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Open access

Silvia Imre, Klára Kacsó and Daniela-Lucia Muntean

Abstract

Introduction: This study proposes the simultaneous determination of atorvastatin and amlodipine in industrial tablets by a quantitative spectrophotometric method, named the apparent content curve method, test method, and by an HPLC method with UV detection as reference method.

Materials and methods: A synthetic mixture and two fixed medicinal combinations containing amlodipine and atorvastatin were investigated by the apparent content curve method, a simple and relatively inexpensive UV-VIS spectrophotometric method based on a mathematical approach derived from the Lambert-Beer law. The results were compared with those obtained by an HPLC method.

Results: A good correlation of the results was obtained, the difference between the pair results was not significant (p >0.05).

Conclusions: The proposed spectrophotometric method is an easier and cheaper alternative for the quantitative determination of amlodipine and atorvastatin in industrial fixed-dose combinations.

Open access

László Ferencz and Daniela Lucia Muntean

Abstract

The rodenticide brodifacoum is highly toxic to mammals and birds, and extremely toxic to fish. It is a highly cumulative poison due to its high lipophilicity and extremely slow elimination. For this reason, it may be interesting to find similar compounds in order to enlarge the spectrum of vitamin K epoxide reductase enzyme inhibitors used today in pest control. We used the Similar Compounds search type of the Chemical Structure Search of the PubChem Compound Database to locate records that are similar to the chemical structure of brodifacoum, using pre-specified similarity thresholds. Using the threshold ≥ than 95% for the similar structures criteria, we found 14 compounds (from over 30 million entries) that meet this criteria. Two of these compounds have a better binding affinity to vitamin K epoxide reductase enzyme than brodifacoum, but the binding energy of the other 12 substances is also high, having identical or lower lipophilicity; consequently, they will eliminate faster, possibly lacking a part of the adverse effects.

Open access

Ion Valentin, Imre Silvia, Cârje Anca Gabriela and Muntean Daniela Lucia

Abstract

Introduction: Perindopril, as an angiotensin converting enzyme inhibitor and indapamide, as a thiazide like diuretic, can be administrated together for the treatment of high blood preasure and other cardiovascular diseases. The aim of this study was to develop two simple and reliable separation methods for perindopril and indapamide by high performance liquid chromatography and capillary zone electrophoresis in order to evaluate their behaviour under separation conditions, for simultaneous separation.

Materials and methods: Standard solutions of perindopril erbumine and indapamide in proper solvents were analized. An Agilent 1100 series HPLC system was used for the separation of the two analytes on a C18 stationary phase (Zorbax Stable Bond 3.5 µm), under an isocratic elution. As a comparative method, an Agilent 7100 series capillary electrophoresis system was used for the development of the electrophoretic method.

Results: Both developed methods turned to comply to the separation performance parameters such as resolution and selectivity, with low limits of detection, wide range of liniarity. No statistical difference concerning precision of the qualitative parameters was observed. Time analysis less than 5 minutes both for chromatographic and electrophoretic separations proved to generate cost and time effective analysis methods.

Conclusions: Two analytical methods, HPLC and CZE respectively, for the separation of perindoprile erbumine and indapamide have been successfully developed, both recording satisfactory analytical parameters.

Open access

Şerban Andrei Gâz Florea, Adriana Gâz Florea, Hajnal Kelemen and Daniela-Lucia Muntean

Abstract

As more data are generated from proteome and transcriptome analysis revealing that metalloproteinases represent most of the Viperid and Colubrid venom components authors decided to describe in a short review a classification and some of the multiple activities of snake venom metalloproteinases. SVMPs are classified in three major classes (P-I, P-II and P-III classes) based on the presence of various domain structures and according to their domain organization. Furthermore, P-II and P-III classes were separated in subclasses based on distinctive post-translational modifications. SVMPs are synthesized in a latent form, being activated through a Cys-switch mechanism similar to matrix metalloproteinases. Most of the metalloproteinases of the snake venom are responsible for the hemorrhagic events but also have fibrinogenolytic activity, poses apoptotic activity, activate blood coagulation factor II and X, inhibit platelet aggregation, demonstrating that SVMPs have multiple functions in addition to well-known hemorrhagic function.

