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Lin PC, Hsieh YH, Liao FF, Chen SH. Determination of free and total levels of phenytoin in human plasma from patients with epilepsy by MEKC: An adequate alternative to HPLC. Electrophoresis 2010; 31:1572-82. [DOI: 10.1002/elps.200900768] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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2
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Pucci V, Raggi MA. Analysis of antiepileptic drugs in biological fluids by means of electrokinetic chromatography. Electrophoresis 2005; 26:767-782. [PMID: 15714570 DOI: 10.1002/elps.200410207] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
An overview of the electrokinetic chromatographic methods for the analysis of antiepileptic drug levels in biological samples is presented. In particular, micellar electrokinetic capillary chromatography is a very suitable method for the determination of these drugs, because it allows a rapid, selective, and accurate analysis. In addition to the electrokinetic chromatographic studies on the determination of antiepileptic drugs, some information regarding sample pretreatment will also be reported: this is a critical step when the analysis of biological fluids is concerned. The electrokinetic chromatographic methods for the determination of recent antiepileptic drugs (e.g., lamotrigine, levetiracetam) and classical anticonvulsants (e.g., carbamazepine, phenytoin, ethosuximide, valproic acid) will be discussed in depth, and their pharmacological profiles will be briefly described as well.
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Affiliation(s)
- Vincenzo Pucci
- Department of Pharmaceutical Sciences, Faculty of Pharmacy, Alma Mater Studiorum - University of Bologna, Bologna, Italy
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3
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Alsarra IA, Al-Omar M, Belal F. Valproic Acid and sodium valproate: comprehensive profile. PROFILES OF DRUG SUBSTANCES, EXCIPIENTS, AND RELATED METHODOLOGY 2005; 32:209-40. [PMID: 22469088 DOI: 10.1016/s0099-5428(05)32008-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Affiliation(s)
- Ibrahim A Alsarra
- Department of Pharmaceutics, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Kingdom of Saudi Arabia
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4
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Pucci V, Mandrioli R, Raggi MA. Determination of valproic acid (2-propylpentanoic acid) in human plasma by capillary electrophoresis with indirect UV detection. Electrophoresis 2003; 24:2076-2083. [PMID: 12858378 DOI: 10.1002/elps.200305405] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A rapid capillary zone electrophoresis method with indirect UV detection was developed and validated for the determination of valproic acid (VPA) in human plasma. The analyses were carried out under optimized conditions, using a buffer system composed of 15 mM benzoate and 0.5 mM cetyltrimethylammonium bromide at pH 6.0, and 25% v/v methanol; 2-hydroxybutyric acid was selected as the internal standard (IS). The capillary electrophoresis (CE) separation was carried out at a negative potential of 30 kV and the indirect UV detection was operated at 210 +/- 20 nm for all assays. The influence of buffer pH, ionic strength, concentration of electroosmotic flow (EOF) modifier and organic modifier on indirect signal response and migration behavior of the organic acid was investigated. Isolation of VPA from plasma was accomplished by a carefully implemented procedure using methanol as the precipitant agent. Using a high ratio of methanol to plasma for deproteinization (4:1), good absolute recovery of the analyte and satisfactory selectivity was obtained. The calibration line for VPA was linear over the 1-100 microg/mL concentration range. Sensitivity was high; in fact, the limit of detection (LOD) of VPA was 150 ng/mL and 450 ng/mL the limit of quantitation (LOQ). The results obtained analyzing real plasma samples from schizophrenic patients under polytherapy with VPA as well as antipsychotic drugs were satisfactory in terms of precision, accuracy and sensitivity.
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Affiliation(s)
- Vincenzo Pucci
- Department of Pharmaceutical Sciences, University of Bologna, Bologna, Italy
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5
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Ivanova M, Marziali E, Raggi MA, Kenndler E. Microemulsion electrokinetic chromatography for the separation of carbamazepine, oxcarbazepine, and their metabolites. J Sep Sci 2002. [DOI: 10.1002/1615-9314(20021001)25:14<863::aid-jssc863>3.0.co;2-f] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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6
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Franeta JT, Agbaba D, Eric S, Pavkov S, Aleksic M, Vladimirov S. HPLC assay of acetylsalicylic acid, paracetamol, caffeine and phenobarbital in tablets. FARMACO (SOCIETA CHIMICA ITALIANA : 1989) 2002; 57:709-13. [PMID: 12385520 DOI: 10.1016/s0014-827x(02)01265-x] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
This paper present a HPLC method for simultaneous determination of acetylsalicylic acid, paracetamol, caffeine and phenobarbital in tablets, using chromatographic system consisting a Bio Rad 18 01 solvent pump, Rheodine 71 25 injector and Bio Rad 18 01 UV-Vis Detector. Separation was achieved using Bio SiL HL C18, 5 microm, 250 x 4.6 mm column. Mixture of acetonitrile-water (25:75 v/v) adjusted to pH 2.5 with phosphoric acid was used as a mobile phase at a flow rate of 2.0 ml min(-1). UV detection was at 207 nm range 0.01 AUFS. Under the same conditions it was possible to determine the level of salicylic acid. The chromatographic parameters such as retention times, capacity factor, peak asymmetry, selectivity factor and resolution factor was determined. The validation parameters: linearity (r > 0.998), intra-day precision (RSD: 0.36-1.89%) and inter-day precision (RSD: 0.58-2.18%), sensitivity (LOD: 9 x 10(-5)-1.7 x 10(-4) mg ml(-1) and LOQ: 2.5 x 10(-4)-5.6 x 10(-4) mg ml(-1)), accuracy (recoveries: 98.35-99.14%) and reproducibility (recovery values: 98.74-102.08% for acetylsalicylic acid, 99.93-102.11% for paracetamol, 98.25-102.12% for caffeine and 98.15-102.3% for phenobarbital) (RSD: 1.21-1.85%) were found to be satisfactory. The proposed HPLC method has been applied for the determination of acetylsalicylic acid, paracetamol, caffeine and phenobarbital in Malophenum tablets. The obtained RSD values were within 0.99-1.21%. The developed method is rapid and sensitive and therefore suitable for routine control of these drugs in dosage form.
