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Analysis of free concentrations of lamotrigine and active oxcarbazepine metabolite in clinical patients by hollow-fiber centrifugal ultrafiltration. Bioanalysis 2022; 14:795-806. [PMID: 35848797 DOI: 10.4155/bio-2022-0048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Aim: To establish a simple and accurate method to explore the correlation between free and total concentrations of lamotrigine (LTG) and the active oxcarbazepine metabolite monohydroxy derivative (MHD) (10,11-dihydro-10-hydroxycarbamazepine) in clinical patients. Materials & methods: Serum samples were prepared by hollow-fiber centrifugal ultrafiltration and then injected into UPLC for analysis. Results: Absolute recovery was as high as approximately 90.1-98.6% with excellent precision (relative standard deviation <6.7%). Analysis time was reduced to 5 min. There were significant individual differences in the protein binding rates of both LTG and MHD that were probably due to the use of different clinical patients. Conclusion: Free concentrations of LTG and MHD cannot be estimated by total concentration in specific clinical patients. Free drug monitoring of LTG and MHD in clinical therapeutic drug monitoring is important and essential.
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Begas E, Tsakalof A, Dardiotis E, Vatidis GE, Kouvaras E, Asprodini EK. Development and validation of a reversed-phase HPLC method for licarbazepine monitoring in serum of patients under oxcarbazepine treatment. Biomed Chromatogr 2017; 31. [PMID: 28182284 DOI: 10.1002/bmc.3950] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 02/01/2017] [Accepted: 02/07/2017] [Indexed: 11/06/2022]
Abstract
Licarbazepine is the pharmacologically active metabolite of oxcarbazepine, a drug indicated for the treatment of partial seizures and bipolar disorders. Several HPLC methods have been developed thus far but there is lack of control for interferences from antipsychotic drugs. The aim of the present study was to develop a simple, low-cost and reliable HPLC-UV method for the determination of licarbazepine in human serum in the presence of co-administered antiepileptic, antipsychotic and commonly prescribed drugs. Sample preparation consisted of a single protein precipitation step with methanol. Separation lasted ~9 min on a reversed-phase C18 column using a mobile phase composed of 50 mm sodium-dihydrogen-phosphate-monohydrate/acetonitrile (70:30, v/v) delivered isocratically at 0.9 mL/min and 30°C. Wavelength was 210 nm and calibration curve was linear with r2 0.998 over the range 0.2-50.0 μg/mL. Coefficient of variation was <5.03% and bias <-4.92%. Recovery ranged from 99.49 to 104.52% and the limit of detection was 0.0182 μg/mL. No interferences from the matrix or from antiepileptic, antipsychotic and commonly prescribed drugs were observed. The method was applied to serum samples of patients under oxcarbazepine treatment and proved to be a useful tool for the therapeutic drug monitoring of licarbazepine during monotherapy or adjunctive treatment of seizures or affective disorders.
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Affiliation(s)
- Elias Begas
- Laboratory of Pharmacology, School of Medicine, University of Thessaly, Larissa, Greece
| | - Andreas Tsakalof
- Laboratory of Chemistry, School of Medicine, University of Thessaly, Larissa, Greece
| | - Efthimios Dardiotis
- Department of Neurology, University Hospital of Larissa, School of Medicine, University of Thessaly, Larissa, Greece
| | | | - Evangelos Kouvaras
- Laboratory of Pharmacology, School of Medicine, University of Thessaly, Larissa, Greece
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3
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Development and validation of an enantioselective SFC-MS/MS method for simultaneous separation and quantification of oxcarbazepine and its chiral metabolites in beagle dog plasma. J Chromatogr B Analyt Technol Biomed Life Sci 2016; 1020:36-42. [DOI: 10.1016/j.jchromb.2016.03.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 03/12/2016] [Accepted: 03/14/2016] [Indexed: 11/22/2022]
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4
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Lewis RJ, Angier MK, Johnson RD. False Carbamazepine Positives Due to 10,11-Dihydro-10-Hydroxycarbamazepine Breakdown in the GC–MS Injector Port†. J Anal Toxicol 2014; 38:519-23. [DOI: 10.1093/jat/bku064] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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5
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Reddy PS, Babu KS, Kumar N. Development and validation of a stability-indicating RP-LC method for the estimation of process-related impurities and degradation products of oxcarbazepine in pharmaceutical formulation. ACTA CHROMATOGR 2014. [DOI: 10.1556/achrom.26.2014.2.6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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6
