1
|
Krebs F, Zagst H, Stein M, Ratih R, Minkner R, Olabi M, Hartung S, Scheller C, Lapizco-Encinas BH, Sänger-van de Griend C, García CD, Wätzig H. Strategies for capillary electrophoresis: Method development and validation for pharmaceutical and biological applications-Updated and completely revised edition. Electrophoresis 2023; 44:1279-1341. [PMID: 37537327 DOI: 10.1002/elps.202300158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 07/19/2023] [Indexed: 08/05/2023]
Abstract
This review is in support of the development of selective, precise, fast, and validated capillary electrophoresis (CE) methods. It follows up a similar article from 1998, Wätzig H, Degenhardt M, Kunkel A. "Strategies for capillary electrophoresis: method development and validation for pharmaceutical and biological applications," pointing out which fundamentals are still valid and at the same time showing the enormous achievements in the last 25 years. The structures of both reviews are widely similar, in order to facilitate their simultaneous use. Focusing on pharmaceutical and biological applications, the successful use of CE is now demonstrated by more than 600 carefully selected references. Many of those are recent reviews; therefore, a significant overview about the field is provided. There are extra sections about sample pretreatment related to CE and microchip CE, and a completely revised section about method development for protein analytes and biomolecules in general. The general strategies for method development are summed up with regard to selectivity, efficiency, precision, analysis time, limit of detection, sample pretreatment requirements, and validation.
Collapse
Affiliation(s)
- Finja Krebs
- Institute, of Medicinal and Pharmaceutical Chemistry, Technische Universität Braunschweig, Braunschweig, Lower Saxony, Germany
| | - Holger Zagst
- Institute, of Medicinal and Pharmaceutical Chemistry, Technische Universität Braunschweig, Braunschweig, Lower Saxony, Germany
| | - Matthias Stein
- Institute, of Medicinal and Pharmaceutical Chemistry, Technische Universität Braunschweig, Braunschweig, Lower Saxony, Germany
| | - Ratih Ratih
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Surabaya, Surabaya, East Java, Indonesia
| | - Robert Minkner
- Institute, of Medicinal and Pharmaceutical Chemistry, Technische Universität Braunschweig, Braunschweig, Lower Saxony, Germany
| | - Mais Olabi
- Institute, of Medicinal and Pharmaceutical Chemistry, Technische Universität Braunschweig, Braunschweig, Lower Saxony, Germany
| | - Sophie Hartung
- Institute, of Medicinal and Pharmaceutical Chemistry, Technische Universität Braunschweig, Braunschweig, Lower Saxony, Germany
| | - Christin Scheller
- Institute, of Medicinal and Pharmaceutical Chemistry, Technische Universität Braunschweig, Braunschweig, Lower Saxony, Germany
| | - Blanca H Lapizco-Encinas
- Department of Biomedical Engineering, Kate Gleason College of Engineering, Rochester Institute of Technology, Rochester, New York, USA
| | - Cari Sänger-van de Griend
- Kantisto BV, Baarn, The Netherlands
- Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala Universitet, Uppsala, Sweden
| | - Carlos D García
- Department of Chemistry, Clemson University, Clemson, South Carolina, USA
| | - Hermann Wätzig
- Institute, of Medicinal and Pharmaceutical Chemistry, Technische Universität Braunschweig, Braunschweig, Lower Saxony, Germany
| |
Collapse
|
2
|
Fernández-Pumarega A, Olmo L, Amézqueta S, Fuguet E, Rosés M. Comparison of the retention of basic compounds in anionic and cationic microemulsion electrokinetic chromatographic systems. Microchem J 2020. [DOI: 10.1016/j.microc.2020.105259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
3
|
Fernández-Pumarega A, Amézqueta S, Fuguet E, Rosés M. Estimation of the octanol-water distribution coefficient of acidic compounds by microemulsion electrokinetic chromatography. J Pharm Biomed Anal 2020; 179:112981. [PMID: 31822379 DOI: 10.1016/j.jpba.2019.112981] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 11/04/2019] [Accepted: 11/09/2019] [Indexed: 10/25/2022]
Abstract
The feasibility of extending the determination of the lipophilicity of partially ionized acids (log Do/w) by microemulsion electrokinetic chromatography (MEEKC) is tested. Theoretical considerations predict that a linear log Do/w vs. log k correlation can be obtained only when the neutral and ionic forms of an acid follow the same correlation equation and the slope of the correlation is unity. In practice, since the lipophilicity of the neutral acid is much higher than that of the ionic form and the correlation slope is not very different from 1, the general linear correlation for neutral compounds can be applied across most of the ionization range of the acid. The linear correlation between log Po/w and log k of 20 neutral solutes (calibration curve) has been established and extended to 6 acids used as models, tested across their full ionization range. log Do/w-pH, and log k-pH profiles have been obtained for these 6 acids, and plotted log Do/w against log k for any acid at any degree of ionization. Furthermore, the log Do/w of the acids has been estimated from the calibration curve and log k-pH profile, and compared to values in the literature determined using reference methods such as the shake-flask one. Accurate values have been obtained using the MEEKC method when the acids are in their neutral form or partially ionized (ionization degree, α < 0.995). However, this parameter is overestimated when the acids are highly or fully ionized (α ≈ 1). Finally, in order to test the applicability of this method, we have applied the same procedure to estimate log Do/w at pH = 7.4 (blood physiological pH) of a set of 30 additional compounds (including partially and fully ionized acids). The results at this pH follow the same trend observed in the 6 model acids, and validate the application of the method for Do/w determination, except when α is very close to 1.