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Affiliation(s)
- J T Franeta
- Department of Pharmaceutical Chemistry and Drug Analysis, Faculty of Pharmacy, Belgrade, Serbia, Yugoslavia
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7
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Marziali E, Raggi MA, Komarova N, Kenndler E. Octakis-6-sulfato-gamma-cyclodextrin as additive for capillary electrokinetic chromatography of dibenzoazepines: carbamazepine, oxcarbamazepine and their metabolites. Electrophoresis 2002; 23:3020-6. [PMID: 12207311 DOI: 10.1002/1522-2683(200209)23:17<3020::aid-elps3020>3.0.co;2-#] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Single isomer octakis-(2,3-dihydroxy-)6-sulfato-gamma-cyclodextrin used as pseudostationary phase of the background electrolyte interacts with dibenzo[b,f]azepines (consisting of a condensed 3-ring system) and forms negatively charged complexes. Hydroxygroups in position 2 and 3 at carbamazepine increase the extent of interaction, whereas substitution by oxygen at position 10 and/or 11 reduces it. The complex constants for the analytes are ranging from few tens L/mol (10-hydroxycarbamazepine, 10,11-dihydroxycarbamazepine, 10,11-epoxycarbamazepine, oxcarbazepine) to several hundreds L/mol (carbamazepine, 2-hydroxycarbamazepine, 3-hydroxycarbamazepine), and are much larger than those of the analytes with octakis-(2,3-dimethyl-)-6-sulfato-gamma-cyclodextrin. Full enantiomeric separation of the chiral metabolites of carbamazepine and oxcarbazepine is obtained at octakis-(2,3-dihydroxy-)-6-sulfato-gamma-cyclodextrin concentrations of about 10 mM (3 mM borate buffer, pH 8.5). Compared to heptakis-6-sulfato-beta-cyclodextrin, selectivity differs and stereoselectivity is more pronounced.
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Affiliation(s)
- Ettore Marziali
- Institute for Analytical Chemistry, University of Vienna, Vienna, Austria
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8
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Raggi MA, Pucci V, Maurizio A, Muzikar J, Kenndler E. Separation of carbamazepine and five metabolites, and analysis in human plasma by micellar electrokinetic capillary chromatography. J Chromatogr B Analyt Technol Biomed Life Sci 2002; 770:217-25. [PMID: 12013229 DOI: 10.1016/s0378-4347(01)00524-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A rapid and feasible method was developed for the analysis of carbamazepine and its five metabolites (10,11-dihydro-10,11-epoxycarbamazepine, 10,11-dihydro-10,11-dihydroxycarbamazepine, 10,11-dihydro-10-hydroxycarbamazepine, 2-hydroxycarbamazepine and 3-hydroxycarbamazepine) in human plasma. Separation of the analytes is based on micellar electrokinetic chromatography, in untreated fused-silica capillary (48.5/40.0 cm length, 50 microm I.D.) with phosphate buffer (30 mM, pH 8.00) as background electrolyte, containing 50 mM sodium dodecylsulfate, and methanol (15%, v/v) as organic modifier. Clean up of human plasma samples was carried out by means of a solid-phase extraction procedure, which gave a high extraction yield for all six carbamazepines (>88%). The overall precision of the method gives a mean RSD of about 1.8%. The limit of quantitation for all analytes is < or = 0.30 microg ml(-1), the limit of detection < or = 0.12 microg ml(-1).
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9
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Chollet DF. Determination of antiepileptic drugs in biological material. J Chromatogr B Analyt Technol Biomed Life Sci 2002; 767:191-233. [PMID: 11885851 DOI: 10.1016/s0378-4347(01)00502-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Current analytical methodologies applied to the determination of antiepileptic drugs in biological material are reviewed. The role of chromatographic techniques is emphasized. Special attention is focused on new chemical entities as well as current trends such as high-speed liquid chromatographic techniques, hyphenated techniques and electrochromatography techniques. A review with 542 references.
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Affiliation(s)
- Daniel F Chollet
- Covance Central Laboratory Services SA, Drug Monitoring Department, Meyrin/Geneva, Switzerland.
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10
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Hefnawy MM. Micellar electrokinetic capillary chromatography determination of +S and -R arotinolol in serum using UV detection and solid phase extraction. Chirality 2002; 14:67-71. [PMID: 11748803 DOI: 10.1002/chir.888] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A method for the simultaneous determination of +S and -R arotinolol in serum by micellar electrokinetic capillary chromatography is described. Stereoselective resolution of the arotinolol enantiomers was achieved using 5 mM sodium taurocholate in 10 mM sodium dihydrogen phosphate buffer of pH 2.5. A 72-cm uncoated fused-silica capillary at a constant voltage of 15 kV was used for the analysis. The analytes of interest were extracted from serum using solid phase extraction. An octadecyl cartridge gave good recoveries in excess of 87% for both +S and -R arotinolol without any interference. The calibration curves were linear over the range of 50-500 ng ml(-1) with +S propranolol as the internal standard and the coefficient of determination was greater than 0.999 (n = 3). The limit of quantitation was 50 ng ml(-1) for each enantiomer and the detection limit using 1 ml serum and a UV detection set et 220 nm was 25 ng ml(-1) (S/N = 2). Precision and accuracy of the method were in the range 0.8-2.7% and 1.2-6.4%, respectively, for +S arotinolol and 1.1-3.9% and 2.2-6.5%, respectively, for -R arotinolol.
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Affiliation(s)
- Mohammed M Hefnawy
- Department of Analytical Chemistry, Faculty of Pharmacy, University of Mansoura, Mansoura, 35516, Egypt
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11
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Thormann W, Theurillat R, Wind M, Kuldvee R. Therapeutic drug monitoring of antiepileptics by capillary electrophoresis. Characterization of assays via analysis of quality control sera containing 14 analytes. J Chromatogr A 2001; 924:429-37. [PMID: 11521893 DOI: 10.1016/s0021-9673(01)00854-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Quality assurance is an important aspect in therapeutic drug monitoring (TDM). Capillary electrophoresis (CE) assays for determination of (i) ethosuximide via direct injection of serum or plasma, (ii) lamotrigine after protein precipitation by acetonitrile and analysis of an aliquot of the acidified supernatant, and (iii) carbamazepine and carbamazepine-10,11-epoxide after solute extraction followed by analysis of the reconstituted extract are characterized via analysis of a large number of commercial quality control sera containing up to 14 analytes (9 of them are anticonvulsants) in sub-therapeutic, therapeutic and toxicologic concentration levels. CE data obtained in single determinations are shown to compare well with the spike values and the mean of data determined in other laboratories using immunoassays and/or high-performance liquid chromatography, values that are reported by the external quality control scheme. Carbamazepine and ethosuximide drug levels are also shown to agree well with those determined in our departmental drug assay laboratory using automated immunoassays. The presented data reveal the effectiveness of assay assessment via analysis of quality control sera and confirm the robustness of the assays for TDM in a routine setting.
