Brezovska, Katerina

Preferred name

Brezovska, Katerina

Official Name

Brezovska, Katerina

Main Affiliation

kami@ff.ukim.edu.mk

Now showing 1 - 10 of 30

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Root causes for presence of nitrosamine impurities in active pharmaceutical substances and finished pharmaceutical products
(Macedonian Pharmaceutical Association, 2022-12-31)
Prculovska, Milena
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Poceva Panovska, Ana
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Dimtirovska, Aneta
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Development and optimization of a generic HPLC method for the simultaneous determination of common ingredients in multi component cough and cold oral drug products using chemometrics
(Macedonian Pharmaceutical Association, 2018)
Zafirova, Marija
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Ugrinova, Liljana
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Petrovska-Dimitrievska, Gabriela
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Karchev, Vasil
<jats:p>The aim of this work was to develop a single, generally applicable high performance liquid chromatography/diode array detector (HPLC/DAD) method for simultaneous determination of the most frequently used cough and cold active substances and their impurities that would be applicable for a number of possible formulation compositions of cough and cold medicines. The compounds that are separated by the method include eleven active substances: paracetamol, phenylephrine HCl, caffeine, ibuprofen, ascorbic acid, propiphenazone, pheniramine maleate, chlorphenamine maleate, pseudoephedrine HCl, dextromethorphan HBr and cetylpyridinium Cl; five of their impurities: 4-aminophenol, 4-nitrophenol, 4`-chloroacetanilide, chlorphenamine impurity C and ephedrine HCl; and two preservatives: sodium benzoate and propyl parahydroxybenzoate. All 18 compounds were successfully separated on a reversed phase (RP)-HPLC column with superficially porous particles using gradient elution with a very simple mobile phase in 14 minutes with excellent sensitivity and resolution. Method optimization was performed by the design of experiments approach. The proposed method has been validated according to ICH guidelines and proved to be suitable for the simultaneous qualitative and quantitative determination of the selected compounds in different cough and cold dosage forms. Keywords: cough and cold active substances and impurities, HPLC/DAD, superficially porous particles, core-shell particles, chemometrics, design of experiments</jats:p>
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Regulatory approaches for medicines containing established active substances in USA
(Macedonian Pharmaceutical Association, 2020-10-29)
Danilova, Bojana
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Tonic Ribarska, Jasmina
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Trajkovic Jolevska, Suzana
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Lazova, Jelena
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Development of a stability-indicating method for evaluation of impurity profile of Atorvastatin film-coated tablets using cyano column based on core-shell technology
(Society of Chemists and Technologists of Macedonia, 2022-06-30)
Trajchova Kovachovska, Elena
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Trajkovic, Stefan
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Mitrevska, Ivana
<jats:p>This research highlights the specificity of the new stability-indicating method developed to evaluate the impurity profile of Atorvastatin film-coated tablets. The proposed method has the ability to capture any possible changes that may occur during the stability studies over time and under different stress factors, and is selective enough to enable quality control of finished product from different suppliers of active pharmaceutical ingredient (API)/excipients. Satisfactory critical peak resolution between specified and unspecified impurities was achieved using the fused-core shell technology and extensively endcapped diisopropyl-cyanopropylsilane stationary phase (Halo ES-CN 150 mm × 4.6 mm, 2.7 µm), with a 10 mM ammonium formate buffer pH 3.5 and acetonitrile as mobile phase. A potential worse case impurity profile was assumed by using retained samples combined with the data obtained for samples manufactured with APIs from different suppliers exposed to the forced degradation study. The mass balance for stressed samples demonstrated the stability-indicating capability of the proposed method.</jats:p>
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Possibilities and challenges of "green" chromatographic solutions
(Macedonian Pharmaceutical Association, 2022-12-31)
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Immunoproteomic identification of antigenic candidate Campylobacter jejuni and human peripheral nerve proteins involved in Guillain-Barré syndrome
(Elsevier BV, 2018-04-15)
Loshaj-Shala, Aida
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Colzani, Mara
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Poceva Panovska, Ana
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Suturkova, Ljubica
Immunoproteomics is become a potent methodology used for identifying immunoreactive proteins. In this study, an immunoproteomic approach based on 2-dimensional gel electrophoresis (2D-PAGE) and immunoblotting combined with high resolution mass spectrometry (MS) was used to identify immunoreactive proteins that might be involved in mechanisms of Guillain-Barré syndrome (GBS) development, regardless of their potential reciprocal molecular mimicry. Proteins isolated from C. jejuni and human peripheral nerve tissue (HPN) were separated with 2D SDS-PAGE and subjected to western blotting using serum samples from GBS patients. The peptides generated after proteolysis of the immunoreactive proteins were submitted to nanoflow-high performance liquid chromatography-nano electrospray ionization coupled to high resolution mass spectrometry (nHPLC-nESI-MS and MS/MS) followed by SEQUESTdata analysis for proteins identification. In C. jejuni, immunoreactivity was found for GroEL and DnaK, structural proteins (MOMP), key enzymatic proteins necessary for