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Mohammed G, Khraibah N, Bashammakh A, El-Shahawi M. Electrochemical sensor for trace determination of timolol maleate drug in real samples and drug residues using Nafion/carboxylated-MWCNTs nanocomposite modified glassy carbon electrode. Microchem J 2018. [DOI: 10.1016/j.microc.2018.08.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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2
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Development of a novel ion-pairing UPLC method with cation-exchange solid-phase extraction for determination of free timolol in human plasma. J Chromatogr B Analyt Technol Biomed Life Sci 2018; 1096:228-235. [DOI: 10.1016/j.jchromb.2018.08.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 07/16/2018] [Accepted: 08/19/2018] [Indexed: 01/08/2023]
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3
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Alizadeh T, Ganjali MR, Rafiei F, Akhoundian M. Synthesis of nano-sized timolol-imprinted polymer via ultrasonication assisted suspension polymerization in silicon oil and its use for the fabrication of timolol voltammetric sensor. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2017; 77:300-307. [DOI: 10.1016/j.msec.2017.03.168] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 11/14/2016] [Accepted: 03/20/2017] [Indexed: 11/29/2022]
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4
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Simultaneous determination of timolol maleate in combination with some other anti-glaucoma drugs in rabbit aqueous humor by high performance liquid chromatography–tandem mass spectroscopy. J Chromatogr B Analyt Technol Biomed Life Sci 2016; 1022:109-117. [DOI: 10.1016/j.jchromb.2016.04.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 04/04/2016] [Accepted: 04/05/2016] [Indexed: 11/22/2022]
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5
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Itxaso Maguregui M, Alonso RM, Jiménez RM. A Rapid Quantitative Analysis of the β-Blocker Timolol in Human Urine by HPLC-Electrochemical Detection. J LIQ CHROMATOGR R T 2006. [DOI: 10.1080/10826079608005498] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- M. Itxaso Maguregui
- a Departamento de Química Analítica Facultad de Ciencias , Universidad del País Vasco/EHU , Apdo. 644, 48080, Bilbao, Spain
| | - Rosa M. Alonso
- a Departamento de Química Analítica Facultad de Ciencias , Universidad del País Vasco/EHU , Apdo. 644, 48080, Bilbao, Spain
| | - Rosa M. Jiménez
- a Departamento de Química Analítica Facultad de Ciencias , Universidad del País Vasco/EHU , Apdo. 644, 48080, Bilbao, Spain
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6
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Arranz A, Dolara I, Fernández de Betoño S, Marı́a Moreda J, Cid A, Francisco Arranz J. Electroanalytical study and square wave voltammetric techniques for the determination of β-blocker timolol at the mercury electrode. Anal Chim Acta 1999. [DOI: 10.1016/s0003-2670(99)00214-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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7
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Ohtori R, Sato H, Fukuda S, Ueda T, Koide R, Kanda Y, Kiuchi Y, Oguchi K. Pharmacokinetics of topical beta-adrenergic antagonists in rabbit aqueous humor evaluated with the microdialysis method. Exp Eye Res 1998; 66:487-94. [PMID: 9593641 DOI: 10.1006/exer.1997.0448] [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: 11/22/2022]
Abstract
The microdialysis method was used to evaluate the pharmacokinetics of the beta-adrenergic antagonists carteolol and timolol and the new ophthalmic solution WP-934 in rabbit aqueous humor, following instillation. A probe with a microdialysis membrane (length, 5 mm; diameter, 0.2 mm) was implanted in the anterior chamber of the pigmented rabbit and perfused with Ringer's solution. Twenty microliters of 0.5% timolol maleate (0.5% Timoptol(R)), 2% carteolol hydrochloride (2% Mikelan(R)), or a novel preparation of 0.5% timolol maleate (WP-934) that gels after instillation were then instilled. The concentrations of these drugs in dialysates were measured using high-performance liquid chromatography and an electrochemical detection system. In vitro relative recovery of the membrane with timolol and carteolol was approximately 17.5% and 21. 6%, respectively. Timolol and carteolol levels in aqueous humor increased rapidly after instillation of Timoptol and Mikelan and reached maximal levels (Cmax) within 60 minutes. The Cmax of carteolol (4.25 microg ml-1) was lower than that of timolol (5.52 microg ml-1), suggesting that the corneal permeability of timolol is higher than that of carteolol. After instillation of WP-934, the Cmax of timolol (12.32 microg ml-1) was 2.2-fold higher than that after instillation of Timoptol. However, t1/2 values of beta-adrenergic antagonists after instillation of the three preparations were not significantly different. These data suggest that the microdialysis technique is useful for continuous monitoring of aqueous levels of beta-blockers and for analysis of their pharmacokinetic parameters while requiring much fewer animals than conventional sampling with paracentesis.
