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Li J, Zhang J, Liu H, Wu L. A comparative study of primary secondary amino (PSA) and multi-walled carbon nanotubes (MWCNTs) as QuEChERS absorbents for the rapid determination of diazepam and its major metabolites in fish samples by high-performance liquid chromatography-electrospray ionisation-tandem mass spectrometry. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2016; 96:555-560. [PMID: 25652266 DOI: 10.1002/jsfa.7123] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 01/26/2015] [Accepted: 01/27/2015] [Indexed: 06/04/2023]
Abstract
BACKGROUND A simple and fast modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method is presented for the determination of diazepam and its three major metabolites, nordiazepam, temazepam and oxazepam (benzodiazepines) in fish samples by liquid chromatography-electrospray ionisation-tandem mass spectrometry. RESULTS Muscle tissues were extracted with acetonitrile, and then cleaned with primary secondary amino (PSA) adsorbents. The cleanup effect of PSA was compared with that of multi-walled carbon nanotubes (MWCNTs) in term of extraction efficiency. The better results were obtained when PSA was used. The chromatography separation was achieved within 5.0 min on a C18 column. The limit of detection was 0.5 µg kg(-1) and the limit of quantification was 2.5 µg kg(-1). Average recoveries of diazepam and its main metabolites were in the range of 88.5-110.1%, with a relative standard deviation lower than 10.0%. CONCLUSION The proposed method for fish samples gives good recoveries, linearity, precision and accuracy.
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Affiliation(s)
- Jincheng Li
- Chinese Academy of Fishery Sciences, Quality and Standard Research Center, Beijing 100141, People's Republic of China
| | - Jing Zhang
- Chinese Academy of Fishery Sciences, Quality and Standard Research Center, Beijing 100141, People's Republic of China
| | - Huan Liu
- Chinese Academy of Fishery Sciences, Quality and Standard Research Center, Beijing 100141, People's Republic of China
| | - Lidong Wu
- Chinese Academy of Fishery Sciences, Quality and Standard Research Center, Beijing 100141, People's Republic of China
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Martindale SM, Powers RH, Bell SC. Simultaneous quantification of diazepam, flunitrazepam and metabolites in reinforced clostridial medium by liquid chromatography-tandem mass spectrometry. J Anal Toxicol 2014; 39:29-34. [PMID: 25313386 DOI: 10.1093/jat/bku110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A novel liquid chromatography-tandem mass spectrometry method was validated for identification and quantification of diazepam, flunitrazepam and metabolites in reinforced clostridial medium (RCM), a complex matrix used to provide the nutrients required for bacterial growth. The method was designed for subsequent use in the investigation of gastrointestinal bacteria as a potential source of postmortem alteration of drugs of abuse and respective metabolite concentrations. A literature review yielded no experimental means or model for the extraction and analysis of samples from RCM or similar bacterial medium. Development and validation of a new experimental method were therefore critical. In future work, this method could be adapted and extended to similar organic compounds of interest. The calibration curves extended from 0.100 to 500 ng/mL. Analyte recoveries ranged from 95 to 119% and matrix effects from 97 to 119%. Bias was ≤±17.6%, within-run precision ≤12.2%, and between-run precision ≤11.7% across all concentration levels. The limits of detection and quantitation ranged from 0.100 to 1 ng/mL. Dilution integrity was maintained for 1:2 and 1:5 dilutions. Analytes were stable through two freeze-thaw cycles and processed samples for 48 h. Method robustness was evaluated by changes in buffer composition and column temperature as well as samples prepared by an alternate analyst.