Collapse
Affiliation(s)
- Alejandro Fernández-Pumarega
- Departament d'Enginyeria Química i Química Analítica and Institut de Biomedicina (IBUB), Facultat de Química, Universitat de Barcelona, Martí i Franquès 1-11, 08028, Barcelona, Spain
| | - Susana Amézqueta
- Departament d'Enginyeria Química i Química Analítica and Institut de Biomedicina (IBUB), Facultat de Química, Universitat de Barcelona, Martí i Franquès 1-11, 08028, Barcelona, Spain.
| | - Elisabet Fuguet
- Departament d'Enginyeria Química i Química Analítica and Institut de Biomedicina (IBUB), Facultat de Química, Universitat de Barcelona, Martí i Franquès 1-11, 08028, Barcelona, Spain; Serra Húnter Programme. Generalitat de Catalunya, Spain
| | - Martí Rosés
- Departament d'Enginyeria Química i Química Analítica and Institut de Biomedicina (IBUB), Facultat de Química, Universitat de Barcelona, Martí i Franquès 1-11, 08028, Barcelona, Spain
| |
Collapse
|
4
|
Penny WM, Palmer CP. Determination of lipid bilayer affinities and solvation characteristics by electrokinetic chromatography using polymer-bound lipid bilayer nanodiscs. Electrophoresis 2018; 39:844-852. [PMID: 29072338 PMCID: PMC5832619 DOI: 10.1002/elps.201700308] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2017] [Revised: 10/12/2017] [Accepted: 10/12/2017] [Indexed: 12/27/2022]
Abstract
Styrene-maleic acid polymer-bound lipid bilayer nanodiscs have been investigated and characterized by electrokinetic chromatography. Linear solvation energy relationship analysis was employed to characterize the changes in solvation environment of nanodiscs of varied belt to lipid ratio, belt polymer chemistry and molecular weight, and lipid composition. Increases in the lipid to belt polymer ratio resulted in smaller, more cohesive nanodiscs with greater electrophoretic mobility. Nanodisc structures with belt polymers of different chemistry and molecular weight were compared and showed only minor changes in solvent characteristics and selectivity consistent with changes in structure of the lipid bilayer. Seven phospholipid and sphingomyelin nanodiscs of different lipid composition were characterized. Changes in lipid head group structure had a significant effect on bilayer-solute interactions. In most cases, changes in alkyl tail structure had no discernible effect on solvation environment aside from those explained by changes in the gel-liquid transition temperature. Comparison to vesicles of similar lipid composition show only minor differences in solvation environment, likely due to differences in lipid composition and bilayer curvature. Together these results provide evidence that the dominant solute-nanodisc interactions are with the lipid bilayer and that head group chemistry has a greater impact on bilayer-solute interactions than alkyl tail or belt polymer structure. Nanodisc electrokinetic chromatography is demonstrated to allow characterization of solute interactions with lipid bilayers of varied composition.
Collapse
Affiliation(s)
- William M Penny
- Department of Chemistry and Biochemistry, University of Montana, Missoula, MT, USA
| | - Christopher P Palmer
- Department of Chemistry and Biochemistry, University of Montana, Missoula, MT, USA
| |
Collapse
|
5
|
Penny WM, Steele HB, Ross JBA, Palmer CP. Phospholipid bilayer affinities and solvation characteristics by electrokinetic chromatography with a nanodisc pseudostationary phase. Electrophoresis 2017; 38:738-746. [PMID: 27859480 PMCID: PMC5500191 DOI: 10.1002/elps.201600381] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 10/12/2016] [Accepted: 10/17/2016] [Indexed: 12/21/2022]
Abstract
Phospholipid bilayer nanodiscs composed of 1,2-dimyristoyl-sn-glycero-3-phosphocholine and synthetic maleic acid-styrene copolymer belts have been introduced as a pseudostationary phase (PSP) in electrokinetic chromatography and demonstrated good performance. The nanodiscs provide a suitable migration range and high theoretical plate counts. Using this nanodisc pseudostationary phase, the affinity of the bilayer structure for probe solutes was determined and characterized. Good correlation is observed between retention factors and octanol water partition coefficients for particular categories of solutes, but the general correlation is weak primarily because the nanodiscs show stronger affinity than octanol for hydrogen bond donors. This suggests that a more appropriate application of this technology is to measure and characterize interactions between solutes and lipid bilayers directly. Linear solvation energy relationship analysis of the nanodisc-solute interactions in this study demonstrates that the nanodiscs provide a solvation environment with low cohesivity and weak hydrogen bond donating ability, and provide relatively strong hydrogen bond acceptor strength.