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Affiliation(s)
- R Ohtori
- Department of Ophthalmology, Showa University School of Medicine, 1-5-8 Hatanodai, Tokyo, Shinagawa-ku, 142-0064, Japan
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8
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Rossi DT, Wright DS. Analytical considerations for trace determinations of drugs in breast milk. J Pharm Biomed Anal 1997; 15:495-504. [PMID: 8953493 DOI: 10.1016/s0731-7085(96)01880-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Recent scientific and regulatory interest in lacteal excretion of drugs has prompted this review of bioanalytical sample preparation techniques for milk. The composition and properties of milk are reviewed, with emphasis on how the sample preparation is affected. The most important principals of mammary gland pharmacology, including protein binding, ion trapping and liquid solubility, are described. Because adequate milk volume is difficult to obtain from some smaller rodent species, special arrangements for sample collection, control preparation and assay standardization often need to be made. Several commonly-used sample preparation approaches for drugs in milk, including direct injection, dialysis and ultrafiltration, protein precipitation, liquid-liquid extraction, solid-phase extraction and immunoaffinity extraction. Have been reported with varying degrees of success. The advantages and disadvantages of each of these approaches is discussed.
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Affiliation(s)
- D T Rossi
- Department of Pharmacokinetics and Drug Metabolism, Parke-Davis Pharmaceutical Research, Division of Warner-Lambert Company, Ann Arbor, MI, USA. Rossi01/aa.wl.corr
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9
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Maguregui MI, Alonso RM, Jiménez RM. High-performance liquid chromatography with amperometric detection applied to the screening of beta-blockers in human urine. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL APPLICATIONS 1995; 674:85-91. [PMID: 8749255 DOI: 10.1016/0378-4347(95)00303-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A high-performance liquid chromatographic method with electrochemical detection has been developed for the determination of six beta-blockers: atenolol, nadolol, timolol, metoprolol, oxprenolol, and alprenolol. The chromatographic separation was performed using a mu Bondapack C18 column, a mobile phase of acetonitrile-water (40:60), containing 5 mM KH2PO4/K2HPO4 proved to be optimal at a 1.3 ml/min flow-rate, and a pH of 6.5. The temperature was optimized at 30 +/- 0.2 degrees C. The amperometric detector, equipped with a glassy carbon electrode, was operated at 1300 mV versus Ag/AgCl in the direct current mode. The method was applied to the determination of these compounds at two concentration levels: ppm and ppb (ng/ml), obtaining relative standard deviations lower than 5% at ppm levels and lower than 10% at ppb levels, and quantitation limits ranging from 15 ppb to 500 ppb. The method was applied to the screening of beta-blockers in spiked urine samples, with a total elution time lower than 12 min, obtaining the best recoveries for timolol and metoprolol (never greater than 93%). These recoveries together with the low limits of quantitation achieved, allows its application to doping analysis in human urine.
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Affiliation(s)
- M I Maguregui
- Departamento de Química Analítica, Facultad de Ciencias, Universidad del País Vasco, Bilbao, Spain
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10
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He H, Edeki TI, Wood AJ. Determination of low plasma timolol concentrations following topical application of timolol eye drops in humans by high-performance liquid chromatography with electrochemical detection. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL APPLICATIONS 1994; 661:351-6. [PMID: 7894678 DOI: 10.1016/0378-4347(94)00357-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A simple and sensitive high-performance liquid chromatographic assay was developed for determination of timolol in human plasma following administration of two drops of a 5% timolol ophthalmic solution. A 4% butyl alcohol-hexane extract of an alkalized sample of plasma was chromatographed on a reversed-phase column and the components in the column effluent were monitored by coulometric detection. The extraction efficiency of timolol was 69.02 +/- 4.16% (mean +/- S.D.) and its detection limit was 107.2 pg/ml. The effect of mobile phase pH, buffer concentration and the working potential of the detector on column performance and the electrochemical response are described.
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Affiliation(s)
- H He
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232-6620
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11
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Olah TV, Gilbert JD, Barrish A. Determination of the beta-adrenergic blocker timolol in plasma by liquid chromatography-atmospheric pressure chemical ionization mass spectrometry. J Pharm Biomed Anal 1993; 11:157-63. [PMID: 8504187 DOI: 10.1016/0731-7085(93)80136-o] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
A method based on LC-MS-MS has been developed for the determination of timolol in plasma using the (CD3)3-labelled species as the internal standard. Timolol is isolated from plasma by a simple solid-phase extraction and converted to its oxazolidin-2-one prior to analysis on a 50 x 4.6 mm reversed-phase high-performance liquid chromatography column packed with SynChropak, C18, 5 microns. The column eluate is passed by means of a heated nebulizer interface into a corona discharge atmospheric pressure chemical ionization source where the analyte and its internal standard are detected using multiple reaction monitoring (MRM). The very high specificity of this technique permits chromatographic run times of less than 2 min. The method has a lower quantifiable limit of 0.5 ng ml-1, with intra- and inter-day relative standard deviations less than 10%, and enables the determination of timolol in plasma after ocular administration to volunteers.