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Affiliation(s)
- Stephanie M Martindale
- Edgewood Chemical Biological Center, E3400 Ricketts Point Road, Aberdeen Proving Ground, Gunpowder, MD 21010, USA
| | - Robert H Powers
- Connecticut DPS Controlled Substances and Toxicology Laboratory, 278 Colony Street, Meriden, CT 06451, USA
| | - Suzanne C Bell
- Department of Chemistry, West Virginia University, 1600 University Avenue, 208 Oglebay Hall, Morgantown, WV 26508, USA
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3
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Yuan Q, Liao Z, Wang F, Zhang H, Guo Y, Li R. A RAPID HILIC METHOD FOR ANALYSIS OF DIAZEPAM AND ESTAZOLAM IN HUMAN PLASMA. J LIQ CHROMATOGR R T 2013. [DOI: 10.1080/10826076.2012.678459] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Qin Yuan
- a Engineering Research Center of Eco-Environment in Three Gorges Reservoir Region, Ministry of Education , China Three Gorges University , Yichang , China
| | - Zhaojiang Liao
- a Engineering Research Center of Eco-Environment in Three Gorges Reservoir Region, Ministry of Education , China Three Gorges University , Yichang , China
| | - Fengling Wang
- b Hospital of China Three Gorges University , Yichang , China
| | - Huilian Zhang
- c Research Institute of Criminal Science and Technology , Yichang Municipal Public Security Bureau , Yichang , China
| | - Yali Guo
- a Engineering Research Center of Eco-Environment in Three Gorges Reservoir Region, Ministry of Education , China Three Gorges University , Yichang , China
| | - Ruiping Li
- a Engineering Research Center of Eco-Environment in Three Gorges Reservoir Region, Ministry of Education , China Three Gorges University , Yichang , China
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4
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Han S, Jia S, Guo L. Flow-injection chemiluminescence determination of diazepam by oxidation withN-bromosuccinimide. LUMINESCENCE 2012; 28:888-93. [DOI: 10.1002/bio.2452] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2012] [Revised: 09/18/2012] [Accepted: 10/18/2012] [Indexed: 11/06/2022]
Affiliation(s)
- Suqin Han
- School of Chemistry and Material Science; Shanxi Normal University; Linfen 041004 P.R. China
| | - Shize Jia
- School of Chemistry and Material Science; Shanxi Normal University; Linfen 041004 P.R. China
| | - Liang Guo
- School of Chemistry and Material Science; Shanxi Normal University; Linfen 041004 P.R. China
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5
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Benzodiazepines: sample preparation and HPLC methods for their determination in biological samples. Bioanalysis 2011; 1:755-84. [PMID: 21083137 DOI: 10.4155/bio.09.43] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Benzodiazepines (BDZs) belong to a group of substances known for their sedative, antidepressive, muscle relaxant, tranquilizer, hypnotic and anticonvulsant properties. Their determination in biological fluids is essential in clinical assays as well as in forensics and toxicological studies. Researchers focus on the development of rapid, accurate, precise and sensitive methods for the determination of BDZs and their metabolites. A large number of analytical methods using different techniques have been reported, but none can be considered as the method of choice. BDZs are usually present at trace levels (microgram or nanogram per milliliter) in a complex biological matrix and the potentially interfering compounds must be isolated by various extraction techniques before analysis. An extended and comprehensive review is presented herein, focusing on sample preparation (pretreatment and extraction) and HPLC conditions applied by different authors. These methods enable bioanalysts to achieve detection limits down to 1-2 ng/ml using UV/diode array detection, readily available in most laboratories, and better than 1 ng/ml using electron capture detection, which is lower than that obtained using a nitrogen phosphorus detector. MS interfaced with electrospray ionization offered a similar sensitivity, while negative chemical ionization MS or sonic spray ionization MS provided sensitivity down to 0.1 ng/ml.