Open access

C.E. Vari, H. Suciu, Mihaela Ispas, S. Voidăzan and Daniela Lucia Muntean

Abstract

In a retrospective study, the safety profile and efficacy of immunosuppressive medication was evaluated in 35 patients with cardiac transplant in Targu Mures during 1999-2011 (11 treated with cyclosporine, 24 with tacrolimus, both drugs were associated with mycophenolate mofetil). Therapeutic benefit was measured by survival curve and lack of rejection while safety was evaluated by measuring plasma immunosuppressive drugs levels and evaluation of specific adverse events (nephrotoxicity, diabetes, and hypertension). The most frequent side effect was nephrotoxicity (significant reduction in glomerular filtration rate estimated by MDRD formula), but no significant differences were found between the 2 medications.

Open access

Erzsébet Fogarasi, Mircea Dumitru Croitoru, Ibolya Fülöp and Daniela-Lucia Muntean

Abstract

Oxidative stress is an imbalance between free radicals or other reactive species and the antioxidant activity of the organism. Oxidative stress can induce several illnesses such as cardiovascular disease, neurodegenerative disorders, diabetes, cancer, Alzheimer and Parkinson. The biomarkers of oxidative stress are used to test oxidative injury of biomolecules. The indicators of lipid peroxidation (malondialdehyde, 4-hydroxy- 2-nonenal, 2-propenal, isoprostanes), of protein oxidation (carbonylated proteins, tyrosine derivatives), of oxidative damage of DNA, and other biomarkers (glutathione level, metallothioneins, myeloperoxidase activity) are the most used oxidative stress markers. Diseases caused by oxidative stress can be prevented with antioxidants. In human body are several enzymes with antioxidant capacity (superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase) and spin traps. Antioxidants are synthetized in the organism (glutathione) or arrive in the body by nutrition (ascorbic acid, vitamin E, carotenoids, flavonoids, resveratrol, xanthones). Different therapeutic strategies to reduce oxidative stress with the use of synthetic molecules such as nitrone-based antioxidants (phenyl-α-tert-butyl-nitrone (PBN), 2,4-disulphophenyl- N-tert-butylnitrone (NXY-059), stilbazulenyl nitrone (STAZN), which scavenge a wide variety of free radical species, increase endogenous antioxidant levels and inhibits free radical generation are also tested in animal models.

Open access

Alina Balint, Anca Gabriela Cârje, Daniela Lucia Muntean and Silvia Imre

Abstract

Objective: The aim of the study was to compare the influence of mobile phase composition and temperature on chiral separation of racemic ibuprofen by capillary electrophoresis and high performance liquid chromatography with UV detection. Materials and methods: Racemic ibuprofen was analysed on a chiral OVM column with an HPLC system 1100 Agilent Technologies, under isocratic elution, by using potassium dihydrogen phosphate 20 mM and ethanol in mobile phase. The flow rate was set at 1 mL/min, UV detector at 220 nm and different column temperatures were tested. For electrophoresis separation an Agilent CE G1600AX Capillary Electrophoresis System system, with UV detection, was used. The electrophoresis analysis was performed at different pH values and temperatures, with phosphate buffer 25 mM and methyl-β-cyclodextrin as chiral selector. Results: The chromatograhic analysis reveals a high influence of mobile phase pH on ibuprofen enantiomers separation. An elution with a mixture of potassium dihydrogen phosphate 20 mM pH=3 and ethanol, at 25°C, allowed enantiomers separation with good resolution in less than 8 min. Conclusions: The proposed HPLC method proved suitable for the separation of ibuprofen enantiomers with a good resolution, but the capillary electrophoresis tested parameters did not allow chiral discrimination.

Open access

Csifo Enikő, Croitoru M. D., Fülöp Ibolya and Muntean Daniela-Lucia

Abstract

Objectives: A simple, quick and low cost HPLC-UV method for assay of meloxicam in plasma and pharmaceutical dosage forms was developed.