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Affiliation(s)
- W Thormann
- Department of Clinical Pharmacology, University of Berne, Switzerland.
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12
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Kuldvee R, Thormann W. Determination of carbamazepine and carbamazepine-10,11-epoxide in human serum and plasma by micellar electrokinetic capillary chromatography in the absence of electroosmosis. Electrophoresis 2001; 22:1345-55. [PMID: 11379957 DOI: 10.1002/1522-2683(200105)22:7<1345::aid-elps1345>3.0.co;2-i] [Citation(s) in RCA: 19] [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
Therapeutic drug monitoring of carbamazepine (CBZ), a widely used antiepileptic drug, is required for optimization of pharmacotherapy with this drug and for assessment of the patient's compliance to therapy. The suitability of employing micellar electrokinetic capillary chromatography (MEKC) in the absence of electroosmosis for the determination of CBZ and its main metabolite carbamazepine-10,11-epoxide (CBZE) in extracts of human serum and plasma is reported. Using micelles formed by dodecyl sulfate, analyses performed in untreated fused-silica capillaries at acidic pH and in commercially available coated capillaries under application of reversed polarity are compared. Uncoated and polyvinyl alcohol coated capillaries proved to be unsuitable for this purpose, whereas capillaries coated with linear polyacrylamide and N-acryloylaminoethoxyethanol and operated at pH 7.6 are shown to provide high-quality and reliable data on a short time scale. Assay performance is discussed via statistical analysis of the data produced from a set of quality control sera that contain up to 14 different drugs and via analysis of patient samples. Intraday and interday imprecision data for concentrations between 4.0 and 84 microM are demonstrated to be < 10%. Run times are shown to be < 50% compared to those observed in conventional MEKC at alkaline pH (i.e., in the presence of electroosmosis).
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Affiliation(s)
- R Kuldvee
- Department of Clinical Pharmacology, University of Bern, Switzerland
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13
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Franeta JT, Agbaba DD, Eric SM, Pavkov SP, Vladimirov SD, Aleksic MB. Quantitative analysis of analgoantipyretics in dosage form using planar chromatography. J Pharm Biomed Anal 2001; 24:1169-73. [PMID: 11248516 DOI: 10.1016/s0731-7085(00)00579-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In the therapy of pain of weaker genesis, frequently used drugs usually represent a mix of analgoantipyretics of different chemical structures, mostly derivatives of salicylic acid, pyrazolone and p-aminophenol as well as derivatives of propionic and acetylsalicylic acid. For the determination of these drugs, different chromatographic methods have been applied, mostly HPLC, due to the the lower polarity (pyrazolones derivatives) and thermolability, as well as nonvolatility of compounds investigated. TLC method, considering advantages which include simplicity, reasonable sensitivity, rapidity, excellent resolving power and low cost has been successfully explored for the determination of analgoantipyretic compounds. The aim of this work was to develop a simple and rapid HPTLC method for the determination of acetylsalicylic acid, paracetamol, caffeine and phenobarbitone in dosage form. The determination of analgoantipyretics were performed on pre-coated HPTLC silica gel plates (10 x 20 cm(2)) by development in the mobile phase dichlormethane-ethyl acetate-cyclohexane-isopropanol-0.1 M HCL-formic acid (9:8:3:1.5:0.2:0.2 v/v/v/v/v/v). Migration distances (68.6+0.2 mm, 54.1+0.1 mm, 36.4+0.14 mm and 85.9+0.11 mm for acetylsalicylic acid, paracetamol, caffeine and phenobarbitone, respectively) with low RSD values (0.13--0.39%) showed a satisfactory reproductivity of the chromatographic system. TLC scanner was used for direct evaluation of the chromatograms in the reflectance/absorbance mode. Established calibration curves (r>0.999), precision (0.3--1.02%) and detection limits, as well as recovery values (96.51--98.1%) were validated and found to be satisfactory. The method was found to be reproducible and convenient for the quantitative analysis of compounds investigated in their dosage forms.
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Affiliation(s)
- J T Franeta
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, PO Box 146, Vojvode Stepe 450, 11000 Belgrade, Serbia, Yugoslavia
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14
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Bereczki A, Horváth V, Horvai G. Immunoassay-based determination of phenobarbital using size-exclusion chromatography. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 2000; 749:215-23. [PMID: 11145058 DOI: 10.1016/s0378-4347(00)00409-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The measurement of the anti-epileptic drug phenobarbital from serum samples combining immunoassay and size-exclusion chromatography is presented. The immunoreaction is based on the competitive binding of the analyte (unlabelled phenobarbital) and the fluorescent-labelled phenobarbital to anti-phenobarbital antibodies. Mixing of the reagents and the immunoreaction takes place in a flow system. The products are separated on-line on a short gel chromatographic column and the fluorescence intensity of the marker is measured. The calibration curve shows good linearity in the range 5-80 microg/ml, corresponding to therapeutically relevant serum levels. Intra-day precision values are between 7.32 and 9.48%; the accuracy is between 0.97 and 9.43%. Inter-day precision and accuracy measured on 6 different days fall between 5.38 and 10.05% and -8.27 and -4.97%, respectively. The results obtained with the proposed method show a good correlation with those of other methods (radioimmunoassay and fluorescence polarisation immunoassay) already established in clinical laboratories.
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Affiliation(s)
- A Bereczki
- Institute of General and Analytical Chemistry, Budapest University of Technology and Economics, Hungary
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15
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Boone CM, Waterval JC, Lingeman H, Ensing K, Underberg WJ. Capillary electrophoresis as a versatile tool for the bioanalysis of drugs--a review. J Pharm Biomed Anal 1999; 20:831-63. [PMID: 10746954 DOI: 10.1016/s0731-7085(99)00088-6] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
This review article presents an overview of current research on the use of capillary electrophoretic techniques for the analysis of drugs in biological matrices. The principles of capillary electrophoresis and its various separation and detection modes are briefly discussed. Sample pretreatment methods which have been used for clean-up and concentration are discussed. Finally, an extensive overview of bioanalytical applications is presented. The bioanalyses of more than 200 drugs have been summarised, including the applied sample pretreatment methods and the achieved detection limits.