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6
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Nakamura M. Analyses of benzodiazepines and their metabolites in various biological matrices by LC-MS(/MS). Biomed Chromatogr 2011; 25:1283-307. [DOI: 10.1002/bmc.1598] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2010] [Revised: 11/15/2010] [Accepted: 11/23/2010] [Indexed: 01/01/2023]
Affiliation(s)
- Mitsuhiro Nakamura
- Laboratory of Drug Informatics; Gifu Pharmaceutical University; 1-25-4, daigaku-nishi; Gifu; 501-1196; Japan
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7
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SUN L, ZHANG L, XU Q, WANG S, WANG X. Determination of ten sedative residues in pork and kidney by ultra performance liquid chromatography-tandem mass spectrometry. Se Pu 2010; 28:38-42. [DOI: 10.3724/sp.j.1123.2010.00038] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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8
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A new approach to the application of solid phase extraction disks with LC–MS/MS for the analysis of drugs on a 96-well plate format. J Pharm Biomed Anal 2009; 50:556-62. [DOI: 10.1016/j.jpba.2008.07.014] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2008] [Accepted: 07/17/2008] [Indexed: 11/18/2022]
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9
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Nakamura M, Ohmori T, Itoh Y, Terashita M, Hirano K. Simultaneous determination of benzodiazepines and their metabolites in human serum by liquid chromatography-tandem mass spectrometry using a high-resolution octadecyl silica column compatible with aqueous compounds. Biomed Chromatogr 2009; 23:357-64. [DOI: 10.1002/bmc.1122] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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10
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Design of packed-fiber solid-phase extraction device for analysis of the drug and its metabolite in plasma. Biomed Microdevices 2009; 11:723-9. [DOI: 10.1007/s10544-009-9285-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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11
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Mutlib AE. Application of stable isotope-labeled compounds in metabolism and in metabolism-mediated toxicity studies. Chem Res Toxicol 2008; 21:1672-89. [PMID: 18702535 DOI: 10.1021/tx800139z] [Citation(s) in RCA: 136] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Stable isotope-labeled compounds have been synthesized and utilized by scientists from various areas of biomedical research during the last several decades. Compounds labeled with stable isotopes, such as deuterium and carbon-13, have been used effectively by drug metabolism scientists and toxicologists to gain better understanding of drugs' disposition and their potential role in target organ toxicities. The combination of stable isotope-labeling techniques with mass spectrometry and nuclear magnetic resonance (NMR) spectroscopy, which allows rapid acquisition and interpretation of data, has promoted greater use of these stable isotope-labeled compounds in absorption, distribution, metabolism, and excretion (ADME) studies. Examples of the use of stable isotope-labeled compounds in elucidating structures of metabolites and delineating complex metabolic pathways are presented in this review. The application of labeled compounds in mechanistic toxicity studies will be discussed by providing an example of how strategic placement of a deuterium atom in a drug molecule mitigated specific-specific renal toxicity. Other examples from the literature demonstrating the application of stable isotope-labeled compounds in understanding metabolism-mediated toxicities are presented. Furthermore, an example of how a stable isotope-labeled compound was utilized to better understand some of the gene changes in toxicogenomic studies is discussed. The interpretation of large sets of data produced from toxicogenomics studies can be a challenge. One approach that could be used to simplify interpretation of the data, especially from studies designed to link gene changes with the formation of reactive metabolites thought to be responsible for toxicities, is through the use of stable isotope-labeled compounds. This is a relatively unexplored territory and needs to be further investigated. The employment of analytical techniques, especially mass spectrometry and NMR, used in conjunction with stable isotope-labeled compounds to establish and understand mechanistic link between reactive metabolite formation, genomic, and proteomic changes and onset of toxicity is proposed. The use of stable isotope-labeled compounds in early human ADME studies as a way of identifying and possibly quantifying all drug-related components present in systemic circulation is suggested.
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Affiliation(s)
- Abdul E Mutlib
- Biotransformation Department, Drug Safety and Metabolism, Wyeth Research, Collegeville, Pennsylvania 19426, USA.