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Serralheiro A, Alves G, Fortuna A, Rocha M, Falcão A. First HPLC–UV method for rapid and simultaneous quantification of phenobarbital, primidone, phenytoin, carbamazepine, carbamazepine-10,11-epoxide, 10,11-trans-dihydroxy-10,11-dihydrocarbamazepine, lamotrigine, oxcarbazepine and licarbazepine in human plasma. J Chromatogr B Analyt Technol Biomed Life Sci 2013; 925:1-9. [DOI: 10.1016/j.jchromb.2013.02.026] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Revised: 02/21/2013] [Accepted: 02/22/2013] [Indexed: 01/19/2023]
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7
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Therapeutic drug monitoring and LC–MS/MS. J Chromatogr B Analyt Technol Biomed Life Sci 2012; 883-884:33-49. [DOI: 10.1016/j.jchromb.2011.09.041] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Revised: 09/14/2011] [Accepted: 09/22/2011] [Indexed: 11/24/2022]
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8
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Fortuna A, Sousa J, Alves G, Falcão A, Soares-da-Silva P. Development and validation of an HPLC-UV method for the simultaneous quantification of carbamazepine, oxcarbazepine, eslicarbazepine acetate and their main metabolites in human plasma. Anal Bioanal Chem 2010; 397:1605-15. [DOI: 10.1007/s00216-010-3673-0] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2010] [Revised: 03/20/2010] [Accepted: 03/21/2010] [Indexed: 11/28/2022]
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9
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Saracino MA, Tallarico K, Raggi MA. Liquid chromatographic analysis of oxcarbazepine and its metabolites in plasma and saliva after a novel microextraction by packed sorbent procedure. Anal Chim Acta 2010; 661:222-8. [DOI: 10.1016/j.aca.2009.12.030] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2009] [Revised: 12/18/2009] [Accepted: 12/21/2009] [Indexed: 11/28/2022]
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10
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Sauer C, Peters FT, Haas C, Meyer MR, Fritschi G, Maurer HH. New designer drug alpha-pyrrolidinovalerophenone (PVP): studies on its metabolism and toxicological detection in rat urine using gas chromatographic/mass spectrometric techniques. JOURNAL OF MASS SPECTROMETRY : JMS 2009; 44:952-964. [PMID: 19241365 DOI: 10.1002/jms.1571] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The aim of the present study was to identify the metabolites of the new designer drug alpha-pyrrolidinovalerophenone (PVP) in rat urine using GC/MS techniques. Eleven metabolites of PVP could be identified suggesting the following metabolic steps: hydroxylation of the side chain followed by dehydrogenation to the corresponding ketone; hydroxylation of the 2''-position of the pyrrolidine ring followed by dehydrogenation to the corresponding lactam or followed by ring opening to the respective aliphatic aldehyde and further oxidation to the respective carboxylic acid; degradation of the pyrrolidine ring to the corresponding primary amine; and hydroxylation of the phenyl ring, most probably in the 4'-position. The authors' screening procedure for pyrrolidinophenones allowed the detection of PVP metabolites after application of a dose corresponding to a presumed user's dose. In addition, the involvement of nine different human cytochrome P450 (CYP) isoenzymes in the side chain hydroxylation of PVP was investigated and CYP 2B6, 2C19, 2D6, and 3A4 were found to catalyze this reaction.
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Affiliation(s)
- Christoph Sauer
- Department of Experimental and Clinical Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, Saarland University, D-66421 Homburg (Saar), Germany
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11
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Staack RF, Theobald DS, Paul LD, Springer D, Kraemer T, Maurer HH. In vivometabolism of the new designer drug 1-(4-methoxyphenyl)piperazine (MeOPP) in rat and identification of the human cytochrome P450 enzymes responsible for the major metabolic step. Xenobiotica 2008; 34:179-92. [PMID: 14985146 DOI: 10.1080/00498250310001644544] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
1. The in vivo metabolism of 1-(4-methoxyphenyl)piperazine (MeOPP), a novel designer drug, was studied in male Wistar rats. 2. MeOPP was mainly O-demethylated to 1-(4-hydroxyphenyl)piperazine (4-HO-PP) in addition to degradation of the piperazine moiety. 3. O-demethylation, the major metabolic step, was studied with cDNA-expressed human hepatic cytochrome P450 (CYP) enzymes in pooled human liver microsomes (pHLM) and in single donor human liver microsomes with CYP2D6 poor metabolizer genotype (PM HLM). 4. CYP2D6 catalysed O-demethylation with apparent Km and Vmax values of 48.34 +/- 14.48 microM and 5.44 +/- 0.47 pmol min(-1) pmol(-1) CYP, respectively. pHLM catalysed the monitored reaction with an apparent Km = 204.80 +/- 51.81 microM and Vmax = 127.50 +/- 13.25 pmol min(-1) mg(-1) protein. 5. The CYP2D6-specific chemical inhibitor quinidine (1 and 3 microM) significantly inhibited 4-HO-PP formation by 71.9 +/- 4.8% and by 98.5% +/- 0.5%, respectively, in incubation mixtures with pHLM and 200 microM MeOPP. 6. O-demethylation was significantly lower in PM HLM compared with pHLM (70.6% +/- 7.2%). 7. These data suggest that polymorphically expressed CYP2D6 is the enzyme mainly responsible for MeOPP O-demethylation.