Collapse
Affiliation(s)
- William M Penny
- Department of Chemistry and Biochemistry, University of Montana, Missoula, MT, USA
| | - Harmen B Steele
- Department of Chemistry and Biochemistry, University of Montana, Missoula, MT, USA
| | - J B Alexander Ross
- Department of Chemistry and Biochemistry, University of Montana, Missoula, MT, USA
| | - Christopher P Palmer
- Department of Chemistry and Biochemistry, University of Montana, Missoula, MT, USA
| |
Collapse
|
6
|
Morikawa G, Suzuka C, Shoji A, Shibusawa Y, Yanagida A. High-throughput determination of octanol/water partition coefficients using a shake-flask method and novel two-phase solvent system. J Pharm Biomed Anal 2015; 117:338-44. [PMID: 26422471 DOI: 10.1016/j.jpba.2015.09.019] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 09/14/2015] [Accepted: 09/16/2015] [Indexed: 11/25/2022]
Abstract
A high-throughput method for determining the octanol/water partition coefficient (P(o/w)) of a large variety of compounds exhibiting a wide range in hydrophobicity was established. The method combines a simple shake-flask method with a novel two-phase solvent system comprising an acetonitrile-phosphate buffer (0.1 M, pH 7.4)-1-octanol (25:25:4, v/v/v; AN system). The AN system partition coefficients (K(AN)) of 51 standard compounds for which log P(o/w) (at pH 7.4; log D) values had been reported were determined by single two-phase partitioning in test tubes, followed by measurement of the solute concentration in both phases using an automatic flow injection-ultraviolet detection system. The log K(AN) values were closely related to reported log D values, and the relationship could be expressed by the following linear regression equation: log D=2.8630 log K(AN) -0.1497(n=51). The relationship reveals that log D values (+8 to -8) for a large variety of highly hydrophobic and/or hydrophilic compounds can be estimated indirectly from the narrow range of log K(AN) values (+3 to -3) determined using the present method. Furthermore, log K(AN) values for highly polar compounds for which no log D values have been reported, such as amino acids, peptides, proteins, nucleosides, and nucleotides, can be estimated using the present method. The wide-ranging log D values (+5.9 to -7.5) of these molecules were estimated for the first time from their log K(AN) values and the above regression equation.
Collapse
Affiliation(s)
- Go Morikawa
- Division of Pharmaceutical and Biomedical Analysis, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
| | - Chihiro Suzuka
- Division of Pharmaceutical and Biomedical Analysis, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
| | - Atsushi Shoji
- Division of Pharmaceutical and Biomedical Analysis, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
| | - Yoichi Shibusawa
- Division of Pharmaceutical and Biomedical Analysis, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
| | - Akio Yanagida
- Division of Pharmaceutical and Biomedical Analysis, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan.
| |
Collapse
|
7
|
Jin X, Leclercq L, Cottet H. Determination of polymer log D distributions by micellar and microemulsion electrokinetic chromatography. J Chromatogr A 2014; 1318:244-50. [PMID: 24209298 DOI: 10.1016/j.chroma.2013.10.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 10/01/2013] [Accepted: 10/04/2013] [Indexed: 10/26/2022]
Abstract
The characterization of the hydrophobicity of polymer compounds in solution remains a challenging issue of importance, especially for biomedical or pharmaceutical applications. To our knowledge, there is no data of polymer hydrophobicity (log D) in the literature. In this work, for the first time, the log D distributions of cationic polymers were characterized using micellar or microemulsion electrokinetic chromatography at physiological pH. The log D distributions of the polymer samples were obtained from the electrophoretic/chromatographic retardation of the polymer derivatives in presence of neutral micelles (or neutral microemulsion), using small cationic molecules for calibration. Separating electrolytes were based on a TRIS–chloride buffer containing a neutral surfactant (polyoxyethyleneglycoldodecyl ether) for the formation of micelles (in water) or microemulsion (in water/n-pentanol mixture).The log D distributions obtained at pH 7.4 using this method were in good agreement with the chemical structures of cationic polypeptides: poly(lys, phe) 1:1 > poly(lys, tyr) 1:1 > poly(lys, trp) 4:1 > poly(lys, ser)3:1 > poly(l-lysine), where x:y represents the molar ratio of each amino acid in the copolymer. Weight average octanol–water log D values and the dispersion of the log D distribution were also defined and determined for each polymer sample.
