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  • 1.
    Abdel-Rehim, Mohamed
    Karlstads universitet, Fakulteten för teknik- och naturvetenskap, Avdelningen för kemi och biomedicinsk vetenskap. AstraZeneca R&D Sodertalje, Global DMPK, SE-15185 Sodertalje, Sweden.;Stockholm Univ, Dept Analyt Chem, SE-10691 Stockholm, Sweden.;Karlstad Univ, Dept Chem & Biomed Sci, Fac Sci & Technol, SE-65188 Karlstad, Sweden..
    Microextraction by packed sorbent (MEPS): A tutorial2011Inngår i: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 701, nr 2, s. 119-128Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This tutorial provides an overview on a new technique for sample preparation, microextraction by packed sorbent (MEPS). Not only the automation process by MEPS is the advantage but also the much smaller volumes of the samples, solvents and dead volumes in the system. Other significant advantages such as the speed and the simplicity of the sample preparation process are provided. In this tutorial the main concepts of MEPS will be elucidated. Different practical aspects in MEPS are addressed. The factors affecting MEPS performance will be discussed. The application of MEPS in clinical and pre-clinical studies for quantification of drugs and metabolites in blood, plasma and urine will be provided. A comparison between MEPS and other extraction techniques such as SPE, LLE, SPME and SBSE will be discussed. (C) 2011 Elsevier B.V. All rights reserved.

  • 2.
    Abdel-Rehim, Mohamed
    Karlstads universitet, Fakulteten för teknik- och naturvetenskap, Avdelningen för kemi och biomedicinsk vetenskap. AstraZeneca R&D Sodertalje, Global DMPK, Sodertalje, Sweden.;Karlstad Univ, Fac Sci & Technol, Dept Chem & Biomed Sci, Karlstad, Sweden..
    On-Line Whole Blood Analysis Using Microextraction by Packed Sorbent and LC-MS-MS2011Inngår i: LC GC North America, ISSN 1527-5949, E-ISSN 1939-1889, Vol. 29, nr 7, s. 612-618Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Microextraction by packed sorbent (MEPS) is a new technique for sample preparation that can be connected on-line with liquid chromatography (LC) or gas chromatography (GC) systems without any modifications. This article describes the use of MEPS in clinical and preclinical studies to quantify different drugs in whole blood samples. MEPS was used to determine cyclophosphamide in mouse blood from preclinical g studies using 20 mu L of blood samples. The interday accuracies and 0 precisions ranged from 107-109% and from 2.0-7.0%, respectively. The determination of four immunosuppressive drugs in human blood by MEPS and liquid chromatography-mass spectrometry (LC-MS) is described. The method showed a good selectivity and sensitivity. The calibration curves for everolimus, sirolimus, and tacrolimus ranged from 0.5 to 50 ng/mL and for cyclosporine from 3.0 to 1500 ng/mL. Intraday precisions for the studied immunosuppressive drugs were 2.0-11.7% and interday precision ranged from 5.1 to 13.7% (CV).