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Affiliation(s)
- R F Staack
- Department of Experimental and Clinical Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, University of Saarland, D-66421 Homberg (Saar), Germany
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12
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Springer D, Staack RF, Paul LD, Kraemer T, Maurer HH. Identification of cytochrome P450 enzymes involved in the metabolism of 3′,4′-methylenedioxy-α-pyrrolidinopropiophenone (MDPPP), a designer drug, in human liver microsomes. Xenobiotica 2008; 35:227-37. [PMID: 16019948 DOI: 10.1080/00498250400028239] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The metabolism of 3',4'-methylenedioxy-a-pyrrolidinopropiophenone (MDPPP), a novel designer drug, to its demethylenated major metabolite 3',4'-dihydroxy-pyrrolidinopropiophenone (di-HO-PPP) was studied in pooled human liver microsomes (HLM) and in cDNA-expressed human hepatic cytochrome P450 (CYP) enzymes. CYP2C19 catalysed the demethylenation with apparent Km and Vmax values of 120.0+/-13.4 microM and 3.2+/-0.1 pmol/min/pmol CYP, respectively (mean+/-standard deviation). CYP2D6 catalysed the demethylenation with apparent Km and Vmax values of 13.5+/-1.5 microM and 1.3+/-0.1 pmol/min/pmol CYP, respectively. HLM exhibited a clear biphasic profile with an apparent Km,1 value of 7.6+/-9.0 and a Vmax,1 value of 11.1+/-3.6 pmol/min/mg protein, respectively. Percentages of intrinsic clearances of MDPPP by specific CYPs were calculated using the relative activity factor (RAF) approach with (S)-mephenytoin-4'-hydroxylation or bufuralol-1'-hydroxylation as index reactions for CYP2C19 or CYP2D6, respectively. MDPPP, di-HO-PPP and the standard 4'-methyl-pyrrolidinohexanophenone (MPHP) were separated and analysed by liquid chromatography-mass spectrometry in the selected-ion monitoring (SIM) mode. The CYP2D6-specific chemical inhibitor quinidine (3 microM) significantly (p<0.001) inhibited di-HO-PPP formation by 75.8%+/-1.7% (mean+/-standard error of the mean) in incubation mixtures with HLM and 2 microM MDPPP. It can be concluded from the data obtained from kinetic and inhibition studies that polymorphically expressed CYP2D6 and CYP2C19 are almost equally responsible for MDPPP demethylenation.
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Affiliation(s)
- D Springer
- Department of Experimental and Clinical Toxicology, University of Saarland, D-66421 Bomburg (Saar), Germany
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13
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Maurer HH. Chapter 12 Forensic screening with GC-MS. ACTA ACUST UNITED AC 2008. [DOI: 10.1016/s1567-7192(06)06012-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
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14
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Hunek C, Burgyan M, Wang S. Measurement of 10,11-dihydro-10-hydroxy-carbamazepine in serum and plasma by high-performance liquid chromatography. Clin Chem Lab Med 2008; 46:1429-33. [DOI: 10.1515/cclm.2008.276] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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15
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Development and validation of a LC/MS/MS method for simultaneous quantification of oxcarbazepine and its main metabolites in human serum. J Chromatogr B Analyt Technol Biomed Life Sci 2007; 860:153-9. [DOI: 10.1016/j.jchromb.2007.10.025] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2007] [Revised: 10/10/2007] [Accepted: 10/15/2007] [Indexed: 11/17/2022]
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16
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Peters FT, Meyer MR, Theobald DS, Maurer HH. Identification of Cytochrome P450 Enzymes Involved in the Metabolism of the New Designer Drug 4′-Methyl-α-pyrrolidinobutyrophenone. Drug Metab Dispos 2007; 36:163-8. [DOI: 10.1124/dmd.107.017293] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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17
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de Sousa Maia MB, do Nascimento DF, Martins IL, Cunha AN, de Lima FEG, Bezerra FAF, de Moraes MO, de Moraes MEA. Simultaneous quantitative analysis of oxcarbazepine and 10,11-dihydro-10-hydroxycarbamazepine in human plasma by liquid chromatography–electrospray tandem mass spectrometry. J Pharm Biomed Anal 2007; 45:304-11. [PMID: 17869472 DOI: 10.1016/j.jpba.2007.08.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2007] [Revised: 07/30/2007] [Accepted: 08/02/2007] [Indexed: 11/24/2022]
Abstract
A fast and sensitive method to quantify oxcarbazepine (OXC) and its active metabolite, 10,11-dihydro-10-hydroxycarbamazepine (MHD) in human plasma using HPLC-MS/MS has been developed. The method involved liquid-liquid extraction (LLE), with diethyl ether-diclhoromethane (60:40v/v) using deuterade carbamazepine (d10-carbamazepine) as internal standard (IS). The analytes and IS were separated using an isocratic mobile phase (acetonitrile/water (50:50v/v)+20 mM acetic acid) on the analytical column Phenomenex Luna C18 5 microm (150 mm x 4.6 mm) at room temperature. Detection was performed by a Micromass Quatro LC mass spectrometer in the reaction monitoring mode using positive electrospray ionization (ESI+). The MS-MS ion transition monitored were m/z 253>208 for OXC, m/z 255>194 for MHD and m/z 247>204 for IS. Over the range 20-5250 ng/ml for OXC and 40-10,500 ng/ml for MHD, the calibration curves were defined by the following equations: y = 0.00568 + 0.00296x -5.70e - 8x(2) and y = 0.00749 + 0.00178x - 5.70e - 8x(2) for OXC and MHD, respectively. All coefficient of determination (r(2)) were close to unity (0.9986-0.9994). The lower limits of quantification obtained as a result of the LLE procedure was 20 ng/ml for OXC and 40 ng/ml for MHD. The statistical evaluation of the developed method was conducted by examining within-batch and between-batch precision data, which were within the required limits. The suitability of the assay for pharmacokinetics studies was determined by measuring OXC and MHD concentration after administration of a single 10 ml of OXC oral suspension (6%) in plasma human of healthy volunteers.
