Science Labormed Pharma SA

Bucharest, Romania

Science Labormed Pharma SA

Bucharest, Romania
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Petroviciu I.,National Museum of Romanian History | Petroviciu I.,University of Bucharest | Medvedovici A.,University of Bucharest | Albu F.,Science LaborMed Pharma S.A. | And 2 more authors.
Romanian Reports in Physics | Year: 2012

An analytical protocol for the identification of natural dyes in historic textiles by LC-MS and LC-MS/MS was recently developed for the first time in Romania. The present study discusses the application of this approach in the identification of dyes and biological sources in very low amounts of fibers from textiles in local collections.

Voicu V.,Carol Davila University of Medicine and Pharmacy | Voicu V.,Romanian Army Center for Medical Research | Albu F.,Science Labormed Pharma SA | Tache F.,University of Bucharest | And 4 more authors.
Bioanalysis | Year: 2013

Background: Extreme efforts are made for the structural diversification of oximes used as AChE reactivators. Co-administration of different oximes should also be considered as a solution in therapy. Consequently, development of selective assays of oximes in biological matrices is of major importance. Results: Three chromatographic separation mechanisms were evaluated: hydrophilic-interaction LC; mixed reversed-phase/cation exchange (DUET); and reversed-phase ion pairing based on per-fluorinated agents. MS was used to identify and quantify oximes. Alternative preparation of whole blood and plasma samples were used based on protein precipitation through addition of acetonitrile or ionic liquids. Quality characteristics of the proposed analytical approaches are discussed. Conclusion: The reversed-phase ion pairing based on per-fluorinated agents chromatographic separation mechanism and positive ESI-MS/MS detection produced the best results for the assay of bis-quaternary pyridinium oximes. LLOQ in the tenths of nanogram per milliliter range are achievable. © 2013 Future Science Ltd.

Petroviciu I.,National Research Institute for Conservation and Restoration INCCR | Albu F.,Science LaborMed Pharma S.A. | Medvedovici A.,University of Bucharest
Microchemical Journal | Year: 2010

Identification of dyes in historic textiles was until recently only based on reversed phase liquid chromatography and diode-array detection (RPLC-DAD). Although in the last years mass spectrometry (MS) is increasingly used as a detection system for liquid chromatography, most applications in the field are directed to identification of the molecular ions or in studies dedicated to degradation products which may be used as markers in RPLC-DAD. In the present work, an analytical protocol for the identification of dyes using RPLC/ESI/MS is presented. Atmospheric pressure electrospray ionization (ESI) was applied, in the negative ion monitoring mode. Both single stage and tandem MS (MS/MS) approaches were considered. An ion trap was used as mass analyzer. Experiments are based on the characterization of standards (natural dyes and/or dyed fibers) with the mass spectrometer sequentially working in the following modes: single MS/full scan, followed by plotting chromatograms through ion extraction (IEC) according to mass/charge ratios corresponding to molecular ions; single MS/selected ion monitoring (SIM) mode; tandem MS/single reaction monitoring (SRM) mode; tandem MS/multiple reactions monitoring (MRM) or product ion scanning modes. A faster chromatographic separation could be applied as MS detection readily balanced the selectivity of the analytical process. In a case study, 11 dyes from 3 biological sources were detected in a 0.5 mg historic sample. © 2009 Elsevier B.V. All rights reserved.

Medvedovici A.,University of Bucharest | Medvedovici A.,Science Labormed Pharma SA | Udrescu S.,Science Labormed Pharma SA | Albu F.,Science Labormed Pharma SA | And 2 more authors.
Bioanalysis | Year: 2011

Background: Liquid-liquid extraction of target compounds from biological matrices followed by the injection of a large volume from the organic layer into the chromatographic column operated under reversed-phase (RP) conditions would successfully combine the selectivity and the straightforward character of the procedure in order to enhance sensitivity, compared with the usual approach of involving solvent evaporation and residue re-dissolution. Large-volume injection of samples in diluents that are not miscible with the mobile phase was recently introduced in chromatographic practice. The risk of random errors produced during the manipulation of samples is also substantially reduced. Results: A bioanalytical method designed for the bioequivalence of fenspiride containing pharmaceutical formulations was based on a sample preparation procedure involving extraction of the target analyte and the internal standard (trimetazidine) from alkalinized plasma samples in 1-octanol. A volume of 75 μl from the octanol layer was directly injected on a Zorbax SB C18 Rapid Resolution, 50 mm length × 4.6 mm internal diameter × 1.8 μm particle size column, with the RP separation being carried out under gradient elution conditions. Detection was made through positive ESI and MS/MS. Aspects related to method development and validation are discussed. Conclusions: The bioanalytical method was successfully applied to assess bioequivalence of a modified release pharmaceutical formulation containing 80 mg fenspiride hydrochloride during two different studies carried out as single-dose administration under fasting and fed conditions (four arms), and multiple doses administration, respectively. The quality attributes assigned to the bioanalytical method, as resulting from its application to the bioequivalence studies, are highlighted and fully demonstrate that sample preparation based on large-volume injection of immiscible diluents has an increased potential for application in bioanalysis. © 2011 Future Science Ltd.