  • 3.
    Aboul-Enein, Mohamed N.
    et al.
    Natl Res Ctr, Pharmaceut & Drug Ind Res Div, Med & Pharmaceut Chem Dept, Med Chem Grp, Giza 12622, Egypt..
    El-Azzouny, Aida A.
    Natl Res Ctr, Pharmaceut & Drug Ind Res Div, Med & Pharmaceut Chem Dept, Med Chem Grp, Giza 12622, Egypt..
    Attia, Mohamed I.
    Natl Res Ctr, Pharmaceut & Drug Ind Res Div, Med & Pharmaceut Chem Dept, Med Chem Grp, Giza 12622, Egypt.;King Saud Univ, Coll Pharm, Dept Pharmaceut Chem, Riyadh 11451, Saudi Arabia..
    Maklad, Yousreya A.
    Natl Res Ctr, Pharmaceut & Drug Ind Res Div, Med & Pharmaceut Chem Dept, Pharmacol Grp, Giza 12622, Egypt..
    Amin, Kamilia M.
    Cairo Univ, Fac Pharm, Dept Pharmaceut Chem, Cairo, Egypt..
    Abdel-Rehim, Mohamed
    Karlstad Univ, Dept Chem, SE-65188 Karlstad, Sweden..
    El-Behairy, Mohammed F.
    Natl Res Ctr, Pharmaceut & Drug Ind Res Div, Med & Pharmaceut Chem Dept, Med Chem Grp, Giza 12622, Egypt..
    Design and synthesis of novel stiripentol analogues as potential anticonvulsants2012Inngår i: European Journal of Medicinal Chemistry, ISSN 0223-5234, E-ISSN 1768-3254, Vol. 47, s. 360-369Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A series of stiripentol (SIP) analogues namely, 2-1(1E)-1-(1,3-benzodioxol-5-yl)-4,4-dimethylpent-1-en-3-ylidene]-N-(aryl/H)hydrazinecarboxamides 7a-h, (+/-)-(5RS)-N-(aryl/H)-(1,3-benzodioxol-5-yl)-3-tert-butyl-4,5-dihydro-1H-pyrazole-1-carboxamides (+/-)-8a-h, and (+/-)-[(5RS)-(1,3-benzodioxol-5-yl)-3-tert-butyl-4,5-dihydro-1H-pyrazol-1-yl](aryl)methanones (+/-)-13a-f was synthesized by adopting appropriate synthetic routes and was pharmacologically evaluated in the preliminary anticonvulsant screens. The selected bioactive new chemical entities were subjected to ED50 determination and neurotoxicity evaluation. The most active congeners are 7h in MES screen and (+/-)-13b in scPTZ screen which displayed ED50 values of 87 and 110 mg/kg, respectively, as compared to that of STP (ED50 = 277.7 and 115 mg/kg in MES and scPTZ, respectively). (C) 2011 Elsevier Masson SAS. All rights reserved.

  • 4.
    Ashri, Nadia Y.
    et al.
    Najd Consulting Hosp, Riyadh, Saudi Arabia..
    Abdel-Rehim, Mohamed
    Karlstads universitet, Fakulteten för teknik- och naturvetenskap, Avdelningen för kemi och biomedicinsk vetenskap. AstraZeneca R&D Sodertalje, Clin Pharmacol, SE-15185 Sodertalje, Sweden.;AstraZeneca R&D Sodertalje, DMPK, SE-15185 Sodertalje, Sweden.;Karlstad Univ, Dept Chem & Biomed Sci, SE-65188 Karlstad, Sweden.;Stockholm Univ, Dept Analyt Chem, SE-10691 Stockholm, Sweden..
    Sample treatment based on extraction techniques in biological matrices2011Inngår i: Bioanalysis, ISSN 1757-6180, E-ISSN 1757-6199, Vol. 3, nr 17, s. 2003-2018Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    The importance of sample preparation methods as the first stage in bioanalysis is described. In this article, the sample preparation concept and strategies will be discussed, along with the requirements for good sample preparation. The most widely used sample preparation methods in the pharmaceutical industry are presented; for example, the need for same-day rotation of results from large numbers of biological samples in pharmaceutical industry makes high throughput bioanalysis more essential. In this article, high-throughput sample preparation techniques are presented; examples are given of the extraction and concentration of analytes from biological matrices, including protein precipitation, solid-phase extraction, liquid-liquid extraction and microextraction-related techniques. Finally, the potential role of selective extraction methods, including molecular imprinted phases, is considered.