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Affiliation(s)
- Maria Bernadete de Sousa Maia
- Department of Physiology and Pharmacology, Federal University of Pernambuco, Av. Prof. Moraes Rêgo S/N, Cidade Universitária, 50670-901 Recife, Pernambuco, Brazil.
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18
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Mazzucchelli I, Franco V, Fattore C, Marchiselli R, Perucca E, Gatti G. A Novel Enantioselective Microassay for the High-Performance Liquid Chromatography Determination of Oxcarbazepine and Its Active Metabolite Monohydroxycarbazepine in Human Plasma. Ther Drug Monit 2007; 29:319-24. [PMID: 17529889 DOI: 10.1097/ftd.0b013e318058a2c2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A simple and innovative assay is described that allows the determination of the antiepileptic drug oxcarbazepine and the chiral separation of the two enantiomers of its active metabolite monohydroxycarbazepine (licarbazepine). The assay requires liquid-liquid extraction of the sample (200 microL) into tert-butyl methyl ether and dichloromethane, drying of the organic phase under a nitrogen stream, reconstitution with the mobile phase, and injection in the high-performance liquid chromatography system after filtering. Separation of oxcarbazepine, R-(-)-monohydroxycarbazepine, S-(+)-monohydroxycarbazepine, and the second-step metabolite 10,11-trans-dihydroxycarbamazepine (racemate) is achieved with a Chiralcel ODR column and potassium hexafluorophosphate/acetonitrile as mobile phase. Detection is by ultraviolet absorbance at 210 nm. Standard curves are linear (r2 > or = 0.999) over the range of 0.1 to 25 microg/mL for each analyte with a limit of quantification of 0.1 microg/mL (1 ng injected) for all compounds. Within-day and between-day precision is better than 12% and within-day and between-day accuracy is between 99% and 116% for each compound. These performance characteristics are adequate for pharmacokinetic studies and for therapeutic drug monitoring. However, because the two enantiomers of monohydroxycarbazepine exhibit similar pharmacologic activity, nonenantioselective assays are likely to be more cost-effective for therapeutic drug monitoring purposes.
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Affiliation(s)
- Iolanda Mazzucchelli
- Clinical Pharmacology Unit, Department of Internal Medicine and Therapeutics, University of Pavia, Pavia, Italy
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Beyer J, Peters FT, Kraemer T, Maurer HH. Detection and validated quantification of toxic alkaloids in human blood plasma--comparison of LC-APCI-MS with LC-ESI-MS/MS. JOURNAL OF MASS SPECTROMETRY : JMS 2007; 42:621-33. [PMID: 17323418 DOI: 10.1002/jms.1191] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Poisonings with toxic plants may occur after abuse, intentional or accidental ingestion of plants. For diagnosis of such poisonings, multianalyte procedures were developed for detection and validated quantification of the toxic alkaloids aconitine, atropine, colchicine, coniine, cytisine, nicotine and its metabolite cotinine, physostigmine, and scopolamine in plasma using LC-APCI-MS and LC-ESI-MS/MS. After mixed-mode solid-phase extraction of 1 ml of plasma, the analytes were separated using a C8 base select separation column and gradient elution (acetonitrile/ammonium formate, pH 3.5). Calibration curves were used for quantification with cotinine-d(3), benzoylecgonine-d(3), and trimipramine-d(3) as internal standards. The method was validated according to international guidelines. Both assays were selective for the tested compounds. No instability was observed after repeated freezing and thawing or in processed samples. The assays were linear for coniine, cytisine, nicotine and its metabolite cotinine, from 50 to 1000 ng/ml using LC-APCI-MS and 1 to 1000 ng/ml using LC-ESI-MS/MS, respectively, and for aconitine, atropine, colchicine, physostigmine, and scopolamine from 5 to 100 ng/ml for LC-APCI-MS and 0.1 to 100 ng/ml for LC-ESI-MS/MS, respectively. Accuracy ranged from -38.6 to 14.0%, repeatability from 2.5 to 13.5%, and intermediate precision from 4.8 to 13.5% using LC-APCI-MS and from -38.3 to 8.3% for accuracy, from 3.5 to 13.8%, for repeatability, and from 4.3 to 14.7% for intermediate precision using LC-ESI-MS/MS. The lower limit of quantification was fixed at the lowest calibrator in the linearity experiments. With the exception of the greater sensitivity and higher identification power, LC-ESI-MS/MS had no major advantages over LC-APCI-MS. Both presented assays were applicable for sensitive detection of all studied analytes and for accurate and precise quantification, with the exception of the rather volatile nicotine. The applicability of the assays was demonstrated by analysis of plasma samples from suspected poisoning cases.
