Publications by authors named "Rosa Maria Jiménez"

8 Publications

  • Page 1 of 1

LC-MS/MS method for the determination of several drugs used in combined cardiovascular therapy in human plasma.

J Chromatogr B Analyt Technol Biomed Life Sci 2010 Oct 6;878(28):2685-92. Epub 2010 Aug 6.

Analytical Chemistry Department, Science and Technology Faculty, Basque Country University/EHU, P.O. Box 644, 48080 Bilbao, Basque Country, Spain.

A simple, fast and validated method is reported for the simultaneous analysis, in human plasma, of several drugs usually combined in cardiovascular therapy (atenolol, bisoprolol, hydrochlorothiazide, chlorthalidone, salicylic acid, enalapril and its active metabolite enalaprilat, valsartan and fluvastatin) using high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) with electrospray ionization (ESI), working in multiple reaction monitoring mode (MRM). Separation of analytes and internal standard (pravastatin) was performed on a Luna C18(2) (150mm×4.6mm, 3μm) column using a gradient elution mode with a run time of 15min. The mobile phase consisted of a mixture of acetonitrile and water containing 0.01% formic acid and 10mM ammonium formate at pH 4.1. Sample treatment consisted of a simple protein precipitation with acetonitrile, enabling a fast analysis. The method showed good linearity, precision (RSD% values between 0.7% and 12.7%) and accuracy (relative error values between 0.9% and 14.0%). Recoveries were within 68-106% range and the ion-suppression was not higher than 22% for any analyte. The method was successfully applied to plasma samples obtained from patients under combined cardiovascular treatment.
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http://dx.doi.org/10.1016/j.jchromb.2010.07.026DOI Listing
October 2010

Validation of a fast liquid chromatography-UV method for the analysis of drugs used in combined cardiovascular therapy in human plasma.

J Chromatogr B Analyt Technol Biomed Life Sci 2009 Oct 19;877(27):3045-53. Epub 2009 Jul 19.

Pintura Saila, Arte Ederretako Fakultatea, Euskal Herriko Unibertsitatea/UPV, P.K. 644, 48080 Bilbo, Basque Country, Spain.

Ultra-performance liquid chromatography (UPLC) was investigated as a faster alternative to high-performance liquid chromatography (HPLC) for the simultaneous analysis of drugs usually prescribed in cardiovascular therapy. Upon a previously developed and validated solid phase extraction (SPE)-HPLC-photodiode array (PDA)-fluorescence (FLR) method, separation of chlorthalidone (CLTD; diuretic), valsartan and its metabolite (VAL and VAL-M1 respectively; angiotensin II receptor antagonist drugs) and fluvastatin (FLUV; statin) was performed in human plasma using an RP C18 column (50mmx2.1mm, 1.7microm, Waters Acquity UPLC (BEH)) and a tunable UV-vis (TUV) detector. After method transfer, different system variables were modulated to study the evolution of responses of the analytes and the endogenous interferences. The improved method was fully validated and the results were compared with its precursor HPLC method relating to analysis time, efficiency and sensitivity. The studied compounds were separated in less than 8min and the method showed good linearity (20-3000microg/L for chlorthalidone, 110-1100microg/L for valsartan-M1, 67-1900microg/L for valsartan and 48-1100microg/L for fluvastatin), precision and accuracy. The proposed method was found to be reproducible (RSD<10%), accurate (RE<15%), robust and suitable for quantitative analysis of the studied drugs in plasma obtained from patients under combined cardiovascular treatment.
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http://dx.doi.org/10.1016/j.jchromb.2009.07.018DOI Listing
October 2009

Optimization and validation of a SPE-HPLC-PDA-fluorescence method for the simultaneous determination of drugs used in combined cardiovascular therapy in human plasma.

J Pharm Biomed Anal 2009 Nov 5;50(4):630-9. Epub 2008 Nov 5.

Kimika Analitikoa Saila, Zientzia eta Teknologia Fakultatea, Euskal Herriko Unibertsitatea/UPV, P.K. 644, 48080 Bilbo, Basque Country, Spain.