Collapse
|
8
|
Dancik Y, Anissimov YG, Jepps OG, Roberts MS. Convective transport of highly plasma protein bound drugs facilitates direct penetration into deep tissues after topical application. Br J Clin Pharmacol 2012; 73:564-78. [PMID: 21999217 DOI: 10.1111/j.1365-2125.2011.04128.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT Many products are applied to human skin for local effects in deeper tissues. Animal studies suggest that deep dermal and/or subcutaneous delivery may be facilitated by both dermal diffusion and transport via the cutaneous vasculature. However, the relationship between the extent and pathways of penetration, drug physicochemical properties and deeper tissue physiology is not well understood. WHAT THIS STUDY ADDS We have used a physiologically based pharmacokinetic model to analyze published human cutaneous microdialysis data, complemented by our own in vitro skin penetration studies. We found that convective blood, lymphatic and interstitial flow led to significant deep tissue concentrations for drugs that are highly plasma protein bound. In such cases, deeper tissue concentrations will occur earlier and may be several orders of magnitude greater than predicted by passive dermal diffusion alone. AIMS To relate the varying dermal, subcutaneous and muscle microdialysate concentrations found in man after topical application to the nature of the drug applied and to the underlying physiology. METHODS We developed a physiologically based pharmacokinetic model in which transport to deeper tissues was determined by tissue diffusion, blood, lymphatic and intersitial flow transport and drug properties. The model was applied to interpret published human microdialysis data, estimated in vitro dermal diffusion and protein binding affinity of drugs that have been previously applied topically in vivo and measured in deep cutaneous tissues over time. RESULTS Deeper tissue microdialysis concentrations for various drugs in vivo vary widely. Here, we show that carriage by the blood to the deeper tissues below topical application sites facilitates the transport of highly plasma protein bound drugs that penetrate the skin, leading to rapid and significant concentrations in those tissues. Hence, the fractional concentration for the highly plasma protein bound diclofenac in deeper tissues is 0.79 times that in a probe 4.5 mm below a superficial probe whereas the corresponding fractional concentration for the poorly protein bound nicotine is 0.02. Their corresponding estimated in vivo lag times for appearance of the drugs in the deeper probes were 1.1 min for diclofenac and 30 min for nicotine. CONCLUSIONS Poorly plasma protein bound drugs are mainly transported to deeper tissues after topical application by tissue diffusion whereas the transport of highly plasma protein bound drugs is additionally facilitated by convective blood, lymphatic and interstitial transport to deep tissues.
Collapse
Affiliation(s)
- Yuri Dancik
- Therapeutics Research Centre, School of Medicine, University of Queensland, Princess Alexandra Hospital, Brisbane, QLD 4120, Australia
| | | | | | | |
Collapse
|
9
|
Zamek-Gliszczynski MJ, Sprague KE, Espada A, Raub TJ, Morton SM, Manro JR, Molina-Martin M. How Well Do Lipophilicity Parameters, MEEKC Microemulsion Capacity Factor, and Plasma Protein Binding Predict CNS Tissue Binding? J Pharm Sci 2012; 101:1932-40. [DOI: 10.1002/jps.23081] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2011] [Revised: 01/22/2012] [Accepted: 01/25/2012] [Indexed: 11/09/2022]
|
10
|
Jiang X, Xia Z, Deng L, Wei W, Chen J, Xu J, Li H. Evaluation of Accuracy for the Measurement of Octanol–Water Partition Coefficient by MEEKC. Chromatographia 2012. [DOI: 10.1007/s10337-012-2184-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
11
|
Xia Z, Yang J, Li L, Yang F, Jiang X. Determination of Octanol–Water Partition Coefficients by MEEKC Based on Peak-Shift Assay. Chromatographia 2010. [DOI: 10.1365/s10337-010-1666-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
12
|
Henchoz Y, Romand S, Schappler J, Rudaz S, Veuthey JL, Carrupt PA. High-throughput log P determination by MEEKC coupled with UV and MS detections. Electrophoresis 2010; 31:952-64. [DOI: 10.1002/elps.200900540] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
13
|
Poole CF, Atapattu SN, Poole SK, Bell AK. Determination of solute descriptors by chromatographic methods. Anal Chim Acta 2009; 652:32-53. [DOI: 10.1016/j.aca.2009.04.038] [Citation(s) in RCA: 189] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2009] [Revised: 04/25/2009] [Accepted: 04/28/2009] [Indexed: 11/24/2022]
|
14
|