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Affiliation(s)
- Jochen Beyer
- Department of Experimental and Clinical Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, Saarland University, D-66421 Homburg (Saar), Germany
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Peters FT. Stability of analytes in biosamples - an important issue in clinical and forensic toxicology? Anal Bioanal Chem 2007; 388:1505-19. [PMID: 17429615 DOI: 10.1007/s00216-007-1267-2] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2007] [Revised: 03/15/2007] [Accepted: 03/16/2007] [Indexed: 10/23/2022]
Abstract
Knowledge of the stability of drugs in biological samples is important for the interpretation of toxicological findings. This paper reviews data on the stability of drugs in blood, plasma, or serum. Since such data have already been reviewed for classic drugs of abuse, the focus here is on newer drugs of abuse and on therapeutic drugs. Key information about the conditions of the stability experiments will be provided and the following drugs or drug classes are covered: amphetamines, amphetamine-derived, piperazine-derived, and phenethylamine-derived designer drugs, antidepressants, neuroleptics, anti-HIV drugs, antiepileptics, cardiovascular drugs, and others. In addition, aspects of stability experiments and their evaluations are discussed. The data presented show that the majority of drugs are stable in blood, plasma, or serum samples under the conditions usually encountered in a clinical or forensic toxicology laboratory. Instability usually only occurs for drugs carrying ester moieties, sulfur atoms, or other easily oxidized or reduced structures. Nevertheless, clinical or forensic specimens should always be stored at least in the refrigerator and preferably at -20 degrees C or lower to avoid any degradation. Finally, results obtained from biosamples that have been stored at room temperature for a longer time should be interpreted with great care and partial degradation should always be considered.
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Affiliation(s)
- Frank T Peters
- Department of Experimental and Clinical Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, Saarland University, Homburg (Saar), Germany.
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21
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Corso G, D'Apolito O, Paglia G. The accuracy of oxcarbazepine (OXC) quantification by a liquid chromatography/tandem mass spectrometry method is influenced by the ion source fragmentation of its metabolite trans-diol-carbazepine (DHD). RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2007; 21:269-72. [PMID: 17167814 DOI: 10.1002/rcm.2821] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
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22
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Kimiskidis V, Spanakis M, Niopas I, Kazis D, Gabrieli C, Kanaze FI, Divanoglou D. Development and validation of a high performance liquid chromatographic method for the determination of oxcarbazepine and its main metabolites in human plasma and cerebrospinal fluid and its application to pharmacokinetic study. J Pharm Biomed Anal 2007; 43:763-8. [PMID: 16959463 DOI: 10.1016/j.jpba.2006.07.047] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2006] [Accepted: 07/27/2006] [Indexed: 11/26/2022]
Abstract
An isocratic reversed-phase HPLC-UV procedure for the determination of oxcarbazepine and its main metabolites 10-hydroxy-10,11-dihydrocarbamazepine and 10,11-dihydroxy-trans-10,11-dihydrocarbamazepine in human plasma and cerebrospinal fluid has been developed and validated. After addition of bromazepam as internal standard, the analytes were isolated from plasma and cerebrospinal fluid by liquid-liquid extraction. Separation was achieved on a X-TERRA C18 column using a mobile phase composed of 20 mM KH(2)PO(4), acetonitrile, and n-octylamine (76:24:0.05, v/v/v) at 40 degrees C and detected at 237 nm. The described assay was validated in terms of linearity, accuracy, precision, recovery and lower limit of quantification according to the FDA validation guidelines. Calibration curves were linear with a coefficient of variation (r) greater than 0.998. Accuracy ranged from 92.3% to 106.0% and precision was between 2.3% and 8.2%. The method has been applied to plasma and cerebrospinal fluid samples obtained from patients treated with oxcarbazepine, both in monotherapy and adjunctive therapy.