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Affiliation(s)
- C M Boone
- Department of Analytical Chemistry and Toxicology, University Center for Pharmacy, Groningen, The Netherlands.
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16
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Abstract
A capillary electrophoresis (CE) method with indirect laser-induced fluorescence detection for the analysis of valproic acid in human serum has been explored. The buffer system was optimized with 2.5 mM borate-phosphate at pH 8.4; fluorescein sodium was used to generate background signal at a concentration of 6 microM. Hexanoic acid was selected as internal standard. Serum sample was deproteinized by acetonitrile. Analysis was performed by direct injection of the supernatant. CE separation was carried out at 30 kV and the total analysis time was less than 15 min, including sample treatment and electrophoresis time. No interference from other common anticonvulsant drugs occurred under the experimental conditions used. The interference of human serum matrix was reduced by using a high ratio of acetonitrile to serum (minimum 5:1) for deproteinization. Interference of ionic components in serum could occur, depending on the sample source. The linear range of concentrations for standard drug was between 4.5-144.0 microg/mL (r = 0.9947). The limit of detection was 0.9 microg/mL at S/N > or = 3; the limit of quantitation at S/N > or = 20 was 3 microg/mL. The recoveries of valproic acid spiked into serum were 69.2% and 60.2% for concentration levels of 90 and 54 microg/mL, respectively. This CE method was shown to be successful in the analysis of valproic acid in standard solutions. However, interference from the matrix was observed in the analysis of this compound in serum samples. Additional work should be done to develop a highly selective sample preparation technique.
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Affiliation(s)
- L J Jin
- Department of Chemistry, National University of Singapore, Republic of Singapore
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17
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Kok SJ, Velthorst NH, Gooijer C, Brinkman UA. Analyte identification in capillary electrophoretic separation techniques. Electrophoresis 1998; 19:2753-76. [PMID: 9870373 DOI: 10.1002/elps.1150191604] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A review on applications of on-line hyphenation in capillary electrophoresis and capillary electrochromatography for the identification of migrating analytes is presented. There is an urgent need for unambiguous analyte identification by combining spectral information and observed migration times, because the parameters influencing the migration times and separation efficiencies in these separation techniques are not easily controlled, especially when real samples containing unknown interferences have to be analyzed. The spectrometric techniques covered here are ultraviolet and visible radiation (UV/Vis) absorption, fluorescence including fluorescence line-narrowing spectroscopy, Raman spectroscopy, nuclear magnetic resonance and mass spectrometry. Attention is essentially confined to literature reports in which the extra information provided by the detector is really used for identification purposes, especially in real-life samples, while the interfacing as such and analyte detectabilities in standard solutions are only briefly discussed. This article covers an extensive fraction of the literature published on this topic until the beginning of 1998.
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Affiliation(s)
- S J Kok
- Vrije Universiteit Amsterdam, Department of General and Analytical Chemistry, The Netherlands
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18
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Abstract
Therapeutic drug monitoring is commonly used in both the ambulatory and hospital patient care settings. Routine measurement of concentrations of therapeutic agents in biological fluids is critical for certain drugs to maintain therapeutic benefit with minimizing drug-associated toxicities. Many analytical laboratory techniques are currently available to measure drug concentrations in biological samples. Recently there has been an increased interest in the use of capillary electrophoresis (CE) for measuring concentrations of therapeutic drugs in patient samples. However, while there are numerous reports of CE being used to measure drug concentrations in solution and pharmaceutical dosage forms, there are relatively few reports of the use of CE for measuring therapeutic agents in patient samples. The purpose of this paper is to provide an overview of methods currently used to measure therapeutic drugs in patient samples along with possible future trends for the use of CE in therapeutic drug monitoring.
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Affiliation(s)
- L J Brunner
- College of Pharmacy, The University of Texas at Austin, 78712-1074, USA.
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19
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Taylor RB, Toasaksiri S, Reid RG. A literature assessment of sample pretreatments and limits of detection for capillary electrophoresis of drugs in biological fluids and practical investigation with some antimalarials in plasma. Electrophoresis 1998; 19:2791-7. [PMID: 9870375 DOI: 10.1002/elps.1150191606] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A literature survey on published reports of the determination of drugs in biological fluids shows that all methods of sample pretreatment have been used and that the limits of detection achieved vary widely, ranging from low ngcm(-3) to microgcm(-3). The most widely used injection method was hydrodynamic and, in the majority of cases, whenever low detection limits were achieved, this was a result of preconcentration during the sample pretreatment. Only a small proportion of the reported methods employed electrokinetic injection and utilised the field amplified sample injection (FASI) techniques. An experimental investigation of the alternative hydrodynamic and electrokinetic injection methods for a small set of antimalarial drugs is reported. It was found that electrokinetic injection with FASI from an acetonitrile-water matrix produced dramatic improvements in detection limits. This improvement could not, however, be achieved when the drugs were in plasma using protein precipitation, liquid-liquid extraction or solid phase extraction pretreatment methods. This highlights the importance of sample pretreatment in utilising the potential sensitivity of capillary electrophoresis with electrokinetic injection.
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Affiliation(s)
- R B Taylor
- School of Pharmacy, The Robert Gordon University, Schoolhill, Aberdeen, UK.
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20
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Kataoka Y, Makino K, Oishi R. Capillary electrophoresis for therapeutic drug monitoring of antiepileptics. Electrophoresis 1998; 19:2856-60. [PMID: 9870380 DOI: 10.1002/elps.1150191611] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
We examined the use of capillary electrophoresis for therapeutic drug monitoring of antiepileptic drugs. Micellar electrokinetic capillary chromatography (MEKC) with a diode array detector simultaneously determined concentrations of zonisamide, a new type of antiepileptic drug, and phenobarbital, phenytoin and carbamazepine, typical antiepileptic drugs, in human serum. Zonisamide levels in human serum obtained by MEKC correlated well with levels obtained by high-performance liquid chromatography. The serum levels of phenobarbital, phenytoin and carbamazepine determined by MEKC were almost equal to those obtained by fluorescence polarization immunoassay. The reproducibility of separation and quantification with MEKC for intra- and inter-day assays were appropriate. This MEKC method could provide a simple and efficient therapeutic drug monitoring method for antiepileptic drugs, especially in patients treated with a combination of zonisamide and other antiepileptic drugs. MEKC may be an attractive method for therapeutic drug monitoring, because of its specificity of separation, automation of procedure, ease of method development, low cost, small aqueous buffer amounts, speed of analysis, small injection volume and high environment-directed performance.