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Affiliation(s)
- T V Olah
- Merck Research Laboratories, West Point, PA 19486
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12
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Abstract
A sensitive and reproducible radioreceptor assay (RRA) is described for the determination of low picogram levels of timolol in plasma. The plasma or serum samples (1 mL) are prepared by selectively extracting timolol with lipophilic solvents or, alternatively, only plasma (serum) proteins are precipitated prior to binding assay. The recovery of timolol is at least 90% during the sample preparation. In the radioligand binding assay, timolol and the nonselective beta-antagonist [3H](-)-CGP-12177 compete for the binding sites present in the rat reticulocyte membranes. The detection limit for timolol (30 pg/mL) exceeds 50 times the sensitivity of the GC-MS techniques for timolol. The RRA results and GC results obtained from the same clinical samples correlate excellently (r = 0.99). There was no evidence for interference caused by timolol metabolites in the RRA. Timolol concentrations in plasma following its oral and even ocular administration were possible to monitor using the RRA. The method can be modified to also measure several other beta-antagonist drugs in picogram per milliliter quantities.
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Affiliation(s)
- T Kaila
- Department of Clinical Pharmacology, University of Turku, Finland
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13
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Kubota K, Nakamura H, Koyama E, Yamada T, Kikuchi K, Ishizaki T. Simple and sensitive determination of timolol in human plasma and urine by high-performance liquid chromatography with ultraviolet detection. JOURNAL OF CHROMATOGRAPHY 1990; 533:255-63. [PMID: 2081773 DOI: 10.1016/s0378-4347(00)82211-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- K Kubota
- Division of Clinical Pharmacology, National Medical Center, Tokyo, Japan
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14
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Wu PY, Riegel M, Ellis PP. High-performance liquid chromatographic assay for timolol in the aqueous humor of the eye. JOURNAL OF CHROMATOGRAPHY 1989; 494:368-75. [PMID: 2584335 DOI: 10.1016/s0378-4347(00)82690-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- P Y Wu
- Department of Ophthalmology, University of Colorado School of Medicine, Denver 80262
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Soltés L. High-performance liquid chromatographic determination of beta-adrenoceptor blocking agents in body fluids. Biomed Chromatogr 1989; 3:139-52. [PMID: 2574057 DOI: 10.1002/bmc.1130030402] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Several reports have been published reviewing high-performance liquid chromatographic (HPLC) methods for the determination of beta-adrenoceptor blocking agents (beta-blockers) in biological materials (Flouvat et al., 1981; Mehta, 1983; Marko and Soltés, 1984; Ahnoff et al., 1985; Tkaczyková and Safarík, 1987). Of these, the paper by Mehta (1983) briefly summarizes the interrelationship between physiocochemical properties of beta-blockers with prechromatographic treatment of biological samples, as well as with the HPLC methods used for the determination of 12 beta-adrenoceptor blocking drugs. The work by Ahnoff et al. (1985) concerning the monitoring of cardiovascular drugs also deals with HPLC assays of 18 beta-blockers in plasma. The Appendix to this report presents the great majority of HPLC methods for determining 30 beta-blockers in various body fluids. HPLC methods providing resolution and determination of individual beta-blocker enantiomers have not been included since this topic is being covered by Walle and Walle (1989). The Appendix is just a guide to the methods reviewed for the HPLC determination of parent beta-blockers as well as some of their metabolites co-assayed in various body fluids. It does not include details such as the internal standard, recovery, setting of the detector, limit of determination, etc., given in the individual methods listed. The isolation technique of the drug(s) from the given body fluid represents the main step in the sample work-up procedure. Along with this information, only the type of the HPLC column packing and the detection principle used by each method's developers are given.
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Affiliation(s)
- L Soltés
- Institute of Experimental Pharmacology, Slovak Academy of Sciences, Bratislava, Czechoslovakia
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Mazzo DJ, Synder PA. High-performance liquid chromatography of timolol and potential degradates on dynamically modified silica. J Chromatogr A 1988; 438:85-92. [PMID: 2837497 DOI: 10.1016/s0021-9673(00)90235-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
A novel method for the determination of timolol in pharmaceutical products has been developed and is described. The method employs high-performance liquid chromatography (HPLC) on silica dynamically modified with the cetyltrimethylamomonium cation to quantitate the analyte. The use of this type of reversed-phase HPLC system for timolol determinations results in improved quality of chromatography, especially in terms of peak tailing and peak efficiency, in comparison to chromatography on bonded-phase silica. Column-to-column as well as manufacturer-to-manufacturer reproducibility for this separation on silica columns has been obtained and is better in our hands than that encountered with bonded-phase column packings. The method has been shown to be linear for the compounds studied, comparably accurate and precise to bonded-phase methods and specific for timolol in a variety of pharmaceutical formulations. Under the conditions specified, timolol can be successfully separated from its three potential degradates. Possible explanations of the primary retention mechanisms for the analytes are offered.