  • 5.
    Hegazy, Mohamed-Elamir F.
    et al.
    Natl Res Ctr, Pharmaceut Res Lab, Ctr Excellence Adv Sci, Cairo 12622, Egypt.;Natl Res Ctr, Chem Med Plants Dept, Giza 12622, Egypt..
    El-Beih, Ahmed A.
    Natl Res Ctr, Pharmaceut Res Lab, Ctr Excellence Adv Sci, Cairo 12622, Egypt.;Natl Res Ctr, Chem Nat & Microbial Prod Dept, Giza 12622, Egypt..
    Moustafa, Alaa Y.
    Sohag Univ, Dept Zool, Fac Sci, Sohag, Egypt..
    Hamdy, Abdelhamed A.
    Natl Res Ctr, Chem Nat & Microbial Prod Dept, Giza 12622, Egypt..
    Alhammady, Montaser A.
    Natl Inst Oceanog & Fisheries, Red Sea Branch, Hurghada, Egypt..
    Selim, Rehab M.
    Natl Res Ctr, Chem Nat & Microbial Prod Dept, Giza 12622, Egypt..
    Abdel-Rehim, Mohamed
    Karlstads universitet, Fakulteten för teknik- och naturvetenskap, Avdelningen för kemi och biomedicinsk vetenskap. Natl Res Ctr, Pharmaceut Res Lab, Ctr Excellence Adv Sci, Cairo 12622, Egypt.;Karlstad Univ, Dept Chem & Biomed Sci, Fac Sci & Technol, SE-65188 Karlstad, Sweden.;Astra Zeneca, R&D, Dept Clin Pharmacol, S-15185 Sodertalje, Sweden.;Astra Zeneca, R&D, DMPK, S-15185 Sodertalje, Sweden..
    Pare, Paul W.
    Texas Tech Univ, Dept Chem & Biochem, Lubbock, TX 79409 USA..
    Cytotoxic Cembranoids from the Red Sea Soft Coral Sarcophyton glaucum2011Inngår i: Natural Product Communications, ISSN 1934-578X, E-ISSN 1555-9475, Vol. 6, nr 12, s. 1809-1812Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    One new cembrane diterpene, 2R,7R,8R-dihydroxydeepoxysarcophine (1), together with three known compounds, 7 alpha,8 beta-dihydroxydecpoxysarcophine (2), 7 beta-acetoxy-8 alpha-hydroxydeepoxysarcophine (3), and sarcophine (4), have been isolated from the Red Sea soft coral Sarcophyton glaucum. Their structures were determined using 1D and 2D NMR spectroscopy. 7 beta-Acetoxy-8 alpha-hydroxydeepoxysarcophine (3) exhibits cytotoxic activity against HepG2, HCT-116, and HeLa cells with IC(50) values of 3.6, 2.3, and 6.7 mu g/mL, respectively.

  • 6.
    Moein, Mohammad Mahdi
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för analytisk kemi.
    El-Beqqali, Aziza
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för analytisk kemi.
    Abdel-Rehim, Abbi
    Jeppsson-Dadoun, Amin
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för analytisk kemi.
    Abdel-Rehim, Mohamed
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för analytisk kemi.
    Preparation of monolithic molecularly imprinted polymer sol-gel packed tips for high-throughput bioanalysis: Extraction and quantification of L-tyrosine in human plasma and urine samples utilizing liquid chromatography and tandem mass spectrometry2014Inngår i: Journal of chromatography. B, ISSN 1570-0232, E-ISSN 1873-376X, Vol. 967, s. 168-173Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In situ monolithic molecularly imprinted polymer sol-gel packed tips (MMSTs) were prepared and evaluated for the extraction of lung cancer biomarker L-tyrosine (Tyr) from human plasma and urine samples. Several extraction parameters such as the conditioning, washing and elution solutions, pH and time were investigated. The enrichment factor (EF) and extraction recovery (ER) were studied. MMST showed good selectivity and a high extraction recovery, and MMST as a sorbent showed good stability and repeatability. The method validation showed good regression correlation coefficients for plasma and urine samples (R-2 >= 0.996) within the concentration range of 5-1000 and 1-1000 nmol L-1 in plasma and urine samples, respectively. The lower limits of quantification (LLOQ) in the plasma and urine samples were 5 and 1 nmol L-1, respectively. The between-batch precision for Tyr in plasma ranged from 1.0 to 6.0%, and in urine it was from 1.0 to 7.0%. The results show that the developed method has more facility, stability, durability and repeatability compared with previous similar methods. To the best of our knowledge, this is the first study aimed at the selective separation of Tyr as a lung cancer biomarker by MMSTs from biological matrixes and detection by LC/MS/MS.