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Affiliation(s)
- Y Kataoka
- Department of Hospital Pharmacy, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
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21
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Heo YJ, Lee KJ. Application of micellar electrokinetic capillary chromatography for the determination of benzoic acid and its esters in liquid formula medicines as preservatives. J Pharm Biomed Anal 1998; 17:1371-9. [PMID: 9800656 DOI: 10.1016/s0731-7085(98)00023-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
We described a method for the simultaneous determination of preservatives including benzoic acid, methyl-, ethyl- and propyl-benzoate by micellar electrokinetic capillary chromatography (MECC). The factors affecting the reproducibility in the quantitative analysis of pharmaceuticals by MECC were investigated by varying the running buffer and washing condition in-between runs. Preservatives in liquid formula medicines have been determined by optimum MECC condition using p-hydroxy benzoic acid as an internal standard. The reproducibility of this method was acceptable as a validate method for the quality control of pharmaceuticals (RSD < 2%). Routine quantitative analysis of pharmaceuticals using MECC could be possible with well characterized reproducible procedure.
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Affiliation(s)
- Y J Heo
- College of Pharmacy, Ewha Womans University, Seoul, South Korea
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22
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Tagliaro F, Turrina S, Pisi P, Smith FP, Marigo M. Determination of illicit and/or abused drugs and compounds of forensic interest in biosamples by capillary electrophoretic/electrokinetic methods. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 1998; 713:27-49. [PMID: 9700551 DOI: 10.1016/s0378-4347(97)00485-4] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The application of capillary electrophoresis (CE) methods in forensic toxicology for the determination of illicit and/or misused drugs in biological samples is reviewed in the present paper. Sample pretreatments and direct injection modes used in CE for analysis of drugs in biological fluids are briefly described. Besides, applications of separation methods based on capillary zone electrophoresis or micellar electrokinetic chromatography with UV absorbance detection to (i) analysis of drugs of abuse, (ii) analysis of other drugs and toxicants of potential forensic interest and (iii) for metabolism studies are reviewed. Also, alternative CE methods are briefly discussed, including capillary isotachophoresis and separation on mixed polymer networks. High sensitivity detection methods used for forensic drug analysis in biological samples are then presented, particularly those based on laser induced fluorescence. A glimpse of the first examples of application of CE-mass spectrometry in forensic toxicology is finally given.
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Affiliation(s)
- F Tagliaro
- Institute of Forensic Medicine, University of Verona, Italy
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23
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Härtter S, Jensen B, Hiemke C, Leal M, Weigmann H, Unger K. Micellar electrokinetic capillary chromatography for therapeutic drug monitoring of carbamazepine and its main metabolites. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 1998; 712:253-8. [PMID: 9698248 DOI: 10.1016/s0378-4347(98)00169-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
In carbamazepine (CBZ) therapy the concomitant monitoring of concentrations of CBZ and its metabolites is strictly recommended, primarily to avoid toxic side effects. Currently, clinical routine monitoring of CBZ is accomplished by high-performance liquid chromatography or immunological methods. In this study a micellar electrokinetic capillary chromatographic (MECC) method was developed for routine drug monitoring of CBZ and its main metabolites, carbamazepine 10,11-diol and carbamazepine 10,11-epoxide, in human serum or plasma samples. The MECC method enabled baseline separation of all analytes within 2.5 min. The assay revealed sufficient precision and sensitivity and the results of either an automated HPLC or the MECC chromatography assay were in good agreement (r=-0.97). The maximum deviation for CBZ was 0.26 microM.
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Affiliation(s)
- S Härtter
- Department of Psychiatry, University of Mainz, Germany
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24
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Abstract
Because of the ease of analysis and the high resolution, drug analysis is becoming the best example for the application of capillary electrophoresis. Therapeutic drug monitoring is a specialized area of drug analysis performed in clinical laboratories for patient care. CE offers high resolution and speed with the low operating costs needed in patient care. However, CE has a few limitations, mainly poor detection limits and precision. Simple methods of stacking, which enhance drug detection to overcome the poor sensitivity of CE are stressed. Serum has a unique matrix with a high content of proteins and salts which can have adverse effects on separation by CE. For successful analysis, special maneuvers are employed to decrease these matrix effects. Studies that have addressed the improvement of the precision of CE are summarized. CE offers the possibility of bringing chiral separations into the routine arena.
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Affiliation(s)
- Z K Shihabi
- Pathology Department, Bowman Gray School of Medicine, Wake Forest University, Winston-Salem, NC 27157, USA
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25
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Abstract
This review surveys the use of micelles as separation media in chromatography and electrophoresis. Applications to pharmaceuticals whose molecular masses are relatively small are focused on in this review. In high-performance liquid chromatography (HPLC), chromatography using micelles and reversed-phase stationary phases such as octadecylsilylized silica gel (ODS) columns is known as micellar liquid chromatography (MLC). The main application of MLC to pharmaceutical analysis is the same as in ion-pair chromatography using alkylsulfonate or tetraalkylammonium. In most cases, selectivity is much improved compared with other short alkyl chain ion-pairing agents such as pentanesulfonate or octanesulfonate. Direct plasma/serum injection can be successful in MLC. Separation of small ions is also successful by using gel filtration columns and micellar solutions. In electrophoresis, especially capillary electrophoresis (CE), micelles are used as pseudo-stationary phases in capillary zone electrophoresis (CZE). This mode is called micellar electrokinetic chromatography (MEKC). Most of the drug analysis can be performed by using the MEKC mode because of its wide applicability. Enantiomer separation, separation of amino acids and closely related peptides, separation of very complex mixtures, determination of drugs in biological samples etc. as well as separation of electrically neutral drugs can be successfully achieved by MEKC. Microemulsion electrokinetic chromatography (MEEKC), in which surfactants are also used in forming the microemulsion, is successful for the separation of electrically neutral drugs as in MEKC. This review mainly describes the typical applications of MLC and MEKC for the analysis of pharmaceuticals.
