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  • Author: Amelia Tero-Vescan x
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Hancu Gabriel, Tero-Vescan Amelia, Filip Cristina and Rusu Aura

Abstract

The aim of this study to inventory the main electrophoretic methods for identification and quantitative determination of fatty acids from different biological matrices. Critical analysis of electrophoretic methods reported in the literature show that the determination of polyunsaturated fatty acids can be made by: capillary zone electrophoresis, micellar electrokinetic chromatography and microemulsion electrokinetic chromatography using different detection systems such as ultraviolet diode array detection, laser induced fluorescence or mass – spectrometry. Capillary electrophoresis is a fast, low-cost technique used for polyunsaturated fatty acids analysis although their determination is mostly based on gas chromatography.

Open access

Alexandru Robert Vlad, Gabriel Hancu, Hajnal Kelemen, Diana Ciurcă and Amelia Tero-Vescan

Abstract

Sibutramine is a chiral anti-obesity drug which decreases food intake and increases energy expenditure. In therapy it is used as a racemic mixture; however both pharmacokinetic and pharmacodynamic data have revealed enantioselective behavior of sibutramine and its major active metabolites. Several chromatographic and electrophoretic analytical methods have been published so far for the chiral determination of sibutramine from pharmaceutical preparations and biological samples. The current paper aims to provide a systematic review of the stereochemical aspects and analytical methods used for the enantiodetermination of sibutramine and its active enantiomers covering the last 15 years.

Open access

George Jîtcă, Bianca-Eugenia Ősz, Szende Vancea, Amalia Miklos and Amelia Tero-Vescan

Abstract

Objective: The purpose of this study was to develop a LC-MS method to determine amiodarone (AMI) and its major metabolite desethylamiodarone (DEA) from rat plasma released from the adipose tissue of AMI treated rats subjected to a weight gain/weight loss cycle. Methods: Separation of the compounds was performed on a Kinetex 2.6 μm C18 100 x 4.6 mm column under isocratic conditions using a mixture of acetonitrile: 0.1% formic acid 65:35 at a flow rate of 0.5 ml/min. Detection of the analyte was performed by electrospray positive ionization, the monitored ions being 135 m/z from 646 for AMI and 135 m/z of 618 for DEA. Analytes were extracted after plasma protein precipitation with methanol. Results: The developed method presented specificity and linearity on the concentration range of 25-2500 ng/ml plasma for AMI and 2.5-1250 ng/ml plasma for DEA and the precision and accuracy of the method at all of quality control concentration levels including LLOQ were according to official guidelines for validating analytical methods. Conclusions: A sensitive and accurate LC-MS method has been developed with a much lower LLOQ than literature data to detect the plasma concentration differences of the studied analytes that result from forced lipolysis and mobilization from the adipose tissue.

Open access

Amelia Tero-Vescan, Camil-Eugen Vari, Daniela-Lucia Muntean, Maria-Titica Dogaru, Cristina Filip and Silvia Imre

Abstract

A simple and selective method for genistein (GNST) determination in rat liver and kidney was validated in order to study the phytoestrogenic effect of GNST in ovariectomised female Wistar rats. GNST was separated on a Kromasil 100-RP8 column, 150 mm x 4.6 mm, 5 mm equipped with a Kromasil RP 8 precolumn. The mobile phase was 55:45 (v / v) phosphoric acid, 15 mmol in water: methanol at a flow rate of 1.3 ml / min. Luteolin 20 μg / ml in methanol was used as internal standard (IS). The retention time of GNST was tR = 13.22 min and tR =11.60 min for the IS. Calibration curves in the range 40-400 μg GNST/100g liver and 20-200 μg GNST/100g kidney presented a coefficient of determination higher than 0.99. The method developed presented a good precision and accuracy at the lower limit of quantification LLOQ. 10 white Wistar female rats, 8 weeks of age were treated s.c. with 10 mg GNST/kg bw/day for 8 weeks, while a group of 10 animals were used as controls. The values obtained for GNST in the liver were 192.12 ± 53.46 μg/100g and 74.51 ± 12.77 μg/100g in kidney samples.