Nishimura I, Hirano A, Yamashita T, Fukami T. Improvement of the high-speed logD assay using an injection marker for the water plug aspiration/injection method. J Chromatogr A 2009; 1216:2984-8. [DOI: 10.1016/j.chroma.2009.02.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2008] [Revised: 01/26/2009] [Accepted: 02/03/2009] [Indexed: 11/16/2022]
|
15
|
Henchoz Y, Bard B, Guillarme D, Carrupt PA, Veuthey JL, Martel S. Analytical tools for the physicochemical profiling of drug candidates to predict absorption/distribution. Anal Bioanal Chem 2009; 394:707-29. [DOI: 10.1007/s00216-009-2634-y] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2008] [Revised: 01/16/2009] [Accepted: 01/19/2009] [Indexed: 10/21/2022]
|
16
|
Cao Y, Gong W, Li N, Yin C, Wang Y. Comparison of microemulsion electrokinetic chromatography with high-performance liquid chromatography for fingerprint analysis of resina draconis. Anal Bioanal Chem 2008; 392:1003-10. [PMID: 18758761 DOI: 10.1007/s00216-008-2337-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2008] [Revised: 07/06/2008] [Accepted: 08/04/2008] [Indexed: 10/21/2022]
Abstract
Microemulsion electrokinetic chromatography (MEEKC) has been developed for fingerprint analysis of resina draconis, a substitute for sanguis draconis in the Chinese market. The microemulsion as the running buffer was made up of 3.3% (w/v) sodium dodecyl sulfate (SDS), 6.6% (w/v) n-butanol, 0.8% (w/v) n-octane, and 10 mmol/L sodium tetraborate buffer (pH 9.2), which was also used as the solvent for ultrasonic extraction of both water- and fat-soluble compounds in the traditional Chinese medicine samples. Four batches of resina draconis obtained from different pharmaceutical factories located in different geographic regions were used to establish the electrophoretic fingerprint. MEEKC was performed using a Beckman PACE/MDQ system equipped with a diode-array detector and with monitoring at 280 nm. The fingerprint of resina draconis comprised 27 common peaks within 100 min. The relative standard deviations of the relative migration time of these common peaks were less than 2.1%. Through repetitive injection of the sample solution six times in 24 h, all relative standard deviations of the migration time and peak area of loureirin A and loureirin B were less than 2.5 and 3.8%, which demonstrated that the method had good stability and reproducibility. The relative peak areas of these common peaks in the electropherograms of four batches of resina draconis were processed with two mathematical methods, the correlation coefficient and the interangle cosine, to valuate the similarity. The values of the similarity degree of all samples were more than 0.91, which showed resina draconis samples from different origins were consistent. On the other hand, high-performance liquid chromatography (HPLC) coupled with photodiode-array detection was also applied to establish the fingerprint of resina draconis. The samples were separated with a LiChrospher C(18) column using acetonitrile (solvent A) and water containing 0.1% H(3)PO(4) (solvent B) as the mobile phase in linear gradient elution mode at a flow rate of 0.6 mL/min and detection was at 280 nm. There were only 20 common peaks in the HPLC fingerprint, and the values of the similarity degree of all samples were also more than 0.91. Though the similarity results of fingerprint analysis seemed to be the same, MEEKC resulted in more common peaks and higher separation efficiency for a variety of polarities of the components than HPLC. So, MEEKC was more suitable for development of the fingerprint of resina draconis.
Collapse
Affiliation(s)
- Yuhua Cao
- School of Chemical and Material Engineering, Jiangnan University, Wuxi, 214122, China.
| | | | | | | | | |
Collapse
|
17
|
Wan Ibrahim WA, Hermawan D, Hasan MN, Aboul Enein HY, Sanagi MM. Rapid Estimation of Octanol–Water Partition Coefficient for Triazole Fungicides by MEKC with Sodium Deoxycholate as Surfactant. Chromatographia 2008. [DOI: 10.1365/s10337-008-0721-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
18
|
Capillary electrophoresis for pharmaceutical analysis. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2008. [PMID: 18392572 DOI: 10.1007/978-1-59745-376-9_10] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
This chapter describes the application of capillary electrophoresis (CE) to pharmaceutical analysis. The areas of pharmaceutical analysis covered are enantiomer separation, analysis of small molecules such as amino acids or drug counter-ions, pharmaceutical assay, related substances determinations, and physiochemical measurements such as log P and pKa of compounds. The different electrophoretic modes available and their advantages for pharmaceutical analysis are described. Recent applications of CE for each subject area are tabulated with electrolyte details. Information on electrolyte choice and method optimization to obtain optimal separations is included.