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12
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Honda A, Suzuki Y, Suzuki K. Review of molecular modification techniques for improved detection of biomolecules by mass spectrometry. Anal Chim Acta 2008; 623:1-10. [DOI: 10.1016/j.aca.2008.05.064] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2008] [Revised: 04/27/2008] [Accepted: 05/27/2008] [Indexed: 12/21/2022]
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13
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Pirnay S, Hervé F, Bouchonnet S, Perrin B, Baud FJ, Ricordel I. Liquid chromatographic-electrospray ionization mass spectrometric quantitative analysis of buprenorphine, norbuprenorphine, nordiazepam and oxazepam in rat plasma. J Pharm Biomed Anal 2006; 41:1135-45. [PMID: 16554136 DOI: 10.1016/j.jpba.2006.02.020] [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] [Received: 12/08/2005] [Revised: 02/08/2006] [Accepted: 02/08/2006] [Indexed: 10/24/2022]
Abstract
A liquid chromatographic-mass spectrometric method with electrospray ionization is presented for the simultaneous determination of buprenorphine, nordiazepam and their pharmacologically active metabolites, norbuprenorphine and oxazepam, in rat plasma. The drugs were extracted from plasma by liquid-liquid extraction and chromatographically separated using a gradient elution of aqueous ammonium formate and acetonitrile. Following electrospray ionization, the analytes were quantified in the single ion storage mode. The assay was validated according to current acceptance criteria for bioanalytical method validation. It was proved to be linear from 0.7 to 200 ng/ml plasma for buprenorphine, 1.0 to 200 ng/ml for norbuprenorphine, 2.0 to 200 ng/ml for nordiazepam, and from 5.0 to 200 ng/ml for oxazepam. The average recoveries of buprenorphine, norbuprenorphine, nordiazepam and oxazepam were 89, 39, 88 and 82%, respectively, with average coefficients of variation ranging from 1.8 to 14.3%. The limits of quantitation for these drugs were 0.7, 1.0, 2.0 and 5.0 ng/ml, respectively, with associated precisions within 17% and accuracies within +/-18% of the nominal values. Both the intra- and inter-assay precision values did not exceed 11.3% for the four analytes. Intra- and inter-assay accuracies lay within +/-15% of the nominal values. The validated method was applied to the determination of buprenorphine, norbuprenorphine, nordiazepam and oxazepam in plasma samples collected from rats at various times after intravenous administration of buprenorphine and nordiazepam.
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Affiliation(s)
- Stephane Pirnay
- Laboratoire de Toxicologie de la Préfecture de Police, 2 Place Mazas, F-75012 Paris, France.
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14
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Fang T, Wang Y, Ma Y, Su W, Bai Y, Zhao P. A rapid LC/MS/MS quantitation assay for naringin and its two metabolites in rats plasma. J Pharm Biomed Anal 2006; 40:454-9. [PMID: 16406442 DOI: 10.1016/j.jpba.2005.07.031] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2005] [Revised: 07/16/2005] [Accepted: 07/19/2005] [Indexed: 11/17/2022]
Abstract
Naringin is a flavonoid that exists in many plants and traditional Chinese medicines. In this study, a highly sensitive and specific electrospray ionization (ESI) liquid chromatography-tandem mass spectrometry (LC/MS/MS) method was developed for quantification of naringin and its two metabolites, naringenin and naringenin glucuronide. Naringin and naringenin were extracted from rat plasma with ethyl acetate, using hesperidin as an internal standard. Components in the extract were separated on a 100 mm x 2.0 mm Betabasic 5 microm C18 ODS column by isocratic elution with 70% methanol. The components were analyzed in the multiple-reaction-monitoring (MRM) mode in the precursor/product ion pair of m/z 581.3/273.4 for naringin, m/z 273.4/153.1 for naringenin and m/z 611.5/303.4 for hesperidin, respectively. Linear calibration curves were obtained in the range of 5-1000 ng/ml, using 0.1 ml rat plasma. The within-day coefficients of variation (CVs) were 3.1, 1.8 and 2.2% for naringin, 3.0, 3.3, 3.1% for naringenin at 5, 50 and 500 ng/ml (n=5). The between-day CVs were 3.4, 1.7 and 4.9% for naringin and 4.0, 3.0, 4.6% for naringenin (n=5) at 5, 50 and 500 ng/ml respectively. A formulation based on PEG400 was used and orally administered to Sprague-Dawley male rats. Plasma drug concentrations were measured by this method and the pharmacokinetics was analyzed by WinNonlin computer software. Plasma concentration-time profiles of naringin were found to increase quickly and decline rapidly within 2 h and could not be detected after 24 h. Naringenin and naringenin glucuronide occurred slower and the T(max) were about 9 and 7.5 h later, respectively.