Sora D.I.,Science LaborMed Pharma S.A. | Udrescu T.,Science LaborMed Pharma S.A. | Albu F.,Science LaborMed Pharma S.A. | David V.,University of Bucharest | And 2 more authors.
Journal of Pharmaceutical and Biomedical Analysis | Year: 2010

A new sensitive HPLC/MS/MS method for simultaneous determination of furosemide, spironolactone and canrenone in human plasma samples is presented. Electrospray ionization source (ESI) has been used. The tandem MS detection was performed under MRM conditions, in the negative ion mode for furosemide and indapamide (internal standard 1) and in the positive ion mode for spironolactone, canrenone and nitrazepam (internal standard 2). A simple plasma protein precipitation with acetonitrile was used as sample preparation technique. The chromatographic separation was carried out under the reversed phase mechanism, on a 250. mm length column packed with octadecyl modified silicagel and thermostated at 35°C. The column was operated under isocratic conditions (3:7 aqueous 0.1% formic acid and methanol, v/v) at a flow rate of 0.8. mL/min. Quantitation intervals of 20-1600. ng/mL for furosemide and 2-100. ng/mL for spironolactone and canrenone have been concluded through validation. Precision and accuracy were situated within the accepted thresholds (maximum 15% relative standard deviation and ±15% percentage bias). The most sensitive aspects relating to the analytical method development and validation were highlighted and critically assessed in order to reach an objective opinion about the real performances and inherent applicability of the method in bioanalysis. © 2010 Elsevier B.V.

Medvedovici A.,University of Bucharest | Albu F.,Science LaborMed Pharma S.A. | David V.,University of Bucharest
Journal of Liquid Chromatography and Related Technologies | Year: 2010

Hyphenation of mass spectrometry (MS) to liquid chromatography (LC) represents a powerful tool for qualitative and quantitative characterization of target compounds in very complex matrixes of biological origins. In spite of many advantages due to recent advances and innovations in the area of instrumentation and dedicated software support, some difficulties are still encountered in its current applications. The large variety of functional principles and technical solutions applied for hyphenation of the two techniques, for ion sources, ion extraction and focusing, mass analysis, and ion counting makes it more difficult to obtain perfect agreement between the intrinsic characteristics of the laboratory-available instrumentation and the declared goals of specific determination. This review covers a part of the literature data dealing with the shortcomings of LC/MS in bioanalysis. The following topics are discussed: structural identification and confirmation in LC/MS; precision of the instrumental response over short and long term periods; non-linear response functions; adduct formation in atmospheric pressure ion sources; and carryover effects. Most of the problems arising in LC/MS are related to phenomena occurring during ionization. Obviously, the structural characteristics of the analyzed compounds play an important role, although the principles of ionization within the source and the supporting technical solutions and constructive designs add their own particular features. The complex influence of residual sample matrixes over ionization yields of target compounds and internal standards needs to be studied through proper experimental procedures, in order to control both precision and instrumental response function in analysis of biological samples. Copyright © Taylor & Francis Group, LLC.

Galaon T.,Science LaborMed Pharma S.A. | Mihailciuc C.,University of Bucharest | Medvedovici A.,Science LaborMed Pharma S.A. | Medvedovici A.,University of Bucharest | David V.,University of Bucharest
Journal of Liquid Chromatography and Related Technologies | Year: 2011