Collapse
|
19
|
Morisada S, Suzuki H, Emura S, Hirokawa Y, Nakano Y. Temperature-swing adsorption of aromatic compounds in water using polyampholyte gel. ADSORPTION 2008. [DOI: 10.1007/s10450-008-9112-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
20
|
Martel S, Guillarme D, Henchoz Y, Galland A, Veuthey J, Rudaz S, Carrupt P. Chromatographic Approaches for Measuring Log
P. ACTA ACUST UNITED AC 2008. [DOI: 10.1002/9783527621286.ch13] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
21
|
Quantitative structure–retention (property) relationships in micellar electrokinetic chromatography. J Chromatogr A 2008; 1182:1-24. [DOI: 10.1016/j.chroma.2007.12.080] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2007] [Revised: 11/24/2007] [Accepted: 12/31/2007] [Indexed: 10/22/2022]
|
22
|
Xia Z, Jiang X, Mu X, Chen H. Improvement of microemulsion electrokinetic chromatography for measuring octanol–water partition coefficients. Electrophoresis 2008; 29:835-42. [DOI: 10.1002/elps.200700104] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
23
|
Kulkarni S, Shearrow AM, Malik A. Sol–gel immobilized short-chain poly(ethylene glycol) coating for capillary microextraction of underivatized polar analytes. J Chromatogr A 2007; 1174:50-62. [DOI: 10.1016/j.chroma.2007.10.082] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2007] [Revised: 10/23/2007] [Accepted: 10/24/2007] [Indexed: 10/22/2022]
|
24
|
Dohta Y, Yamashita T, Horiike S, Nakamura T, Fukami T. A system for LogD screening of 96-well plates using a water-plug aspiration/injection method combined with high-performance liquid chromatography-mass spectrometry. Anal Chem 2007; 79:8312-5. [PMID: 17910417 DOI: 10.1021/ac0709798] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A system for screening of the octanol/water distribution coefficient (LogD) using automatic sampling of 96-well plates was developed. The high-speed assay for LogD (HSLogD) screening uses a water-plug aspiration/injection method combined with high-performance liquid chromatography-mass spectrometry (HPLC-MS). The method is useful for LogD analysis of highly hydrophobic compounds, where the concentration of the compound in the octanol phase is much higher than that in the water phase. In the case of LogD analyses, the conventional shake-flask method has been widely used, but it is difficult to increase the throughput of the shake-flask method because the lower water phase is carefully separated by manual separation without contamination of the upper octanol phase. We attempted to develop an automatic sampling method instead of manual separation to increase the throughput of the measurement. In initial attempts at automatic sampling, contamination of the octanol phase occurred when sampling of the water phase was made. This was because the octanol phase entered the sampling needle as it passed through to the lower water phase. This contamination was prevented by taking up a few microliters of water into the needle as a plug before sampling of the water phase (the water-plug aspiration/injection method). LogD values of some common drugs measured using the HSLogD agreed with reported LogD values (0 < LogD < 5).
Collapse
Affiliation(s)
- Yukifumi Dohta
- Tsukuba Research Institute, Banyu Pharmaceutical Co., Ltd., 3 Okubo, Tsukuba, Ibaraki 300-2611, Japan
| | | | | | | | | |
Collapse
|
25
|
Shoji A, Yanagida A, Shindo H, Ito Y, Shibusawa Y. Counter-current chromatographic estimation of hydrophobicity of Z-(cis) and E-(trans) enalapril and kinetics of cis/trans isomerization. J Chromatogr A 2007; 1157:101-7. [PMID: 17467722 DOI: 10.1016/j.chroma.2007.04.027] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2006] [Revised: 04/13/2007] [Accepted: 04/13/2007] [Indexed: 10/23/2022]
Abstract
The kinetics of Z-(cis)/E-(trans) isomerization of enalapril was investigated by reversed phase high-performance liquid chromatography (RP-HPLC) using a monolith ODS column under a series of different temperature and pH conditions. At a neutral pH 7, the rate (k(obs)) of Z-(cis)/E-(trans) isomerization of enalapril at 4 degrees C (9.4 x 10(-3)min(-1)) is much lower than at 23 degrees C (1.8 x 10(-1)min(-1)), while the fractional concentration of Z-(cis) isomer is always higher than that of E-(trans) isomer in the pH range 2-7. The fractional concentration of the E-(trans) isomer becomes a maximum (about 40%) in the pH range 3-6, where enalapril exists as a zwitterion. The hydrophobicity (logP(O/W)) of both isomers was estimated by high-speed counter-current chromatography (HSCCC). Normal phase HSCCC separation using a tert-butyl methyl ether-acetonitrile-20mM potassium phosphate buffer (pH 5) two-phase solvent system (2:2:3, v/v/v) at 4 degrees C was effective in partially separating the isomers, and the partition coefficient (K) of each isomer was directly calculated from the retention volume (V(R)). The logP(O/W) values of Z-(cis) and E-(trans) isomers were -0.46 and -0.65, respectively.