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Affiliation(s)
- Tiezheng Fang
- School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
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Liawruangrath S, Makchit J, Liawruangrath B. A Simple Flow Injection Spectrophotometric Procedure for the Determination of Diazepam in Pharmaceutical Formulation. ANAL SCI 2006; 22:127-30. [PMID: 16429787 DOI: 10.2116/analsci.22.127] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A single-channel flow injection (FI) manifold with spectrophotometric detection has been designed and fabricated for diazepam determination. A 100 microl sample and/or standard solution containing diazepam was injected into a flowing stream of 0.1 mol L(-1) hydrochloric acid with the optimum flow rate of 6.8 mL min(-1). As soon as the sample reached the detector, the FI signal as a peak was recorded at 360 nm. The optimum conditions for microg amounts of diazepam were achieved. A linear calibration graph over the range of 2-110 mg L(-1) diazepam was obtained with the regression equation Y = 0.2926X + 0.5896 (r2 = 0.9929). The method was very sensitive, since as little as 0.60 mg L(-1) could be detected; very reproducible with an RSD of 3.3% (n=11); and very rapid with a sampling rate of 100 h(-1). The limit of quantitation (10 sigma) was 2.0 mg L(-1). The proposed FI procedure has been satisfactorily applied to the quantitation of diazepam in commercial pharmaceutical formulations. The obtained results were in excellent agreement with those obtained by the conventional spectrophotometric method, verified by the student t-test at the 95% confidence level.
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Affiliation(s)
- S Liawruangrath
- Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand.
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Gonçalves JCS, Monteiro TM, Neves CSDM, Gram KRDS, Volpato NM, Silva VA, Caminha R, Gonçalves MDRB, Santos FMD, Silveira GED, Noël F. On-Line Solid-Phase Extraction Coupled With High-Performance Liquid Chromatography and Tandem Mass Spectrometry (SPE-HPLC-MS-MS) for Quantification of Bromazepam in Human Plasma. Ther Drug Monit 2005; 27:601-7. [PMID: 16175133 DOI: 10.1097/01.ftd.0000170027.28949.da] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A validated method for on-line solid-phase extraction coupled with high-performance liquid chromatography tandem mass spectrometry (SPE-HPLC-MS-MS) is described for the quantification of bromazepam in human plasma. The method involves a dilution of 300 muL of plasma with 100 muL of carbamazepine (2.5 ng/mL), used as internal standard, vortex-mixing, centrifugation, and injection of 100 muL of the supernate. The analytes were ionized using positive electrospray mass spectrometry then detected by multiple reaction monitoring (MRM). The m/z transitions 316-->182 (bromazepam) and 237-->194 (carbamazepine) were used for quantification. The calibration curve was linear from 1 ng/mL (limit of quantification) to 200 ng/mL. The retention times of bromazepam and carbamazepine were 2.6 and 3.2 minutes, respectively. The intraday and interday precisions were 3.43%-15.45% and 5.2%-17%, respectively. The intraday and interday accuracy was 94.00%-103.94%. This new automated method has been successfully applied in a bioequivalence study of 2 tablet formulations of 6 mg bromazepam: Lexotan(R) from Produtos Roche Químicos e Farmacêuticos SA, Rio de Janeiro, Brazil (reference) and test formulation from Laboratórios Biosintética Ltda, São Paulo, Brazil. Because the 90% CI of geometric mean ratios between reference and test were completely included in the 80%-125% interval, the 2 formulations were considered bioequivalent. The comparison of different experimental conditions for establishing a dissolution profile in vitro along with our bioavailability data further allowed us to propose rationally based experimental conditions for a dissolution test of bromazepam tablets, actually lacking a pharmacopeial monograph.