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Affiliation(s)
- D J Mazzo
- Department of Pharmaceutical Research and Development, Merck Sharp & Dohme Research Laboratories, West Point, PA 19486
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Mok V, Bui LV, Chan LT. Capillary gas chromatographic-mass spectrometric study of the effect of solvents on metoprolol and other aryloxypropanolamines. J Chromatogr A 1987; 393:335-42. [PMID: 2885334 DOI: 10.1016/s0021-9673(01)94232-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
When metoprolol in methanol was analysed by capillary gas chromatography (GC), an additional peak was observed; mass spectrometry (MS) showed this additional peak to have a molecular weight 12 dalton higher than that of the parent compound. A similar phenomenon was observed with other beta-adrenergic blocking aryloxypropanolamines in methanol or dichloromethane. Capillary GC-MS using deuterated solvents as isotopic markers showed that a methylene group from the solvents was incorporated into the parent molecule. The structure of the observed products and the mechanism of their formation are proposed.
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18
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Timolol Maleate. ACTA ACUST UNITED AC 1987. [DOI: 10.1016/s0099-5428(08)60566-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
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Maurer H, Pfleger K. Identification and differentiation of beta-blockers and their metabolites in urine by computerized gas chromatography-mass spectrometry. JOURNAL OF CHROMATOGRAPHY 1986; 382:147-65. [PMID: 2878002 DOI: 10.1016/s0378-4347(00)83513-6] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A method for the identification and differentiation of beta-blockers and their metabolites in urine after acid hydrolysis is described. The acetylated extract is analysed by computerized gas chromatography-mass spectrometry. An on-line computer allows rapid detection using ion chromatography with the ions of m/z 72, 86, 98, 140, 151, 159, 200 and 335. The identity of positive signals in the reconstructed ion chromatogram is confirmed by a comparison of the stored entire mass spectra with the reference spectra. The ion chromatogram, the reference mass spectra and the gas chromatographic retention indices (OV-101) are documented. References for the quantitation of the single beta-blockers are cited.
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Musch G, De Smet M, Massart DL. Expert system for pharmaceutical analysis. I. Selection of the detection system in high-performance liquid chromatographic analysis: UV versus amperometric detection. J Chromatogr A 1985; 348:97-110. [PMID: 2868023 DOI: 10.1016/s0021-9673(01)92443-4] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The usefulness of amperometric detection in pharmaceutical analyses was investigated for different groups of drugs. The UV response at 254 nm and that at the absorption maximum of the solute were compared with the electrochemical signal obtained. The minimum detectable concentration (nanograms on-column) of each substance is reported for the three different detection systems. This comparison was performed for 72 drugs (local anaesthetics, antipyretics, tricyclic antidepressants, sulphonamides, sex hormones, beta-adrenoceptor blocking agents, phenothiazines, alkaloids, diuretics and penicillins). The median limit of detection of the amperometric detector (see definition in the text) is 1.0 ng on-column and the median gain in sensitivity, compared with UV detection is 22.5.
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Ahnoff M, Ervik M, Lagerström PO, Persson BA, Vessman J. Drug level monitoring: cardiovascular drugs. JOURNAL OF CHROMATOGRAPHY 1985; 340:73-138. [PMID: 2862159 DOI: 10.1016/0378-4347(85)80195-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Methods for the determination of cardiovascular drugs in blood and plasma are critically reviewed with emphasis on gas and liquid chromatographic techniques. The importance of the various procedures is discussed, in particular sample work-up where the conditions for isolation and derivatization of the compounds are decisive for the accuracy and precision of the methods. Compared with other assay techniques chromatographic methods are generally to be preferred owing to their better selectivity. In the review the following groups are discussed: digitalis glycosides, antiarrhythmic agents, beta-adrenoceptor antagonists, vasodilating agents, antihypertensive compounds, and diuretics.
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Lennard MS, Parkin S. Timolol determination in plasma and urine by high-performance liquid chromatography with ultraviolet detection. JOURNAL OF CHROMATOGRAPHY 1985; 338:249-52. [PMID: 4019651 DOI: 10.1016/0378-4347(85)80094-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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23
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Gregg MR. Increased electrochemical detector sensitivity by electrode surface modification. Chromatographia 1985. [DOI: 10.1007/bf02280612] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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