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Affiliation(s)
- H Nishi
- Analytical Research Laboratory, Tanabe Seiyaku Co., Osaka, Japan
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26
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Muijselaar PG, Otsuka K, Terabe S. Micelles as pseudo-stationary phases in micellar electrokinetic chromatography. J Chromatogr A 1997; 780:41-61. [PMID: 9335128 DOI: 10.1016/s0021-9673(97)00632-8] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
This review article describes some general comments on micellar electrokinetic chromatography (MEKC) from the viewpoint of pseudo-stationary phases and presents a compiled list of surfactants used for MEKC, prepared from published papers. We tried to give comments on some typical surfactants from the practical point of view.
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Affiliation(s)
- P G Muijselaar
- Faculty of Science, Himeji Institute of Technology, Hyogo, Japan
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27
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Levêque D, Gailion-Renault C, Monteil H, Jehl F. Capillary electrophoresis for pharmacokinetic studies. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 1997; 697:67-75. [PMID: 9342657 DOI: 10.1016/s0378-4347(97)00335-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Different analytical techniques involving capillary electrophoresis for the determination of drugs and metabolites in biological fluids are described. Pharmacokinetic studies carried out using capillary electrophoresis are presented, as well as the in vitro metabolism investigations. The advantages and the limitations of capillary electrophoresis for pharmacokinetic studies are discussed.
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Affiliation(s)
- D Levêque
- Laboratory of Pharmacokinetics, Institute of Bacteriology, Strasbourg, France
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28
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Lehmann R, Voelter W, Liebich HM. Capillary electrophoresis in clinical chemistry. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 1997; 697:3-35. [PMID: 9342655 DOI: 10.1016/s0378-4347(97)00183-7] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Since its introduction, capillary electrophoresis has diversified, spreading out into different specialized fields covering solutions for almost any analytical questions arising in research laboratories. In the context of clinical chemistry, results must be provided at low costs and in a clinically relevant time frame; however, the attributes which have made capillary electrophoresis such a successful tool in basic research are identical to those attracting clinical laboratories: speed (more efficient, less labor-intensive), low costs (minimal buffer consumption), small sample volume (reduced blood collection volume from patient), increased selectivity (determination of multiple solutes in one run), and versatility (detection of analytes over the wide range of molecular masses and chemical composition). Nevertheless, it should be mentioned that there are still some drawbacks at this stage to be solved in the near future, such as lack of sensitivity for many clinical applications or the constraint to measure in a sequential mode. The aim of this survey is to familiarize clinical chemists, as well as chemists, with a short introduction to capillary electrophoresis, followed by chapters reviewing prominent fields of applications and the latest developments in clinical chemistry.
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Affiliation(s)
- R Lehmann
- Abteilung Innere Medizin IV, Stoffwechselkrankheiten und Klinische Chemie, Medizinische Klinik und Poliklinik der Universität, Tübingen, Germany
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29
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Guzman NA, Park SS, Schaufelberger D, Hernandez L, Paez X, Rada P, Tomlinson AJ, Naylor S. New approaches in clinical chemistry: on-line analyte concentration and microreaction capillary electrophoresis for the determination of drugs, metabolic intermediates, and biopolymers in biological fluids. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 1997; 697:37-66. [PMID: 9342656 DOI: 10.1016/s0378-4347(97)00275-2] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The use of capillary electrophoresis (CE) for clinically relevant assays is attractive since it often presents many advantages over contemporary methods. The small-diameter tubing that holds the separation medium has led to the development of multicapillary instruments, and simultaneous sample analysis. Furthermore, CE is compatible with a wide range of detectors, including UV-Vis, fluorescence, laser-induced fluorescence, electrochemistry, mass spectrometry, radiometric, and more recently nuclear magnetic resonance, and laser-induced circular dichroism systems. Selection of an appropriate detector can yield highly specific analyte detection with good mass sensitivity. Another attractive feature of CE is the low consumption of sample and reagents. However, it is paradoxical that this advantage also leads to severe limitation, namely poor concentration sensitivity. Often high analyte concentrations are required in order to have injection of sufficient material for detection. In this regard, a series of devices that are broadly termed 'analyte concentrators' have been developed for analyte preconcentration on-line with the CE capillary. These devices have been used primarily for non-specific analyte preconcentration using packing material of the C18 type. Alternatively, the use of very specific antibody-containing cartridges and enzyme-immobilized microreactors have been demonstrated. In the current report, we review the likely impact of the technology of capillary electrophoresis and the role of the CE analyte concentrator-microreactor on the analysis of biomolecules, present on complex matrices, in a clinical laboratory. Specific examples of the direct analysis of physiologically-derived fluids and microdialysates are presented, and a personal view of the future of CE in the clinical environment is given.
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Affiliation(s)
- N A Guzman
- R. W. Johnson Pharmaceutical Research Institute, Raritan, NJ 08869, USA
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30
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Makino K, Goto Y, Sueyasu M, Futagami K, Kataoka Y, Oishi R. Micellar electrokinetic capillary chromatography for therapeutic drug monitoring of zonisamide. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 1997; 695:417-25. [PMID: 9300879 DOI: 10.1016/s0378-4347(97)00185-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The simultaneous determination of zonisamide, a new type of antiepileptic drug, and the typical antiepileptic drugs phenobarbital, phenytoin and carbamazepine in human serum was developed using micellar electrokinetic capillary chromatography (MECC) with a diode array detector. A high correlation was revealed between the zonisamide levels in human serum obtained by MECC and those obtained by high-performance liquid chromatography (r=0.981). The serum levels of phenobarbital, phenytoin and carbamazepine determined by MECC were almost equal to those obtained by fluorescence polarization immunoassay. The reproducibility of separation and quantification with MECC analysis was appropriate for the intra- and inter-day assay coefficients. Therefore, the MECC method established here could provide a simple and efficient therapeutic drug monitoring method for antiepileptic drugs in patients, especially those treated with a combination of zonisamide and other antiepileptic drugs.