This paper reports the chemometrical optimization and the validation of a quantitative high performance liquid chromatography-photodiode array-fluorescence (HPLC-PDA-Fluo) method for the simultaneous analysis, in human plasma, of drugs usually combined in cardiovascular therapy. Separation of chlorthalidone (CLTD), valsartan (VAL), valsartan-M1 (VAL-M1), fluvastatin (FLUV) and the internal standard (IS) candesartan cilexetil was performed on a dC18 Atlantis column (100 mm x 3.9 mm, 3 microm) using a gradient with a run time of 15 min. The mobile phase consisted of a mixture of acetonitrile and water containing 0.01% of formic acid and 10 mM of ammonium formate at pH 4.1. UV and fluorimetric (valsartan, its metabolite and fluvastatin) detectors were used. The sample preparation consisted of protein precipitation using acetonitrile suited to a solid-phase extraction (SPE) on a Strata-X cartridge for sample clean-up. Method validation was developed following the recommendations for bioanalytical method validation of International Conference on Harmonisation (ICH) and Food and Drug Administration (FDA) organizations. The method showed good linearity (31-3000 microg/l for chlorthalidone, 20-1000 microg/l for valsartan-M1, 10-5000 microg/l for valsartan and 14-1000 microg/l for fluvastatin), precision and accuracy. Recoveries were in the range of 78-91%. This method allowed the determination of these drugs in human plasma samples obtained from patients under cardiovascular treatment.
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http://dx.doi.org/10.1016/j.jpba.2008.10.037DOI Listing
November 2009

Separation and quantitation of several angiotensin II receptor antagonist drugs in human urine by a SPE-HPLC-DAD method.

J Sep Sci 2008 Mar;31(4):667-76

Departamento de Química Analítica, Facultad de Ciencia y Tecnología, Leioa, Spain.

In this work, an SPE-HPLC method coupled to photodiode array detection was validated in human urine matrix, in order to monitor four antihypertensive angiotensin II receptor antagonist drugs in patients under cardiovascular treatment. For that purpose, experimental design was used. Quantitation was accomplished by the internal standard method. The obtained LOQs were 95, 113, 125, and 85 ng/mL for eprosartan, telmisartan, irbesartan, and valsartan, respectively. The intraday and interday precision and accuracy at four concentration levels in the working range (LOQ-15 microg/mL) were always lower than 11% RSD and 8% relative error. The urine samples proved to be stable during 4 h at room temperature, after three thaw-freeze cycles, and for 2 months at -20 degrees C. No interferences from other endogenous compounds or co-administered drugs were found. The method has been successfully applied to monitor the renal elimination of eprosartan and valsartan during 24 h.
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http://dx.doi.org/10.1002/jssc.200700442DOI Listing
March 2008

Biovalidation of an SPE-HPLC-UV-fluorescence method for the determination of valsartan and its metabolite valeryl-4-hydroxy-valsartan in human plasma.

J Sep Sci 2007 Sep;30(14):2231-40

Kimika Analitikoaren Saila, Zientzia eta Teknologia Fakultatea, Euskal Herriko Unibertsitatea/UPV, Bilbo, Basque Country, Spain.

A simple and fast method for the simultaneous determination of the antihypertensive drug Valsartan and its metabolite in human plasma has been validated. The proposed method deals with SPE, followed by an HPLC separation coupled with fluorimetric and photometric detection. The optimization of the SPE-HPLC method was achieved by an experimental design. The separation was performed on an RP C18 Atlantis 100 mmx3.9 mm column. The mobile phase consisted of a mixture of ACN 0.025% TFA and phosphate buffer (5 mM, pH = 2.5) 0.025% TFA and was delivered in gradient mode at a flow rate of 1.30 mL/min. The eluent was monitored with a fluorescence detector at 234 and 378 nm excitation and emission wavelengths, respectively, and at 254 nm using a photometric detector. The full analytical validation was performed according to the Food and Drug Administration (FDA) 'guidance for industry: bioanalytical method validation' and the recoveries obtained for Valsartan and its metabolite ranged from 94.6 to 108.8%. The validated method was successfully applied to 12 plasma samples obtained from patients under antihypertensive treatment with Valsartan.
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http://dx.doi.org/10.1002/jssc.200700033DOI Listing
September 2007

Optimization via experimental design of an SPE-HPLC-UV-fluorescence method for the determination of valsartan and its metabolite in human plasma samples.

J Sep Sci 2006 Oct;29(15):2265-83

Kimika Analitikoaren Saila, Zientzia eta Teknologia Fakultatea, Euskal Herriko Unibertsitatea/UPV, Bilbo, Basque Country, Spain.