  • 7.
    Said, Rana
    et al.
    Huddinge Univ Hosp, Dept Clin Pharmacol, S-17176 Stockholm, Sweden..
    Kamel, Mohamed
    Huddinge Univ Hosp, Dept Clin Pharmacol, S-17176 Stockholm, Sweden..
    El-Beqqali, Aziza
    Huddinge Univ Hosp, Dept Clin Pharmacol, S-17176 Stockholm, Sweden..
    Abdel-Rehim, Mohamed
    Karlstads universitet, Fakulteten för teknik- och naturvetenskap, Avdelningen för kemi och biomedicinsk vetenskap. Karlstad Univ, Dept Chem & Biomed Sci, Fac Sci & Technol, S-65188 Karlstad, Sweden.;AstraZeneca R&D, Dept Clin Pharmacol, S-15185 Sodertalje, Sweden.;AstraZeneca R&D, DMPK, S-15185 Sodertalje, Sweden..
    Microextraction by packed sorbent for LC-MS/MS determination of drugs in whole blood samples2010Inngår i: Bioanalysis, ISSN 1757-6180, E-ISSN 1757-6199, Vol. 2, nr 2, s. 197-205Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: Microextraction by packed sorbent (MEPS) is used as an online sample-preparation method. The determination of local anesthetics lidocaine, ropivacaine and bupivacaine directly in human blood was performed using MEPS online with LC-MS/MS. Results: The range of the calibration curves in whole blood was 10-10000 nmol/l. The lower limit of quantification was set to 10.0 nmol/l. The accuracy of the quality control samples ranged from 85 to 97%. The interday precision of the studied analytes was within the range 1-5%. The regression correlation coefficient (r(2)) was over 0.995 for all runs. The present method is rapid, reliable and robust and may be used for therapeutic drug monitoring of studied analytes in whole blood. Conclusion: This assay allows the analysis of drugs in human blood directly. Sample preparation is simple and automated. The assay reduced the handling time and the cost, and could handle small volumes of whole blood samples (25 mu l).

  • 8. Vlčková, Hana
    et al.
    El-Beqqali, Aziza
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för analytisk kemi.
    Nováková, Lucie
    Solich, Petr
    Abdel-Rehim, Mohamed
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för analytisk kemi.
    Determination of amphetamine and methadone in human urine by microextraction by packed sorbent coupled directly to mass spectrometry: An alternative for rapid clinical and forensic analysis2014Inngår i: Journal of Separation Science, ISSN 1615-9306, E-ISSN 1615-9314, Vol. 37, nr 22, s. 3306-3313Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Speed and low cost, together with regulatory approval, are the most important requirements of clinical assays. Therefore, a fast and automated on-line sample preparation method is essential for the routine analysis of biological samples. Microextraction by packed sorbent is an option for optimal sample preparation due to its easy automation, minimal requirements for the sample and elution solvent volumes, elimination of evaporation and reconstitution steps, and ability to integrate sample preparation and injection into one step. The use of effective sample preparation steps circumvents the need for chromatographic separation and therefore allows more rapid and less expensive sample analysis in clinical and forensic practice. Two biologically active compounds, amphetamine and methadone, were chosen as representative drugs of abuse for the application of microextraction by packed sorbent coupled directly to mass spectrometry. The developed method was validated, with the results confirming the suitability of the combination of these techniques for the analysis of biological samples. The approach was confirmed to be appropriate for use in clinical and forensic practice with regard to cost and time requirements for analysis.

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