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Nyberg SL, Hardin J, Amiot B, Argikar UA, Remmel RP, Rinaldo P. Rapid, large-scale formation of porcine hepatocyte spheroids in a novel spheroid reservoir bioartificial liver. Liver Transpl 2005; 11:901-10. [PMID: 16035089 DOI: 10.1002/lt.20446] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We have developed a novel bioreactor based on the observation that isolated porcine hepatocytes rapidly and spontaneously aggregate into spheroids under oscillation conditions. The purpose of this study was to characterize the influence of oscillation frequency (0.125 Hz, 0.25 Hz), cell density (1-10 x 10(6) cells/mL), and storage condition (fresh, cryopreserved) of porcine hepatocytes on the kinetics of spheroid formation. The viability and metabolic performance of spheroid hepatocytes was also compared to monolayer culture. We observed that both fresh and cryopreserved porcine hepatocytes began formation of spheroids spontaneously at the onset of oscillation culture. Spheroid size was directly related to cell density and time in culture, though inversely related to oscillatory frequency. Spheroid formation by fresh porcine hepatocytes was associated with decreased cell death (lactate dehydrogenase release, 1.3 +/- 1.0 vs. 3.1 +/- 0.7 U/mL, P < 0.05) and increased metabolic performance (albumin production, 14.7 +/- 3.3 vs. 4.6 +/- 1.4 fg/c/h, P < 0.0001; ureagenesis from ammonia, 267 +/- 63 vs. 92 +/- 13 micromol/L/h, P < 0.001) compared with monolayer culture. In conclusion, based on the favorable properties of rapid spheroid formation, increased hepatocellular function, and ease of scale-up, the spheroid reservoir bioreactor warrants further investigation as a bioartificial liver for support of liver failure.
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Affiliation(s)
- Scott L Nyberg
- Department of Surgery, Mayo Clinic, Rochester, MN 55905, USA.
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Zayed MA, Fahmey MA, Hawash MF. Investigation of diazepam drug using thermal analyses, mass spectrometry and semi-empirical MO calculation. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2005; 61:799-805. [PMID: 15683781 DOI: 10.1016/j.saa.2004.06.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2004] [Accepted: 06/02/2004] [Indexed: 05/24/2023]
Abstract
In the present work diazepam (Dz) drug was investigated using thermal analyses (TA) measurements (TG/DTG) in comparison with EI mass spectral (MS) fragmentation at 70 and 20 eV. Semi-empirical MO calculations, MNDO procedure, have been carried out on diazepam both as neutral molecule and the corresponding positively charged molecular ion. These include molecular geometry, bond order, charge distribution, heats of formation and ionization energy. Thermogravimetric and kinetic analysis, reveal a high response of the drug to the temperature variation with very fast rate. It is completely decomposed in the temperature range between 204 and 340 degrees C with average kinetic energy (KE) at 164.69 kJ mol(-1). On the other hand, diazepam can easily fragmented at low energy after ionization by electron energy at 9.56 eV. The losses of CO gas molecules followed by chlorine gas from the entity of diazepam (both neutral and charged molecular ion) as the best selected pathway were observed in both mass spectra (MS) and thermal analyses (TA). MNDO calculation was applied to declare both TA and MS observations.
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Affiliation(s)
- M A Zayed
- Chemistry Department, Faculty of Science, Cairo University, Giza A.R.E., Egypt.
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van der Ven K, Van Dongen W, Maes BUW, Esmans EL, Blust R, De Coen WM. Determination of diazepam in aquatic samples by capillary liquid chromatography-electrospray tandem mass spectrometry. CHEMOSPHERE 2004; 57:967-973. [PMID: 15488587 DOI: 10.1016/j.chemosphere.2004.08.062] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2003] [Revised: 06/22/2004] [Accepted: 08/23/2004] [Indexed: 05/24/2023]
Abstract
In recent years growing attention has been paid toward the discharge, presence and potential adverse effects of pharmaceuticals in the environment. Using different existing analytical methods several studies have already identified a variety of drugs in waste-, surface- and drinking water. The monitoring of surface waters for drugs is of great importance because drugs are designed to be biological very active substances. A capillary LC/ES-MS-MS method has been developed that enables the sensitive and specific detection of diazepam in water samples up to 0.1 ng/ml (LOD). It requires neither multiple extraction steps, nor the use of large volumes of organic solvent. Applying this assay we have detected diazepam in 'in/effluent samples' collected in Belgium and demonstrated the applicability for water analysis without off-line pre-concentration of the analyte.