A chemometric approach was applied for the optimization of the extraction and separation of the antihypertensive drug valsartan and its metabolite valeryl-4-hydroxy-valsartan from human plasma samples. Due to the high number of experimental and response variables to be studied, fractional factorial design (FFD) and central composite design (CCD) were used to optimize the HPLC-UV-fluorescence method. First, the significant variables were chosen with the help of FFD; then, a CCD was run to obtain the optimal values for the significant variables. The measured responses were the corrected areas of the two analytes and the resolution between the chromatographic peaks. Separation of valsartan, its metabolite valeryl-4-hydroxy-valsartan and candesartan M1, used as internal standard, was made using an Atlantis dC18 100 mm x 3.9 mm id, 100 angstroms, 3 microm chromatographic column. The mobile phase was run in gradient elution mode and consisted of ACN with 0.025% TFA and a 5 mM phosphate buffer with 0.025% TFA at pH 2.5. The initial percentage of ACN was 32% with a stepness of 4.5%/min to reach the 50%. A flow rate of 1.30 mL/min was applied throughout the chromatographic run, and the column temperature was kept to 40+/-0.2 degrees C. In the SPE procedure, experimental design was also used in order at achieve a maximum recovery percentage and extracts free from plasma interferences. The extraction procedure for spiked human plasma samples was carried out using C8 cartridges, phosphate buffer (pH 2, 60 mM) as conditioning agent, a washing step with methanol-phosphate buffer (40:60 v/v), a drying step of 8 min, and diethyl ether as eluent. The SPE-HPLC-UV-fluorescence method developed allowed the separation and quantitation of valsartan and its metabolite from human plasma samples with an adequate resolution and a total analysis time of 1 h.
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http://dx.doi.org/10.1002/jssc.200600093DOI Listing
October 2006

Multivariate optimisation of a cyclodextrin-assisted-capillary zone electrophoretic method for the separation of torasemide and its metabolites.

J Chromatogr A 2003 Mar;990(1-2):271-9

Departamento de Química Analítica, Facultad de Ciencias, Universidad del País Vasco, Apdo. 644, 48080 Bilbao, Spain.

In this work, a rapid cyclodextrin-assisted capillary electrophoretic method is developed for the separation of the diuretic torasemide and three of its metabolites. Both fractional factorial and central composite designs were employed to optimise the separation method. The factors studied were pH, concentration of methyl-beta-cyclodextrin, concentration of the background electrolyte and percentage of acetonitrile as organic modifier. Monitored response was a composite quality response (Q*) which balanced conflicting normalized responses, such as resolution and migration time. Optimal separation of the four studied compounds was achieved in less than 6.5 min, using an electrolyte of 60 mM borate buffer with no organic modifier and 25 mM methyl-beta-cyclodextrin concentration adjusted to pH 8.0 at a potential of 30 kV. Detection wavelength and temperature were 197 nm and 20 degrees C respectively. This work means a significant improvement with regard to a previous separation method for these compounds developed in our laboratory.
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http://dx.doi.org/10.1016/s0021-9673(03)00055-4DOI Listing
March 2003

Determination of the angiotensin-converting enzyme inhibitor quinapril and its metabolite quinaprilat in pharmaceuticals and urine by capillary zone electrophoresis and solid-phase extraction.

Electrophoresis 2002 Jan;23(1):102-9

Departamento de Química Analítica, Facultad de Ciencias, Universidad del País, Vasco UPV/EHU, Bilbao, Spain.

Quinapril is an antihypertensive drug commonly used in the treatment of hypertension and congestive heart failure. In this work, a capillary zone electrophoresis system is optimized for the analysis of quinapril and its active metabolite quinaprilat in urine, as well as for the determination of the drug and its combination with hydrochlorothiazide in pharmaceuticals. The separation takes place in a fused-silica capillary. The running electrolyte consists of a 60 mM borate buffer solution, pH 9.5. The analysis of urine samples requires a previous extraction step using C8 solid-phase cartridges. Under the optimum experimental conditions, the separation of the two analytes and the internal standard takes less than 5 min. The detection limits obtained (75 and 95 ng/mL for quinapril and quinaprilat, respectively) allow the application of the electrophoretic method to the determination of the drug and its metabolite in urine samples obtained from four patients treated with quinapril.
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http://dx.doi.org/10.1002/1522-2683(200201)23:1<102::AID-ELPS102>3.0.CO;2-CDOI Listing
January 2002