Collapse
Affiliation(s)
- Atsushi Shoji
- Division of Structural Biology and Analytical Science, School of Pharmacy, Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
| | | | | | | | | |
Collapse
|
26
|
Affiliation(s)
- Roman Kaliszan
- Department of Biopharmaceutics and Pharmacodynamics, Medical University of Gdańsk, Gen. J. Hallera 107, 80416 Gdańsk, Poland.
| |
Collapse
|
27
|
Altria K, Marsh A, Sänger-van de Griend C. Capillary electrophoresis for the analysis of small-molecule pharmaceuticals. Electrophoresis 2006; 27:2263-82. [PMID: 16786477 DOI: 10.1002/elps.200600030] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
This paper reviews the application of CE to the analysis of small-molecule pharmaceuticals. The areas of pharmaceutical analysis covered are enantiomer separation, the analysis of small molecules such as amino acids or drug counter-ions, pharmaceutical assay, determination of related substances and physicochemical measurements such as log P and pK(a) of compounds. The different electrophoretic modes available and their advantages for pharmaceutical analysis are described. Recent applications of CE for each subject area are tabulated with electrolyte details.
Collapse
Affiliation(s)
- Kevin Altria
- GlaxoSmithKline Research & Development, Harlow, Essex, UK.
| | | | | |
Collapse
|
28
|
Abstract
Compared to MEKC, the presence of a water-immiscible oil phase in the microemulsion droplets of microemulsion EKC (MEEKC) gives rise to some special properties, such as enhanced solubilization capacity and enlarged migration window, which could allow for the improved separation of various hydrophobic and hydrophilic compounds, with reduced sample pretreatment steps, unique selectivities and/or higher efficiencies. Typically, stable and optically clear oil-in-water microemulsions containing a surfactant (SDS), oil (octane or heptane), and cosurfactant (1-butanol) in phosphate buffer are employed as separation media in conventional MEEKC. However, in recent years, the applicability of reverse MEEKC (water-in-oil microemulsions) has also been demonstrated, such as for the enhanced separation of highly hydrophobic substances. Also, during the past few years, the development and application of MEEKC for the separation of chiral molecules has been expanded, based on the use of enantioselective microemulsions that contained a chiral surfactant or chiral alcohol. On the other hand, the application of MEEKC for the characterization of the lipophilicity of chemical substances remains an active and important area of research, such as the use of multiplex MEEKC for the high-throughput determination of partition coefficients (log P values) of pharmaceutical compounds. In this review, recent applications of MEEKC (covering the period from 2003 to 2005) are reported. Emphases are placed on the discussion of MEEKC in the separation of chiral molecules and highly hydrophobic substances, as well as in the determination of partition coefficients, followed by a survey of recent applications of MEEKC in the analysis of pharmaceuticals, cosmetics and health-care products, biological and environmental compounds, plant materials, and foods.
Collapse
Affiliation(s)
- Carmen W Huie
- Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong, China.
| |
Collapse
|
29
|
West C, Lesellier E. Effects of modifiers in subcritical fluid chromatography on retention with porous graphitic carbon. J Chromatogr A 2005; 1087:64-76. [PMID: 16130699 DOI: 10.1016/j.chroma.2005.03.104] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The effect of different modifiers in subcritical fluid chromatography (SubFC) on interactions between solute and porous graphitic carbon (PGC) and between solute and carbon dioxide-modifier mobile phases was studied by the use of linear solvation energy relationships (LSERs). This study was performed to allow efficient optimization of the composition of the carbon dioxide-modifier mobile phase in regard of the chemical nature of the solutes to be separated. With all modifiers tested (methanol, ethanol, n-propanol, isopropanol, acetonitrile, tetrahydrofuran and hexane), the solute/stationary phase interactions are greater than the solute/mobile phase ones. Dispersion interactions and charge transfer between electron donor solute and electron acceptor PGC mainly explain the retention on this surface, whatever the modifier. These interactions are quite constant over the range of modifier percentage studied (5-40%). For acidic compounds, the retention variation is mainly related to the change in the basic character of mobile and stationary phase due to the variation of modifier percentage. Changes in eluting strength are mostly related to adsorption of mobile phase onto the PGC with methanol and acetonitrile, and to the increase of dispersion interactions between the solute and the mobile phase for other modifiers. Relationships between varied selectivities and solvation parameter values have been studied and are discussed in this paper.