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Affiliation(s)
- Vasilios Kimiskidis
- 3rd Department of Neurology, George Papanicolaou Hospital, Aristotle University of Thessaloniki, Greece
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Maurer HH. Hyphenated mass spectrometric techniques-indispensable tools in clinical and forensic toxicology and in doping control. JOURNAL OF MASS SPECTROMETRY : JMS 2006; 41:1399-413. [PMID: 17051522 DOI: 10.1002/jms.1112] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Hyphenated mass spectrometric techniques, particularly gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/mass spectrometry (LC/MS), are indispensable tools in clinical and forensic toxicology and in doping control owing to their high sensitivity and specificity. They are used for screening, library-assisted identification and quantification of drugs, poisons and their metabolites, prerequisites for competent expertise in these fields. In addition, they allow the study of metabolism of new drugs or poisons as a basis for developing screening procedures in biological matrices, most notably in urine, or toxicological risk assessment. Concepts and procedures using GC/MS and LC/MS techniques in the areas of analytical toxicology and the role of mass spectral libraries are presented and discussed in this feature article. Finally, perspectives of their future position are discussed.
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Affiliation(s)
- Hans H Maurer
- Department of Experimental and Clinical Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, University of Saarland, D-66421 Homburg (Saar), Germany.
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Lanckmans K, Clinckers R, Van Eeckhaut A, Sarre S, Smolders I, Michotte Y. Use of microbore LC-MS/MS for the quantification of oxcarbazepine and its active metabolite in rat brain microdialysis samples. J Chromatogr B Analyt Technol Biomed Life Sci 2005; 831:205-12. [PMID: 16386473 DOI: 10.1016/j.jchromb.2005.12.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2005] [Revised: 10/24/2005] [Accepted: 12/05/2005] [Indexed: 11/18/2022]
Abstract
A microbore LC-MS/MS method is developed and validated for the quantification of the anti-epileptic drug oxcarbazepine (OXC) and its active metabolite 10,11-dihydro-10-hydroxycarbamazepine (MHD) in rat brain microdialysates, together with the internal standard for microdialysis probe calibration, 2-methyl-5H-dibenz(b,f)azepine-5-carboxamide (m-CBZ). The benefits of gradient versus isocratic separation are shown, next to the improved sensitivity resulting from the addition of 0.1% formic acid to the mobile phase. The coupling of microdialysis with ESI-MS requires sample desalting for which column switching was applied. Using weighed regression to calculate the calibration curves (1-1000 ng/mL), the assay was validated in terms of linearity, accuracy and precision, yielding a sensitive (limit of quantification is 1 ng/mL) and selective method for quantification of OXC, MHD and m-CBZ. By applying this method, we were able to determine the extracellular concentrations of OXC and MHD during at least 4h after intraperitoneal (i.p.) administration of 10 mg/kg OXC.
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Affiliation(s)
- Katrien Lanckmans
- Department of Pharmaceutical Chemistry, Drug Analysis and Drug Information, Research Group Experimental Pharmacology, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium
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Maurer HH. Multi-analyte procedures for screening for and quantification of drugs in blood, plasma, or serum by liquid chromatography-single stage or tandem mass spectrometry (LC-MS or LC-MS/MS) relevant to clinical and forensic toxicology. Clin Biochem 2005; 38:310-8. [PMID: 15766732 DOI: 10.1016/j.clinbiochem.2005.01.014] [Citation(s) in RCA: 145] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2004] [Accepted: 01/17/2005] [Indexed: 11/17/2022]
Abstract
This paper reviews multi-analyte procedures for screening and quantification of drugs in blood, plasma, or serum using liquid chromatography coupled with a single stage or tandem mass spectrometer (LC-MS, LC-MS/MS). These procedures are relevant tools in clinical and forensic toxicology, and cover analysis of amphetamines, cocaine, hallucinogens, opioids, anesthetics, hypnotics, benzodiazepines, antidepressants, neuroleptics, antihistamines, sulfonylurea-type antidiabetics, beta-blockers, and other cardiac drugs. Basic information on the procedures is given in two tables and multi-analyte screening, identification, and quantification are illustrated in three figures. A critical discussion on the pros and cons of such LC-MS procedures is also included.
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Affiliation(s)
- Hans H Maurer
- Department of Experimental and Clinical Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, University of Saarland, D-66421 Homburg (Saar), Germany.
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Maurer HH. Advances in analytical toxicology: the current role of liquid chromatography?mass spectrometry in drug quantification in blood and oral fluid. Anal Bioanal Chem 2004; 381:110-8. [PMID: 15309372 DOI: 10.1007/s00216-004-2774-z] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2004] [Revised: 07/13/2004] [Accepted: 07/14/2004] [Indexed: 10/26/2022]
Abstract
This paper reviews procedures for quantification of drugs in the biosamples blood, plasma, serum, or oral fluid (saliva, etc.) using liquid chromatography coupled with single-stage or tandem mass spectrometry (LC-MS, LC-MS-MS). Such procedures are important prerequisites for competent toxicological judgment and consultation in clinical and forensic toxicology. They cover blood (plasma, serum) analysis of amphetamines and related designer drugs, anesthetics, anticonvulsants, benzodiazepines, opioids, serotonergic drugs, tricyclic antidepressants, neuroleptics, antihistamines, beta-blockers, muscle relaxants, and sulfonylurea-type antidiabetics, and oral fluid analysis of amphetamines and related designer drugs, cocaine, benzoylecgonine, codeine, morphine, enantiomers of methadone and its main metabolite 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), the nicotine metabolites cotinine and hydroxycotinine, and finally risperidone and its metabolite 9-hydroxyrisperidone. Basic information on the procedures is given in two tables and an example of quantification is illustrated in two figures. The pros and cons of such LC-MS procedures including sample work-up and ion suppression effects are critically discussed.