Open access

Silvia Imre, Timea Haidu, Oana Ponta, Szende Vancea, Camil-Eugen Vari and Amelia Tero-Vescan

Abstract

Objective: The aim of the study was a comparative investigation by spectral and thermal analysis in order to asses a number of characteristics of different varieties ofrawmaterials of ursodeoxycholic acid and ibuprofen. The different dissolution behavior of two ursodeoxycholic acid pharmaceutical product by crystallinity pattern was investigated. Methods: Raw materials of ursodeoxycholic acid and ibuprofen were used. IR spectroscopy, differential scanning calorimetry and X-Ray Diffraction Analysis were applied. Results: The results show no crystallinitydifferences for different batches of the tested drugs. No solid solid transition was proved during sample preparation for transmission IR analysis. Conclusions: A combination of two more affordabletests by IR spectrometry and differential scanning calorimetry lead to the same results as X-Ray diffraction analysis for crystallinity similarity assessment of the studied substances. The dissolution differences of test drugs were not related to the polymorphism of the raw materials.

Open access

Saracut Claudiu, Molnar Calin, L Farczádi, L Vlase, Tero-Vescan Amelia, Todoran Nicoleta and Copotoiu Constantin

Abstract

Objectives: The aim of the study was to determine the level of secondary bile acids (SBA) in the diets and feces of mice and the variation of amount ingested/excreted if these SBA are administered as monotherapy or in 1:1 dose.

Methods: The mice were divided into 4 groups and fed for 140 days with different diets. The control lot received a normal diet and the others received diets supplemented with 0.25% deoxycholic acid (DCA), 0.25% lithocholic acid (LCA) and 0.125% DCA+0.125% LCA. After 140 days, the mice feces were collected and homogenized to obtain a mixture for each lot from which the determinations of the studied SBA were performed. For the mice food evaluation, portions of 10 g from each of the 4 diets were subjected to the SBA determination.

Results: The daily ingestion over more than 4 months of DCA or LCA added to the diet and administered as monotherapy determine a significantly increase of the SBA eliminated into the feces (the DCA level was 11x higher, and of the LCA 233x higher). If half of the LCA dose is replaced with DCA, the level of LCA in the feces gets comparable with that of the DCA (their combined amounts represents only 13x higher increase of these two bile acids in feces).

Conclusions: The simultaneous ingestion and excretion of DCA and LCA can be considered as a particular situation ruled by endogenous mechanisms. This behavior represents an important observation, knowing that the bile acids effects in the colorectal cancer are dose dependent.

Open access

Amelia Tero-Vescan, Bianca-Eugenia Osz, Camil-Eugen Vari, Silvia Imre and Gabriel Hancu

Abstract

Objectives: The purpose of the study was to determine the omega-3/omega-6 ratio in swine brain homogenate by HPLC with UV detection and to discuss the values obtained by comparison to the human species. Materials and methods: Determinations were performed by HPLC method using as mobile phase an isocratic mixture (A:B - 5:95) of mobile phase A = 25% acetonitrile in water and B = acetonitrile with a flow-rate of 1.2 mL/min and UV detection at 205nm. Chromatographic column: Phenomenex C8 150x4.6 mm 5μm. 50 g swine brain was hydrolyzed with 100 mL 0.5N HCl, the organic phase was extracted in 50 mL hexane, concentrated by evaporation and resumed in 200 μL acetonitrile. Results: Polyunsaturated fatty acids were separated as follows arachidonic acid (AA) - Rt = 2.69 min, docosahexaenoic acid (DHA) - Rt = 3.12 min and eicosapentaenoic acid (EPA) - Rt = 3.97 min. The following omega-3/omega-6 ratios were calculated (DHA + EPA)/ AA = 0.572 ± 0.451, EPA/AA = 0.027 ± 0.015 and DHA/AA = 0.689 ± 0.612. Conclusions: The values obtained for these ratios should be balanced, but in reality they are in favor of the ratio denominator. Considering the physiological and nutritional similarities and that an accurate diagnosis of neurodegenerative disease is set in post-mortem, swine brain homogenate could serve as an animal model for human nervous tissue.