Collapse
Affiliation(s)
- C West
- LETIAM, Groupe de Chimie Analytique de Paris Sud (EA 3343), IUT d'Orsay, Plateau du Moulon, 91400 Orsay, France
| | | |
Collapse
|
30
|
Marsh A, Clark B, Broderick M, Power J, Donegan S, Altria K. Recent advances in microemulsion electrokinetic chromatography. Electrophoresis 2005; 25:3970-80. [PMID: 15597422 DOI: 10.1002/elps.200406112] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Microemulsion electrokinetic chromatography (MEEKC) is an electrodriven separation technique. Separations are typically achieved using oil-in-water microemulsions, which are composed of nanometre-sized droplets of oil suspended in aqueous buffer. The oil droplets are coated in surfactant molecules and the system is stabilised by the addition of a short-chain alcohol cosurfactant. The novel use of water-in-oil microemulsions for MEEKC separations has also been investigated recently. This report summarises the different microemulsion types and compositions used to-date and their applications with a focus on recent papers (2002-2004). The effects of key operating variables (pH, surfactant, cosurfactant, oil phase, buffer, additives, temperature, organic modifier) and methodology techniques are described.
Collapse
Affiliation(s)
- Alex Marsh
- GlaxoSmithKline R&D, New Frontiers Science Park South, Harlow, Essex, UK.
| | | | | | | | | | | |
Collapse
|
31
|
Berthod A, Carda-Broch S. Determination of liquid–liquid partition coefficients by separation methods. J Chromatogr A 2004; 1037:3-14. [PMID: 15214657 DOI: 10.1016/j.chroma.2004.01.001] [Citation(s) in RCA: 192] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
By essence, all kinds of chromatographic methods use the partitioning of solutes between a stationary and a mobile phase to separate them. Not surprisingly, separation methods are useful to determine accurately the liquid-liquid distribution constants, commonly called partition coefficient. After briefly recalling the thermodynamics of the partitioning of solutes between two liquid phases, the review lists the different methods of measurement in which chromatography is involved. The shake-flask method is described. The ease of the HPLC method is pointed out with its drawback: the correlation is very sensitive to congeneric effect. Microemulsion electrokinetic capillary electrophoresis has become a fast and reliable method commonly used in industry. Counter-current chromatography (CCC) is a liquid chromatography method that uses a liquid stationary phase. Since the CCC solute retention volumes are only depending on their partition coefficients, it is the method of choice for partition coefficient determination with any liquid system. It is shown that Ko/w, the octanol-water partition coefficients, are obtained by CCC within the -1 < log Ko/w < 4 range, without any correlation or standardization using octanol as the stationary phase. Examples of applications of the knowledge of liquid-liquid partition coefficient in the vast world of solvent extraction and hydrophobicity estimation are presented.
Collapse
Affiliation(s)
- A Berthod
- Laboratoire des Sciences Analytiques, CNRS, Université de Lyon 1, Bat CPE-308, 43 Boulevard du 11 November 1918, 69622 Villeurbanne Cedex, France.
| | | |
Collapse
|
32
|
Daniels CR, Charlton AK, Wold RM, Acree, Jr. WE, Abraham MH. Thermochemical behavior of dissolved carboxylic acid solutes: Solubilities of 3-methylbenzoic acid and 4-chlorobenzoic acid in organic solvents. CAN J CHEM 2003. [DOI: 10.1139/v03-169] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The Abraham general solvation model is used to correlate the solubility behavior of 3-methylbenzoic acid and 4-chlorobenzoic acid in alcohol and ether solvents. The mathematical correlations take the form of [Formula: see text] [Formula: see text] where CS and CW refer to the solute solubility in the organic solvent and water, respectively; CG is a gas-phase concentration; R2 is the solute excess molar refraction; Vx is the McGowan volume of the solute; ΣαH2 and ΣβH2 are measures of the solute hydrogen-bond acidity and hydrogen-bond basicity; πH2 denotes the solute dipolaritypolarizability descriptor; and L(16) is the solute gas-phase dimensionless Ostwald partition coefficient into hexadecane at 298 K. The remaining symbols in the above expressions are known solvent coefficients, which have been determined previously for a large number of gassolvent and watersolvent systems. The Abraham general solvation model was found to describe the experimental solubility data and published literature partitioning data of 3-methylbenzoic acid and 4-chlorobenzoic acid to within overall standard deviations of 0.079 log units and 0.085 log units, respectively. Key words: 3-methylbenzoic acid solubilities, 4-chlorobenzoic acid solubilities, alcohol solvents, partition coefficients, molecular solute descriptors, solubility predictions.
Collapse
|