] 180 microM, SPL 150 s; chlorpheniramine, pH 8.25, [HSA] 160 microM, SPL 150 s; hydroxyzine, pH 7.0, [HSA] 180 microM, SPL 150 s; and orphenadrine, pH 7.8, [HSA] 160 microM, SPL 150 s. pH and the quadratic term of pH seem to be the most critical factors that determine enantioresolution of antihistamines. The validity of the developed methodologies to enantiomeric quality control of antihistamines in pharmaceutical formulations is demonstrated analyzing the content of brompheniramine, chlorpheniramine and hyroxyzine enantiomers in commercially available pharmaceutical formulations containing racemic mixtures of compounds. Resolution, accuracy, reproducibility, cost and sample throughput of the proposed methodologies make them suitable for quality control of the enantiomeric composition of antihistamines in pharmaceutical preparations.
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Affiliation(s)
- M A Martínez-Gómez
- Departamento de Química Analítica, Facultat de Farmacia, Universitat de València, C/Vicent Andrés Estellés s/n, E-46100 Burjassot, Valencia, Spain
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Martínez-Gómez MA, Villanueva-Camañas RM, Sagrado S, Medina-Hernández MJ. Potential of human serum albumin as chiral selector of basic drugs in affinity electrokinetic chromatography-partial filling technique. Electrophoresis 2006; 27:4364-74. [PMID: 17024686 DOI: 10.1002/elps.200600216] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The enantiomeric resolution of compounds using HSA by means of affinity EKC (AEKC)-partial filling technique is the result of a delicate balance between different experimental variables such as protein concentration, running pH (background electrophoretic buffer (BGE), protein, and compound solutions), and plug length. In this paper, the possibility of using HSA as chiral selector for enantioseparation of 28 basic drugs using this methodology is studied. The effect of the physicochemical parameters, the structural properties of compounds, and compound-HSA protein binding percentages over their chiral resolution with HSA is outlined. Based on the results obtained, a decision tree is proposed for the "a priori" prediction of the capability of HSA for enantioseparation of basic drugs in AEKC. The results obtained indicated that enantioresolution of basic compounds with HSA depends on the hydrophobicity, polarity, and molar volume of compounds.
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Affiliation(s)
- Maria A Martínez-Gómez
- Departamento de Química Analítica, Facultat de Farmacia, Universitat de Valencia, Burjassot, Valencia, Spain
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Martínez-Gómez MA, Sagrado S, Villanueva-Camañas RM, Medina-Hernández MJ. Enantioseparation of phenotiazines by affinity electrokinetic chromatography using human serum albumin as chiral selector: application to enantiomeric quality control in pharmaceutical formulations. Anal Chim Acta 2006; 582:223-8. [PMID: 17386496 DOI: 10.1016/j.aca.2006.09.036] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2006] [Revised: 09/18/2006] [Accepted: 09/19/2006] [Indexed: 10/24/2022]
Abstract
Nowadays, there is a special interest within the pharmaceutical laboratories to develop single enantiomer formulations and consequently a need for analytical methods to determine the enantiomeric purity of drugs. The present paper deals with the enantiomeric separation of promethazine and trimeprazine enantiomers by affinity electrokinetic chromatography (AEKC)-partial filling technique using human serum albumin (HSA) as chiral selector. A multivariate optimization of the most critical experimental variables in enantioresolution, running pH, HSA concentration and plug length, is carried out to obtain enantioresolution of promethazine and trimeprazine. The estimated maximum and optimum resolution of trimeprazine and prometazine enantiomers (Rs=1.74 and 2.01, respectively) corresponded to the following experimental conditions: pH 7.5; [HSA] 170 microM and plug length 190 s and pH 7.6; [HSA] 170 microM and plug length 170 s, for trimeprazine and prometazine, respectively. The developed methodologies were applied for the enantiomeric quality control of promethazine and trimeprazine enantiomers in commercially available pharmaceutical formulations. Resolution, accuracy, reproducibility, cost and sample throughput of the proposed methodologies make it suitable for quality control of the enantiomeric composition of promethazine and trimeprazine in pharmaceutical preparations.
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Affiliation(s)
- María Amparo Martínez-Gómez
- Departamento de Química Analítica, Facultat de Farmacia, Universitat de València, C/Vicent Andrés Estellés s/n, E-46100 Burjassot, Valencia, Spain
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Abstract
Systems biology depends on a comprehensive assignment and characterization of the interactions of proteins and polypeptides (functional proteomics) and of other classes of biomolecules in a given organism. High‐capacity screening methods are in place for ligand capture and interaction screening, but a detailed dynamic characterization of molecular interactions under physiological conditions in efficiently separated mixtures with minimal sample consumption is presently provided only by electrophoretic interaction analysis in capillaries, affinity CE (ACE). This has been realized in different fields of biology and analytical chemistry, and the resulting advances and uses of ACE during the last 2.5 years are covered in this review. Dealing with anything from small divalent metal ions to large supramolecular assemblies, the applications of ACE span from low‐affinity binding of broad specificity being exploited in optimizing selectivity, e.g., in enantiomer analysis to miniaturized affinity technologies, e.g., for fast processing immunoassay. Also, approaches that provide detailed quantitative characterization of analyte–ligand interaction for drug, immunoassay, and aptamer development are increasingly important, but various approaches to ACE are more and more generally applied in biological research. In addition, the present overview emphasizes that distinct challenges regarding sensitivity, parallel processing, information‐rich detection, interfacing with MS, analyte recovery, and preparative capabilities remain. This will be addressed by future technological improvements that will ensure continuing new applications of ACE in the years to come.
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Affiliation(s)
- Christian Schou
- Department of Autoimmunology, Statens Serum Institute, Copenhagen, Denmark
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Martinez-Gomez MA, Villanueva-Camañas RM, Sagrado S, Medina-Hernández MJ. Multivariate optimization approach for chiral resolution of drugs using human serum albumin in affinity electrokinetic chromatography-partial filling technique. Electrophoresis 2005; 26:4116-26. [PMID: 16252317 DOI: 10.1002/elps.200500304] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The enantiomeric resolution of chiral compounds using HSA by means of affinity EKC (AEKC)-partial filling technique is the result of a delicate balance between different experimental variables such as protein concentration, running pH (background electrophoretic buffer, protein and compound solutions) and protein solution plug length. In this paper multivariate optimization approaches for chiral separation of four basic drugs (alprenolol, oxprenolol, promethazine and propranolol) using HSA as chiral selector in AEKC-partial filling technique are studied. The experimental conditions to achieve maximum resolution are optimized using the Box-Behnken experimental design. Partial least squares and pareto charts are used to analyse the main effects on the resolution. The experimental resolutions observed for all compounds studied in optimum conditions agree with the estimated values based on response surface models. The results obtained show that the range of experimental conditions that provided enantioresolution narrows as hydrophobicity of analytes decreases. This fact can be explained by assuming that hydrophobicity controls the interaction of basic compounds with HSA.
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