the microbial proliferation (adenylate kinase, enolase, inorganic pyrophosphatase and aspartate ammonia-lyase), and antioxidant enzymes (alkyl hydroperoxide reductase-AhpC and DNA protection during starvation protein - DNA protection factor against Fe2+-mediated oxidative stress). HPN immunoreactive proteins identified were heat shock proteins (HSP), intermediate filaments (vimentin and desmin), and other proteins and enzymes such as troponin/tropomyosin complex and ATP synthase subunit beta and the keratan sulfate proteoglycan lumican. The targeting of vimentin and desmin, suggested that the neuronal autoimmune damage is specifically directed to intermediate neuronal (vimentin) and neuromuscular IF, probably localized nearby cell surface, affording increased accessibility to autoantibodies. These findings suggest that the post-infectious development of GBS may be also associated to additional concomitant immune factors that lead to nerve damage generated by auto-immune trigger(s) different from molecular mimicry.
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Green RP-HPLC method for impurity profile of amlodipine in tablets
(Centre for Evaluation in Education and Science (CEON/CEES), 2024)
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Godzo, Hrisanta
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Atanasovska, Biljana
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Zafirova-Gjorgievska, Marija
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<jats:p>Increased awareness of nature preservation has encouraged the introduction of the green analytical chemistry (GAC) practice concepts concerning several important aspects, including sustainable development, environmental impact, and minimum waste. The aim of this research was to contribute to the implementation of this approach for the pharmaceutical industry while retaining the crucial aspects and strict requirements of quality control of medicines. Therefore, an ethanolbased, green and robust high-performance liquid chromatography (HPLC) method for the determination of related substances of amlodipine (AML) in film-coated tablets was developed and optimized using the Design of Experiments (DoE). The chromatographic separation was performed on an RP-select B column (250 x 4.0 mm, 5 mm), using a mixture of 0.04 M sodium dihydrogen phosphate monohydrate (pH 4.0) and ethanol (60:40 % v/v) as a mobile phase. The optimized conditions provided the separation of two specified impurities (impurity D and impurity F). The selectivity of the method was confirmed using forced degradation studies. The Analytical Eco-scale approach and AGREE metrics confirmed that the method conforms to the GAC principles. The validated method was successfully applied for the determination of related substances in three samples from the market, demonstrating the applicability of the method in routine analysis.</jats:p>
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Greenness Assessment and Validation of HPLC Method for Simultaneous Determination of Resveratrol and Vitamin E in Dietary Supplements
(Oxford University Press (OUP), 2024-03-01)
Topkoska, Marina
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Miloshevska, Martina
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Piponski, Marjan
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Slaveska Spirevska, Irena
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There is an increasing interest in the use of a combination of trans-resveratrol and vitamin E in dietary supplements. Determination of the content of both components is essential for confirmation of the quality of the product.
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Chromatographic and Surfactant Based Potentiometric Determination of Aqueous Dissociation Constant of Mupirocin
(Bentham Science Publishers Ltd., 2020-02-11)
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Karchev, Vasil
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<jats:sec> <jats:title>Background:</jats:title> <jats:p>The available data concerning aqueous dissociation constant of mupirocin (sparingly soluble drug) are scarce. In this study, chromatographic, surfactant based potentiometric concept and spectrophotometric method were used for determination of the aqueous pKa value of mupirocin.</jats:p> </jats:sec> <jats:sec> <jats:title>Methods:</jats:title> <jats:p>Different approaches were used for estimation of the aqueous pKa value from the apparent pKa values obtained at four ACN concentrations, ranging from 22% to 30%. The potentiometric determination of the pKa value of mupirocin was performed using different concentration of Tween 80 as a surfactant.</jats:p> </jats:sec> <jats:sec> <jats:title>Results:</jats:title> <jats:p>The aqueous pKa value of mupirocin, determined for the first time by reverse-phase liquid chromatography method, was found to be 4.76. The obtained value was confirmed by potentiometric method (4.85). It was found that Tween 80 increases the pKa values. The linear relationship between the apparent pKa values and the surfactant concentrations was used as an approach for estimation of the aqueous pKa value. Both methods gave similar values for aqueous pKa which correspond with the theoretically obtained pKa value (4.88) using Pallas computer program. It was found that mupirocin gives pH-indipendent spectra, thus spectrophotometric method is not applicable for determination of pKa of this compound.</jats:p> </jats:sec> <jats:sec> <jats:title>Conclusion:</jats:title> <jats:p>This comprehensive approach used for the pKa determination enable us to obtained reliable results for the aqueous pKa value of mupirocin. The linear relationship between the pKa values and the nonionic surfactant concentrations could be used as a reliable and simple approach for determination of aqueous pKa value of sparingly soluble drugs.</jats:p> </jats:sec>
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Development and Validation of an SEC-HPLC Method for the Analysis of Lenogratsim (rHuG-CSF) in Pharmaceutical Formulations
(Informa UK Limited, 2009-10-05)
Tonic-Ribarska, Jasmina
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Trajkovic-Jolevska, Suzana

Brezovska, Katerina

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