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Affiliation(s)
- Hans H Maurer
- Department of Experimental and Clinical Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, University of Saarland, 66421 Homburg (Saar), Germany.
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Springer D, Staack RF, Paul LD, Kraemer T, Maurer HH. Identification of cytochrome P450 enzymes involved in the metabolism of 4'-methoxy-alpha-pyrrolidinopropiophenone (MOPPP), a designer drug, in human liver microsomes. Xenobiotica 2004; 33:989-98. [PMID: 14555336 DOI: 10.1080/00498250310001602775] [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: 10/26/2022]
Abstract
1. The metabolism of 4'-methoxy-alpha-pyrrolidinopropiophenone (MOPPP), a novel designer drug, to its demethylated major metabolite 4'-hydroxy-pyrrolidinopropio-phenone (HO-PPP) was studied in pooled human liver microsomes (HLM) and in cDNA-expressed human hepatic cytochrome P450 (CYP) enzymes. 2. CYP2C19 catalysed the demethylation with apparent Km and Vmax values of 373.4 +/- 45.1 microM and 6.0 +/- 0.3 pmol min(-1) pmol(-1) CYP, respectively (mean +/- SD). Both CYP2D6 and HLM exhibited clear biphasic profiles with apparent K(m,1) values of 1.3 +/- 0.4 and 22.0 +/- 6.5 microM, respectively, and V(max,1) values of 1.1 +/- 0.1 pmol min(-1) pmol(-1) CYP and 169.1 +/- 20.5 pmol min(-1) mg(-1) protein, respectively. 3. Percentages of intrinsic clearances of MOPPP by particular CYPs were calculated using the relative activity factor (RAF) approach with (S)-mephenytoin-4'-hydroxylation or bufuralol-1'-hydroxylation as index reactions for CYP2C19 or CYP2D6, respectively. 4. MOPPP, HO-PPP and the standard 3',4'-methylenedioxy-pyrrolidinopropio-phenone (MDPPP) were separated and analysed by liquid chromatography-mass spectrometry in the selected-ion monitoring (SIM) mode. 5. The CYP2D6 specific chemical inhibitor quinidine (3 microM) significantly (p<0.0001) inhibited HO-PPP formation by 91.8 +/- 0.5% (mean +/- SEM) in incubation mixtures with HLM and 2 microM MOPPP. 6. It can be concluded from the data obtained from kinetic and inhibition studies that polymorphically expressed CYP2D6 is the enzyme mainly responsible for MOPPP demethylation.
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Affiliation(s)
- D Springer
- Department of Experimental and Clinical Toxicology, University of Saarland, Homburg (Saar), Germany
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Staack RF, Paul LD, Springer D, Kraemer T, Maurer HH. Cytochrome P450 dependent metabolism of the new designer drug 1-(3-trifluoromethylphenyl)piperazine (TFMPP). Biochem Pharmacol 2004; 67:235-44. [PMID: 14698036 DOI: 10.1016/j.bcp.2003.08.029] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
1-(3-Trifluoromethylphenyl)piperazine (TFMPP) is a designer drug with serotonergic properties. Previous studies with male Wistar rats (WI) had shown, that TFMPP was metabolized mainly by aromatic hydroxylation. In the current study, it was examined whether this reaction may be catalyzed by cytochrome P450 (CYP)2D6 by comparing TFMPP vs. hydroxy TFMPP ratios in urine from female Dark Agouti rats, a model of the human CYP2D6 poor metabolizer phenotype (PM), male Dark Agouti rats, an intermediate model, and WI, a model of the human CYP2D6 extensive metabolizer phenotype. Furthermore, the human hepatic CYPs involved in TFMPP hydroxylation were identified using cDNA-expressed CYPs and human liver microsomes. Finally, TFMPP plasma levels in the above mentioned rats were compared. The urine studies suggested that TFMPP hydroxylation might be catalyzed by CYP2D6 in humans. Studies using human CYPs showed that CYP1A2, CYP2D6 and CYP3A4 catalyzed TFMPP hydroxylation, with CYP2D6 being the most important enzyme accounting for about 81% of the net intrinsic clearance, calculated using the relative activity factor approach. The hydroxylation was significantly inhibited by quinidine (77%) and metabolite formation in poor metabolizer genotype human liver microsomes was significantly lower (63%) compared to pooled human liver microsomes. Analysis of the plasma samples showed that female Dark Agouti rats exhibited significantly higher TFMPP plasma levels compared to those of male Dark Agouti rats and WI. Furthermore, pretreatment of WI with the CYP2D inhibitor quinine resulted in significantly higher TFMPP plasma levels. In conclusion, the presented data give hints for possible differences in pharmacokinetics in human PM and human CYP2D6 extensive metabolizer phenotype subjects relevant for risk assessment.