Thermodynamic parameters, such as standard enthalpy (ΔH0) and entropic contributions (ΔS0/R+volume phase ratio) of the partition between mobile and stationary phases, for several polar model compounds of pharmaceutical interest, were estimated in RP-LC for different flow-rates and using an octadecyl-silicagel stationary phase. The temperature range used to plot van't Hoff curves was 25-50°C, which is the usual range for separation in RP-LC. Below 20°C, van't Hoff plots become non-linear for all studied compounds, due to the changes of the balance between hydrophobic and solvophobic forces that influence the retention process. Other significant deviations were observed for one compound that is involved in inter-changeable tautomeric equilibria (as discussed for piroxicam). Regression parameters of the linear dependences obtained between retention (natural logarithm of retention factor, ln k') and reciprocal absolute temperature (1/T) together with the estimated phase ratio were used to calculate the thermodynamic parameters of the model compounds. A slight variation was observed when flow-rate was changed within the interval from 0.6 to 2.0mL/min. The enthalpy value decreased with increasing flow-rate up to a minimum at 1.4mL/min; at higher flow-rates these values increased slightly or remained constant. Copyright © Taylor & Francis Group, LLC.

Tanase A.,University of Bucharest | Miu A.,Science Labormed Pharma SA
Revue Roumaine de Chimie | Year: 2012

A simple and high throughput method suitable for routine determination of nickel in magnesium stearate (as pharmaceutical excipient) by GF-AAS with pyrolytic graphite coated tube transversely heated, after simple dissolution of the sample in acidified ethanol, without mineralisation, has been validated. The validation approach directly refers to linearity, detection and quantification limits, characteristic mass, selectivity (matrix effect), precision (repeatability and intermediate precision), accuracy and robustness. Linearity of response was verified for concentrations ranging from 0 to 12 ng/mL of nickel in standard solution in ethanol and was characterized by a correlation coefficient R of 0.9999. Detection limit of the proposed method was found to be 0.84 ng/mL (corresponding to 0.42 μg/g of nickel in the real sample), and the quantification limit was 2.54 ng/mL (corresponding to 1.27 μg/g of nickel in the real sample). The characteristic mass was m0 = 13.62 ± 0.67 pg of nickel. Repeatability and intermediate precision of the method are characterized by relative standard deviations ranging between 2.7 - 6.6% and 5.0 - 9.3%, respectively. Accuracy expressed as recovery gave values ranging between 98.6% and 100.5%. The overall recovery was 99.6%. The robustness was tested by varying the temperatures used for programming the graphite furnace stages and the experimental results were statistically compared through of F-test and Student f-test.

Medvedovici A.,University of Bucharest | Udrescu S.,Science Labormed Pharma SA | David V.,University of Bucharest
Biomedical Chromatography | Year: 2013

Limonene, considered a green solvent, was successfully used to extract simvastatin, lovastatin, and their hydroxy-acid metabolites from human plasma samples. The extraction process was followed by the direct injection of a large volume aliquot (100 μL) from the limonene layer into a Zorbax SB-C18 Rapid Resolution chromatographic column (50mm length×4.6mm i.d. × 1.8μm d.p.), operated under gradient elution reversed-phase separation mechanism. Tandem mass spectrometry operated under the multiple reaction monitoring mode was used for detection, providing low quantitation limits in the 0.25-0.5ng/mL concentration interval. This method was validated and used for quantitation of simvastatin and its hydroxy acid metabolite in incurred plasma samples obtained from two volunteers participating in a bioequivalence study, using lovastatin and its hydroxy analog as internal standards. The results were statistically compared with those produced by means of an alternative RPLC-tandem MS using protein precipitation with acetonitrile. The quality attributes of the two methods are comparatively discussed. The agreement between the quality characteristics of the two methods and the experimental results obtained on real samples may be considered as a consistent basis for the simultaneous use of limonene as extraction medium and injection diluent for hydrophobic compounds in bioanalytical approaches. © 2012 John Wiley & Sons, Ltd.

Albu F.,Science LaborMed Pharma S.A. | Sora I.,Science LaborMed Pharma S.A. | Tache F.,University of Bucharest | David V.,University of Bucharest | And 2 more authors.
Analytical Letters | Year: 2010

Direct plasma loading on a LiChrospher ADS C18 cartridge on-line coupled to an analytical Zorbax XDB C18 column was used to analyze felodipine by means of positive atmospheric pressure chemical ionization (APCI) tandem mass spectrometric (MS/MS) detection. Appropriate sensitivity, accuracy, and precision were obtained using an ion trap mass analyzer operated in a multiple reaction monitoring (MRM) mode. Diethyl-4-(2,3-dichlorophenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate) was used as an internal standard. The method was fully validated. The method was successfully applied to a pilot bioequivalence study made on extended release oral dosage forms containing 10 mg of felodipine, under fed and fasting conditions. © Taylor & Francis Group, LLC.

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