Simultaneous analysis of theophylline, caffeine and eight of their metabolic products in human plasma by gradient high-performance liquid chromatography

Leakey, T E

doi:10.1016/s0021-9673(01)84196-0

Cited by 44 publications

(11 citation statements)

References 28 publications

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“…Caffeine, theobromine and theophylline were analysed by a Kjeldahl method [3], UV-spectrometry [4], thin-layer chromatography [5,6], gas chromatography [7], potentiometric titrations [8] and HPLC [9][10][11]. Adenine was determined by adsorptive stripping voltammetry [12], gas chromatography [13], capillary zone electrophoresis [14] and HPLC [15,16].…”

Section: Introductionmentioning

confidence: 99%

“…Reversedphase HPLC with UV-detection has been successfully applied for the separation and determination of these compounds in a range of foods, beverages and biological fluids [9][10][11][17][18][19]. In some cases amperometric detection [20][21][22] or cathodic stripping voltammetry [16] was preferred, because of the higher sensitivity and selectivity of these detection techniques.…”

Section: Introductionmentioning

confidence: 99%

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Determination of adenine, caffeine, theophylline and theobromine by HPLC with amperometric detection

Meyer

Ngiruwonsanga

Henze

1996

Analytical and Bioanalytical Chemistry

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A relatively simple method for quantifying caffeine, theobromine, theophylline and adenine by HPLC with amperometric detection was developed. A C(18)-column and an isocratic elution with phosphate buffer pH 3.5/methanol (90 : 10) were employed for the chromatographic separation of the investigated compounds. The optimal detection potential was +1.4 V. The limits of detection were 0.4 ng for adenine, 1 ng for theophylline and 2.5 ng for caffeine and theobromine. The method was applied to the determination of these purine alkaloids in beverages, tea, coffee and cacao. The determination was carried out directly or after solid-phase extraction.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Determination of adenine, caffeine, theophylline and theobromine by HPLC with amperometric detection

Meyer

Ngiruwonsanga

Henze

1996

Analytical and Bioanalytical Chemistry

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“…distribution (Yd) (7). It is mainly metabolized by the liver (with a half-life averaging about 3.5 h in children and 8 h in adults) and its major metabolites are 3-methylxanthine, I-methyluric acid and 1,3-dimethyluric acid (7,(18)(19)(20). Although theophylline's metabolism could be represented by linear kinetics (21), there is evidence that at least one metabolic pathway exhibits saturation kinetics that follows the general form of the Michaelis-Menten equation (18,22).…”

Section: Theophylline Eliminationmentioning

confidence: 99%

“…Since theophylline is structurally related to its metabolites and caffeine, which is present from various dietary sources in many samples, it is important that any assay employed is free from interference from such compounds (19). High-performance liquid chromatography based techniques not only meet these requirements, but also can be used in emergency clinical situations and a number of such assays have been recently developed (20,26). The pharmacokinetic data thus obtained can be used to estimate the values of the system parameters through fitting to Equation I a-d.…”

Section: Analytical Solutionmentioning

confidence: 99%

Individualization of theophylline infusion rate on the basis of a nonlinear compartmental pharmacokinetic model

Nikiforidis

Argyropoulos

Kassimatis

et al. 1997

European Journal of Drug Metabolism and Pharmacokinetics

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In the present paper, a nonlinear compartmental model for theophylline pharmacokinetics is developed. The analytical solution of the model, in parametric form, is derived under plateau conditions for plasma metabolite concentration. The parameters are obtained from plasma and urine data using best fitting techniques and their values are used in order to calculate maintenance intravenous infusion. Numerical simulation is then performed in order to compare the drug concentration obtained by our approach with that of alternative intravenous regimens. The differences argue for individualized dosage regimens, since theophylline is a drug with a narrow therapeutic window and its concentration at the active sites strongly depends on characteristic parameters of the patient's response. Our results show that it is possible to estimate the patients' parameters during the first 8 h after intravenous administration of the drug and these parameters can be used to design an individualized dosage regimen in patients receiving theophylline intravenously.

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“…A number of studies have been published during the past 15 years, which have been directed toward the characterization of the cytochrome p 450 (cyp) isoforms involved in the different pathways. Reported analytical procedures for theophylline metabolites in body fluids have been based on the methods of liquid chromatography with ultraviolet, [1][2][3][4][5][6][7][8][9] electrochemical, [10][11][12] immunoassay [13][14] and capillary electrophoresis detection. [15][16] In a previous investigation the advantage of using a solvent program 1,2,6,8 and ternary solvent 4,5,7,9 for LC-UV determination of theophylline and its metabolites in serum and urine samples was established.…”

Section: Introductionmentioning

confidence: 99%

Use of a Disposable Modified Carbon Paste Electrode for Liquid Chromatography‐amperometric Detection of Theophylline and Three Metabolites in Human Serum

Wang¹,

Tien²,

Tai³

2006

J Chinese Chemical Soc

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Chemically modified electrodes, constructed by incorporating potassium hexachloroplatinate K 2 PtCl 6 into the graphite power/paraffin oil matrix used to fabricate conventional carbon paste electrodes, were shown to catalyze the electrooxidation of purine compounds including theophylline, 3-methylxanthine, 1,3-dimethyluric acid and 1-methyluric acid; the modifier electrodes display electrocatalytic activity for the oxidation of purines at 170 mV (vs Ag/AgCl) when used as sensing electrodes in amperometric detection following liquid chromatography. The K 2 PtCl 6 electrodes permitted detection of the purines at similar values of applied potential. The limit of detection (LOD) of theophylline, 1-MUA, 3-MXT and 1,3-DMUA were 1.1 ng mL -1 , 3.2 ng mL -1 , 1.0 ng mL -1 and 11 ng mL -1 , respectively. The calibration graphs were linear for theophylline and metabolites over the range of concentration used (50-3200 ng mL -1 ). Theophylline and its metabolites can easily be separated and analyzed in one run using electrochemical sensor chromatography with a methanol -phosphate buffer containing 20 mM di-potassium hydrogen phosphate (pH 5.50). Serum samples were collected after the oral administration of black tea from human volunteers. Quantitative data for the determination of a micromolar amount of theophylline and its metabolites in serum samples are in agreement with data obtained by HPLC-UV.

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Simultaneous analysis of theophylline, caffeine and eight of their metabolic products in human plasma by gradient high-performance liquid chromatography

Cited by 44 publications

References 28 publications

Determination of adenine, caffeine, theophylline and theobromine by HPLC with amperometric detection

Determination of adenine, caffeine, theophylline and theobromine by HPLC with amperometric detection

Individualization of theophylline infusion rate on the basis of a nonlinear compartmental pharmacokinetic model

Use of a Disposable Modified Carbon Paste Electrode for Liquid Chromatography‐amperometric Detection of Theophylline and Three Metabolites in Human Serum

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