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Affiliation(s)
- K Makino
- Department of Hospital Pharmacy, Faculty of Medicine, Kyushu University, Fukuoka, Japan
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31
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Vargas G, Havel J, Hadasová E. Direct determination of procainamide and N-acetylprocainamide by capillary zone electrophoresis in pharmaceutical formulations and urine. J Chromatogr A 1997; 772:271-6. [PMID: 9226929 DOI: 10.1016/s0021-9673(97)00106-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
In this work a new sensitive capillary zone electrophoresis method for the direct determination of procainamide (PA) and N-acetylprocainamide (NAPA) in pharmaceutical formulations and urine samples without any extraction and/or preconcentration steps has been developed. The determination was carried out in a fused-silica capillary of 43.5 cm (35.9 cm length to the detector) x 0.75 micron J.D. Phosphate 0.05 M buffer was used as the background electrolyte and 10 kV separation voltage was applied. The separation of PA and NAPA is possible in a wide range of pH from 1.7 to 9.7. However, in order to avoid the effect of the urine matrix, it is optimal to work at pH 7.7. The determination of PA and NAPA takes less than 5 min while high resolution is achieved. The detection limits obtained, 1.235 micrograms/ml and 0.359 microgram/ml for PA and NAPA respectively, are lower than those for GC method normally reported.
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Affiliation(s)
- G Vargas
- Department of Analytical Chemistry, Faculty of Science, Masaryk University, Brno, Czech Republic
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32
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Abstract
Micellar electrokinetic chromatography (MEKC) has become a popular mode among several capillary electromigration techniques. Most drug analyses can be performed by using MEKC because of its wide applicability. Enantiomer separation, separation of closely related peptides and isotopic compounds, separation of very complex mixtures, determination of drugs in the biological samples, etc., can be successfully achieved by MEKC. This review surveys typical applications of MEKC analysis. Recent advances in MEKC, especially with pseudo-stationary phases, are described. Modes of electrokinetic chromatography including MEKC, a separation theory of MEKC and selectivity manipulation in MEKC are also briefly mentioned.
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Affiliation(s)
- H Nishi
- Analytical Research Laboratory, Tanabe Seiyaku Co., Ltd., Osaka, Japan
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33
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Chapter 3 Electrokinetic chromatography. ACTA ACUST UNITED AC 1996. [DOI: 10.1016/s1464-3456(96)80020-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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34
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Taylor RB, Reid RG. Analysis of basic antimalarial drugs by CZE; Part 2. Validation and application to bioanalysis. J Pharm Biomed Anal 1995; 13:21-6. [PMID: 7718629 DOI: 10.1016/0731-7085(94)00127-n] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
This report describes some of the quantitative aspects of the CZE separation of proguanil, chloroquine and their respective metabolites, the separations of which, by CE and MEKC, were reported in Part 1. Results obtained on the precision of migration time and peak areas using the alternative injection methods of vacuum and electrokinetic are described and discussed. The increase in concentration sensitivity using electrokinetic injection with an organic injection solvent reported in Part 1 is confirmed and the resultant limits of detection in urine reported. An assay method for these compounds in urine is described which incorporates a pretreatment stage of solid phase extraction and the main analytical parameters used in the validation of such an assay are reported. The limitation of the sample pretreatment used when applied to matrices of plasma and saliva are reported and discussed in the context of the electrokinetic injection method used.
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Affiliation(s)
- R B Taylor
- School of Pharmacy, Robert Gordon University, Schoolhill, Aberdeen, UK
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35
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36
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Deyl Z, Tagliaro F, Miksík I. Biomedical applications of capillary electrophoresis. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL APPLICATIONS 1994; 656:3-27. [PMID: 7952043 DOI: 10.1016/0378-4347(94)00035-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
After having grown through the stages of technique development and instrumentation availability, capillary electrophoresis has reached the stage of applications. This review attempts to show the potential of this technique for biomedical analysis. Rather than going into a detailed description of the technical details of the separation conditions suitable for the separation of a particular category of compounds, the focus is on the general principles and areas in which this technique can be applied and the prospects for the future. Particular emphasis is placed on the separation of complex matrices and their simplification, a daily task in biomedical laboratories. In addition, methods for the optimization of separation conditions are considered. Considerable prospects for capillary electrophoresis lie in profiling. The applicability of the technique in peptide and protein mapping is discussed in some detail. Finally, three other topics are dealt with, namely enzymic activity microassays, drug-protein binding assays and monitoring of drugs in body fluids.
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Affiliation(s)
- Z Deyl
- Institute of Physiology, Academy of Sciences of the Czech Republic, Prague
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37
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Thormann W, Molteni S, Caslavska J, Schmutz A. Clinical and forensic applications of capillary electrophoresis. Electrophoresis 1994; 15:3-12. [PMID: 8143677 DOI: 10.1002/elps.1150150103] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
This survey is aimed at giving the readers a short overview of the present state of the art of clinical and forensic applications of capillary electrophoresis. First, the principles associated with electrokinetic capillary separations and instrumentation, sample preparation and solute quantitation are briefly discussed. This is followed by chapters describing the determination of endogenous and exogenous compounds in body fluids and tissue extracts. Finally, a survey of major achievements including reference to fully developed electrokinetic capillary assays is provided. The paper concludes with a brief outlook.
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Affiliation(s)
- W Thormann
- Department of Clinical Pharmacology, University of Bern, Switzerland
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38
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Tomlinson AJ, Benson LM, Johnson KL, Naylor S. Investigation of drug metabolism using capillary electrophoresis with photodiode array detection and online mass spectrometry equipped with an array detector. Electrophoresis 1994; 15:62-71. [PMID: 8143682 DOI: 10.1002/elps.1150150110] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The application of capillary electrophoresis (CE) with photodiode array detection (DAD) and on-line CE-mass spectrometry (CE-MS) equipped with a position and time resolved (PATRIC) focal plane detector for analysis of both in vitro and in vivo drug metabolism is demonstrated. Separation of metabolites derived from the neuroleptic drug haloperidol, by CE, using a simple, volatile run buffer containing 50 mM ammonium acetate with 10% methanol and 1% acetic acid is reported. The potential utility of CE-DAD for screening drug metabolite mixtures derived from hepatic microsomal incubations is demonstrated for haloperidol (HAL). Also the potential problems associated with using this technology to screen human urine samples for HAL metabolites is discussed. Furthermore, the usefulness of CE-MS and CE-electrospray ionization skimmer collision induced dissociation-MS (CE-ESI-CID-MS) in identification and structure elucidation of HAL metabolites derived from both a guinea pig hepatic microsomal incubation and urine from a patient treated with 0.5 mg/day of HAL is shown. The utility of such an approach in the general area of clinical pharmacology is also discussed.