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Affiliation(s)
- Karlijn van der Ven
- Department of Biology, Laboratory of Ecophysiology, Biochemistry and Toxicology, University of Antwerp (RUCA), Groenenborgerlaan 171, B-2020 Antwerp, Belgium.
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Guo W, Lin H, Liu L, Song J. Polarographic determination of diazepam with its parallel catalytic wave in the presence of persulfate. J Pharm Biomed Anal 2004; 34:1137-44. [PMID: 15019049 DOI: 10.1016/j.jpba.2003.12.006] [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] [Received: 07/23/2003] [Revised: 12/05/2003] [Accepted: 12/09/2003] [Indexed: 10/26/2022]
Abstract
A new method for the determination of diazepam was proposed based on its polarographic catalytic wave in the presence of persulfate. In 0.20 M NaAc-HAc (pH 4.7)-1.0 x 10(-2) M K(2)S(2)O(8) supporting electrolyte, the reduction wave of diazepam with peak potential -0.89 V (versus SCE) was catalyzed, producing a parallel catalytic wave. The peak current of the catalytic wave was 15 times higher than that of the corresponding reduction wave for 4.0 x 10(-6) M diazepam, and was rectilinear to diazepam concentration in the range of 5.6 x 10(-8) to 8.9 x 10(-6) and 8.8 x 10(-6) to 2.0 x 10(-4) M. The detection limit was 9.6 x 10(-9) M. The mechanism of the parallel catalytic wave of diazepam was discussed.
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Affiliation(s)
- Wei Guo
- Department of Chemistry, Northwest University, Xi'an 710069, China
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Matsushita T, Amiot B, Hardin J, Platt JL, Nyberg SL. Membrane pore size impacts performance of a xenogeneic bioartificial liver1. Transplantation 2003; 76:1299-305. [PMID: 14627907 DOI: 10.1097/01.tp.0000080067.79190.3c] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
BACKGROUND We have developed a novel bioartificial liver (BAL) composed of porcine hepatocyte spheroids in a reservoir design. A semipermeable membrane is used to protect the spheroids from immune-mediated damage. This study was designed to assess the influence of membrane pore size on performance of the spheroid reservoir BAL. METHODS Eight healthy dogs were studied during primary and secondary exposures to the spheroid reservoir BAL using membranes with small (10 nm) or large (200 nm) pores. BAL performance was assessed by multiple functional assays. Spheroids were examined microscopically before and after all BAL treatments. Titers of xenoreactive antibody were monitored until elective death of animals on day 42. RESULTS Viability and functional performance of spheroids were significantly greater after all BAL treatments that used membranes with 10-nm versus 200-nm pores. Reduced performance in the 200 nm group was associated with 7.7-fold and 78.0-fold rise in xenoreactive antibody titers after first and second treatments, respectively. Dogs in the 10 nm group remained hemodynamically stable during all BAL treatments, whereas those in the 200 nm group experienced acute hypotension (P<0.001) during second BAL exposures. Microscopic examination of spheroids after BAL treatments indicated that deposition of canine proteins, including complement, was associated with reductions in both viability and functional performance of the BAL. CONCLUSIONS The elicited immune response of healthy dogs to a xenogeneic BAL was blocked and BAL performance significantly improved by reducing the permeability of the BAL membrane.
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Affiliation(s)
- Takakazu Matsushita
- Division of Solid Organ Transplantation, Division of Biochemistry and Molecular Biology, Transplantation Biology Program, Mayo Clinic, Rochester, MN, USA
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Potentiometric determination of diazepam, bromazepam and clonazepam using solid contact ion-selective electrodes. Anal Chim Acta 2003. [DOI: 10.1016/j.aca.2003.08.070] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Chapter 5 Automation tools and strategies for bioanalysis. ACTA ACUST UNITED AC 2003. [DOI: 10.1016/s1464-3456(03)80007-8] [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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Current literature in mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2002; 37:119-132. [PMID: 11813320 DOI: 10.1002/jms.248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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