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Affiliation(s)
- Roland F Staack
- Department of Experimental and Clinical Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, University of Saarland, D-66421 (Saar), Homburg, Germany
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Springer D, Paul LD, Staack RF, Kraemer T, Maurer HH. Identification of cytochrome p450 enzymes involved in the metabolism of 4'-methyl-alpha-pyrrolidinopropiophenone, a novel scheduled designer drug, in human liver microsomes. Drug Metab Dispos 2003; 31:979-82. [PMID: 12867484 DOI: 10.1124/dmd.31.8.979] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
4'-Methyl-alpha-pyrrolidinopropiophenone (MPPP) is a new drug of abuse. It is believed to have an abuse potential similar to that of amphetamines. Previous studies with Wistar rats had shown that MPPP was metabolized mainly by hydroxylation in position 4' followed by dehydrogenation to the corresponding carboxylic acid. The aim of the study presented here was to identify the human hepatic cytochrome p450 (p450) enzymes involved in the biotransformation of MPPP to 4'-hydroxymethyl-pyrrolidinopropiophenone. Baculovirus-infected insect cell microsomes and human liver microsomes were used for this purpose. Only CYP2C19 and CYP2D6 catalyzed this hydroxylation. The apparent Km and Vmax values for the latter were 9.8 +/- 2.5 microM and 13.6 +/- 0.7 pmol/min/pmol p450, respectively. CYP2C19 was not saturable over the tested substrate range (2-1000 microM) and interestingly showed a biphasic kinetic profile with apparent Km,1 and Vmax,1 values of 47.2 +/- 12.5 microM and 8.1 +/- 1.4 pmol/min/pmol p450, respectively. Experiments with pooled human liver microsomes also revealed biphasic nonsaturable kinetics with apparent Km,1 and Vmax,1 values of 57.0 +/- 20.9 microM and 199.7 +/- 59.7 pmol/min/mg of protein for the high affinity enzyme, respectively. Incubation of 2 microM MPPP with 3 microM of the CYP2D6-specific inhibitor quinidine resulted in significant (p < 0.01) turnover inhibition (11.8 +/- 1.6% of control). Based on kinetic data corrected for the relative activity factors, CYP2D6 is the enzyme mainly responsible for MPPP hydroxylation, confirmed by CYP2D6 inhibition studies.
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Affiliation(s)
- Dietmar Springer
- Department of Experimental and Clinical Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, University of Saarland, Building 46, D-66421 Homburg (Saar), Germany
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Kratzsch C, Peters FT, Kraemer T, Weber AA, Maurer HH. Screening, library-assisted identification and validated quantification of fifteen neuroleptics and three of their metabolites in plasma by liquid chromatography/mass spectrometry with atmospheric pressure chemical ionization. JOURNAL OF MASS SPECTROMETRY : JMS 2003; 38:283-295. [PMID: 12644990 DOI: 10.1002/jms.440] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A liquid chromatographic/mass spectrometric assay with atmospheric pressure chemical ionization (APCI-LC/MS) is presented for the fast and reliable screening and identification and for the precise and sensitive quantification of 15 neuroleptic (antipsychotic) drugs and three of their relevant metabolites in plasma. It allows confirmation of the diagnosis of a neuroleptic overdose and monitoring of psychiatric patients' compliance. The neuroleptics amisulpride, bromperidol, clozapine, droperidol, flupenthixol, fluphenazine, haloperidol, melperone, olanzapine, perazine, pimozide, risperidone, sulpiride, zotepine and zuclopenthixol and the pharmacologically active metabolites norclozapine, clozapine N-oxide and 9-hydroxyrisperidone were extracted from plasma using solid-phase extraction and were separated on a Merck LiChroCART column with Superspher 60 RP Select B as the stationary phase. Gradient elution was performed using aqueous ammonium formate and acetonitrile. After screening and identification in the scan mode using the authors' new LC/MS library, the neuroleptics were quantified in the selected-ion mode. The quantification assay was fully validated. It was found to be selective and proved to be linear from sub-therapeutic to over therapeutic concentrations for all analytes. The corresponding reference levels are listed. The accuracy and precision data were within the required limits. The analytes were stable in frozen plasma for at least 1 month. The method was successfully applied to several authentic plasma samples from patients treated or intoxicated with various neuroleptics. The validated LC/MS assay has proved to be appropriate for the isolation, separation, screening, identification and quantification of various neuroleptics in plasma for clinical toxicology and therapeutic drug monitoring purposes.
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Affiliation(s)
- Carsten Kratzsch
- Department of Experimental and Clinical Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, University of Saarland, D-66421 Homburg (Saar), Germany
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