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Affiliation(s)
- A J Tomlinson
- Biomedical Mass Spectrometry Facility, Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55905
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39
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Lee KJ, Lee JJ, Moon DC. Application of micellar electrokinetic capillary chromatography for monitoring of hippuric and methylhippuric acid in human urine. Electrophoresis 1994; 15:98-102. [PMID: 8143687 DOI: 10.1002/elps.1150150115] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The factors affecting micellar electrokinetic capillary chromatographic separation of hippuric and o-, m-, p-methylhippuric acid were investigated by changing the species of micelles, and adding urea to the micellar solution. The analysis of hippurates in human urine is demonstrated under optimum conditions using 20 mM phosphate buffer (pH 8.0) containing 100 mM dodecyltrimethylammonium bromide and 4 M urea at -22 kV applied voltage. This method proved suitable for the screening of hippurates in human urine following occupational exposure to toluene and xylene.
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Affiliation(s)
- K J Lee
- Chemical Analysis Laboratory, Korea Research Institute of Standards and Science, Taejonsi Taeduk Science Town
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40
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Tomita M, Okuyama T, Sato S, Ishizu H. Simultaneous determination of nitrazepam and its metabolites in urine by micellar electrokinetic capillary chromatography. JOURNAL OF CHROMATOGRAPHY 1993; 621:249-55. [PMID: 8294546 DOI: 10.1016/0378-4347(93)80102-a] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We applied micellar electrokinetic capillary chromatography to simultaneous separation and determination of nitrazepam and its major metabolites, 7-aminonitrazepam and 7-acetamidonitrazepam, in spiked urine. Prior to electrophoresis, the three compounds were successfully extracted from the spiked urine with commercial disposable solid-phase cartridges. The optimum running buffer for the separation was prepared by combining 85 parts of 60 mM sodium dodecyl sulphate-6 mM phosphate-borate, adjusted to pH 8.5, with 15 parts of methanol. The separation order, completed within 25 min, was 7-aminonitrazepam > 7-acetamidonitrazepam > nitrazepam, at an applied potential of 20 kV. We obtained reproducible electropherograms in successive repetitions, and few other peaks or interferences appeared in the electropherogram. The detection limits of the three compounds were 50-100 pg (0.1-0.2 microgram/ml of analyte in spiked urine), and the recoveries were 78.9-100.8% for 1 microgram/ml and 84.1-100.3% for 5 micrograms/ml. The application of this method to forensic or clinical samples is demonstrated.
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Affiliation(s)
- M Tomita
- Department of Legal Medicine, Kawasaki Medical School, Kurashiki, Japan
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41
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Lee KJ, Lee JJ, Moon DC. Determination of tricyclic antidepressants in human plasma by micellar electrokinetic capillary chromatography. JOURNAL OF CHROMATOGRAPHY 1993; 616:135-43. [PMID: 8376484 DOI: 10.1016/0378-4347(93)80480-r] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The factors affecting the micellar electrokinetic chromatographic separation of structurally similar tricyclic antidepressants (imipramine, amitriptyline, desipramine, nortriptyline, doxepin and trimipramine as an internal standard) were investigated by changing the species of micelles, and adding an organic modifier (urea or methanol) to the micellar solution. The determination of tricyclic antidepressants in human plasma is demonstrated under the optimum separation conditions using 37.5 mM phosphate buffer (pH 8.0) containing 25 mM dodecyltrimethylammonium bromide and 2 M urea at -25 kV applied voltage.
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Affiliation(s)
- K J Lee
- Organic Analytical Laboratory, Korea Research Institute of Standards and Science, Taejonsi Taeduk Science Town
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42
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Caslavska J, Lienhard S, Thormann W. Comparative use of three electrokinetic capillary methods for the determination of drugs in body fluids. Prospects for rapid determination of intoxications. J Chromatogr A 1993; 638:335-42. [PMID: 8331142 DOI: 10.1016/0021-9673(93)83446-y] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Three electrokinetic capillary methods, micellar electrokinetic capillary chromatography, capillary zone electrophoresis and capillary isotachophoresis, are shown to be well suited for the rapid screening and confirmation of drugs in serum and urine of patients with medical drug overdoses (intoxications), situations where rapid identification without precise quantification is needed. Patients' samples obtained from the emergency care unit were analysed in an instrument featuring on-column, fast forward-scanning multi-wavelength detection and the data were compared with those obtained by conventional methods. The drugs studied included salicylate, acetaminophen (paracetamol) and antiepileptics. In cases with high drug concentrations, body fluids can be injected directly or may have only to be diluted (urine) or ultrafiltered (serum) prior to analysis, providing results within about 30 min. Thus, electrokinetic capillary methods can be employed for rapid drug screening, provided that instrumentation with a database for peak identification is available.
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Affiliation(s)
- J Caslavska
- Department of Clinical Pharmacology, University of Berne, Switzerland
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43
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Thormann W, Lienhard S, Wernly P. Strategies for the monitoring of drugs in body fluids by micellar electrokinetic capillary chromatography. J Chromatogr A 1993; 636:137-48. [PMID: 8491833 DOI: 10.1016/0021-9673(93)80066-h] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Electrokinetic capillary techniques can exploit numerous separation principles, making them flexible and easily applicable to a variety of separation problems. In recent publications, this emerging technology has been shown to be well suited for monitoring drugs and metabolites in body fluids, including serum, saliva and urine. Most attention has been focused on micellar electrokinetic capillary chromatography (MECC) because it permits the separation and determination of drugs with discrimination being largely based on differences in hydrophobicity. An overview of literature data on the MECC of drugs in body fluids and recent data obtained with antiepileptics in serum and saliva, with model mixtures of illicit drugs, and with extracts from urine specimens that tested positively for opiates and cocaine metabolites are presented. Emphasis is focused on buffer selection and simple sample preparation procedures, including direct injection of body fluids, ultrafiltration and solid-phase extraction.
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Affiliation(s)
- W Thormann
- Department of Clinical Pharmacology, University of Berne, Switzerland
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