Methods: Separation and assay of meloxicam, using a simple reverse phase HPLC-UV method was achieved using an Agilent Zorbax SB C18 column, with methanol and 1% aqueous solution of glacial acetic acid as mobile phase. Elution was performed with composition gradient, meloxicam being detected at 355 nm with a 5 minutes analysis time. The method was tested on human plasma and pharmaceutical dosage forms.

Results: The retention time of the meloxicam was 3,7 minutes. Regression analysis showed good linearity, with correlation coefficient R= 0,9997; linear regression equation: y = 206,1x -77,5 over the 20-2000 ng/ml concentration range. Limit of detection was determined to be 5 ng/ml and limit of quantification was set at 15 ng/ml. The recovery of the analyte in human plasma was low: 30,50%, however it was reproducible, with a coefficient of variation of 4,83%. The analysis of the tablets resulted in a 85,82% of meloxicam compared to the declared concentration.

Conclusions: The method proposed is quick, simple and adequate for detecting the meloxicam in human plasma. Although the recovery rate was low, it was reproducible, which leads to the fact, that improving extraction procedure can optimize the method.

Open access

Lavinia Grama, Daniela-Lucia Muntean and A Curticăpean

Abstract

Background: Polyanions are a special category of coordination compounds with a large development in last years. By coordination of metal oxoions at the lacunary polyoxometalates are obtained new compounds which are studied for theirs possible antitumoral and antiviral activities. The polyoxometalates can bind cations by oxygen atoms from their saturated surface structure or by embedding in vacant sites.

Material and method: The methods used for determining cation coordination with the unsaturated polyoxotungstate are spectrophotometry and conductometry. The solutions used in this study were: for ligand a solution of K27[KAsW40O140] and for cation a solution of K2[PtCl6]. The variation of electrical conductivity of ionic species found in solution, caused by their concentrations, decreases during the complex formation, which was determined by conductometry. The spectrophotometric assay was performed to verify ratios between cation:ligand combination, determined by conductometry.

Results: The graphical representations of conductivity function of number of moles of added titrant solutions emphasize that there are two types of coordination compounds with two different combination ratios ligand:cation at 1:2 or 1:4. The spectrophotometric determination performed, confirmed these ratios.

Conclusions: There are two types of coordination complexes, and the ligand:cation ratios are well known for encrypting polyoxotungstates type used in the study. Besides the main active position SC where K+ alkaline cation is coordinated, it has four active stand side S1-4, which can coordinate metal cations, depending on the size of their cationic radius and the electronic charge they hold.

Open access

Mircea Dumitru Croitoru, Ibolya Fülöp, Erzsébet Fogarasi and Daniela-Lucia Muntean

Abstract

A method of measuring in vivo nitric oxide (NO) levels is required to detect pathological conditions in which endogenous production is decreased or to identify agents able to release this biomolecule. Unfortunately, nitric oxide has a very short biological half-life and is very difficult to measure. Assay of the oxidative products’ of NO levels, nitrite (NO2 -) and nitrate (NO3 -), measured as total amount, after the reduction of nitrate to nitrite, determined after conversion in an azo dye, is usually the used method, named NOx test. The NOx test is frequently used as a NO biomarker in human studies and also in animal experiments. The aim of this work is to evaluate the suitability of the NOx test for the detection of an instant release of nitric oxide.

Rabbits were used as experimental animals, a validated HPLC-UV/VIS method was used for speciation of nitrite and nitrate. The following substances were administered: blank; “negative blank”: phenyl-N-tert-butylnitrone (PBN); “positive blank” (nitroglycerin); nitrite.

PBN administration significantly increased nitrate and decreased nitrite levels, nitrite administration excessively increased nitrate levels, while nitroglycerin (1 mg/kg) significantly increased both nitrate and nitrite levels.

Results show that NOx test cannot be considered accurate in acute nitric oxide status testing. Nitrite alone should be used as an in vivo released nitric oxide marker.