6 results on '"Malenović, Anđelija"'
Search Results
2. Chromatographic behavior of fosinopril sodium and fosinoprilat using neural networks
- Author
-
Medenica Mirjana, Popović Igor, Jančić Biljana, Malenović Anđelija, and Ivanović Darko
- Subjects
forced degradation studies ,Chromatography ,Central composite design ,Artificial neural network ,experimental design-artificial neural networks ,010405 organic chemistry ,Chemistry ,010401 analytical chemistry ,Organic Chemistry ,Clinical Biochemistry ,Reversed-phase chromatography ,01 natural sciences ,Biochemistry ,0104 chemical sciences ,Analytical Chemistry ,Chemometrics ,Fosinopril ,Forced degradation ,Fosinoprilat ,medicine ,column liquid chromatography ,Fosinopril Sodium ,medicine.drug ,fosinoprilat - Abstract
In this paper, the chromatographic characterization of fosinopril sodium and fosinoprilat is presented. The first stept was pK(a) determination for the active substance and its degradation product using RP-LC. It was followed by optimization employing the combination of experimental design and artificial neural networks. For the definition of input and output variables, the central composite design for three factors was built. Back propagation algorithm was applied to model the system, and then the optimization of the experimental conditions was carried out in the neural network with 3-8-2 structure, which confirmed to be able to provide the maximum performance. From the method optimization, the most appropriate experimental conditions for fosinopril sodium and fosinoprilat analysis were extracted. The optimized method was validated and applied in the quality control of tablets and for forced degradation studies.
- Published
- 2008
3. Chemometrical Tools in the Study of the Retention Behavior of Azole Antifungals.
- Author
-
Vemić, Ana, Malenović, Anđelija, Rakić, Tijana, Kostić, Nađa, and Jančić Stojanović, Biljana
- Subjects
- *
CHEMOMETRICS , *LIQUID chromatography , *ARTIFICIAL neural networks , *KETOCONAZOLE , *FLUCONAZOLE - Abstract
Certain chemometrical tools allow an efficient way to provide valuable data to evaluate the retention behavior of analytes in liquid chromatography. In this study of the retention behavior of azole antifungals, the experimental design was applied in combination with artificial neural networks (ANNs). Three potentially significant factors (methanol content, pH of the mobile phase and column temperature) were incorporated in the plan of experiments, defined by central composite design. As the system outputs, the retention factors of all six investigated substances (fluconazole, ketoconazole, bifonazole, clotrimazole, econazole and miconazole) were determined. The pattern for the analyzed behavior of the system was created by employing ANNs. The final, optimized topology of the highly predictive network was 3–8–6. Twelve experiments were used in a training set, whereas a back-propagation algorithm was optimal for network training. The ability of the defined network to predict the retention of the investigated azoles was confirmed by correlations higher than 0.9912 for all analytes. The presented approach allowed the adequate prediction of the retention behavior of azoles, in addition to the extraction of important information for a better understanding of the analyzed system. [ABSTRACT FROM PUBLISHER]
- Published
- 2014
- Full Text
- View/download PDF
4. Microemulsion liquid chromatographic method for characterisation of fosinopril sodium and fosinoprilat separation with chemometrical support.
- Author
-
Jančić, Biljana, Medenica, Mirjana, Ivanović, Darko, Malenović, Anđelija, and Marković, Slavko
- Subjects
HIGH performance liquid chromatography ,EMULSIONS ,SODIUM phosphates ,CHEMOMETRICS ,DRUG dosage - Abstract
The properties of the eluent are the essential factors governing the efficiency in the high-performance liquid chromatography (HPLC) method. A novel approach in retention modelling in the liquid chromatographic separation of fosinopril sodium and its degradation product, fosinoprilat, applying a microemulsion as the mobile phase, was used. The modifications of the mobile phase included the changes to the type of the lipophilic phase, the type and concentration of co-surfactant and surfactant, as well as the pH of the mobile phase. In this study, a full factorial 2
3 design, as the optimal method for screening of the experiment, was applied for selecting factors which had an influence on separation. Optimisation was done by a central composite design. An appropriate resolution with reasonable retention times was obtained with a microemulsion containing 0.9% w/w of cyclohexane, 2.2% w/w of sodium dodecyl sulphate (SDS), 8.0% w/w of n-butanol and 88.9% of aqueous 25 mM disodium phosphate, the pH of which was adjusted to 2.8 with 85% orthophosphoric acid. Separations were performed on an X-Terra 50-mm×4.6-mm, 3.5-μm particle size column at 30°C. UV detection was performed at 220 nm and with a flow rate of 0.3 mL min−1 . The established method was validated and applied for analysis of appropriate tablets. The proposed chromatographic procedure for the separation of fosinopril sodium and its degradation product is less expensive compared with the conventional reversed-phase HPLC method, as well as being simple and rapid. The optimised and validated method can be used for separation, identification and simultaneous determination of fosinopril sodium and fosinoprilat in bulk drug and in pharmaceutical dose forms. [ABSTRACT FROM AUTHOR]- Published
- 2005
- Full Text
- View/download PDF
5. Chemometrically assisted development and validation of LC–MS/MS method for the analysis of potential genotoxic impurities in meropenem active pharmaceutical ingredient.
- Author
-
Grigori, Katerina, Loukas, Yannis L., Malenović, Anđelija, Samara, Vicky, Kalaskani, Anastasia, Dimovasili, Efi, Kalovidouri, Magda, and Dotsikas, Yannis
- Subjects
- *
ANTIBIOTICS , *CHEMOMETRICS , *LIQUID chromatography , *MEROPENEM , *MOBILE phase (Chromatography) - Abstract
A sensitive Liquid Chromatography tandem mass spectrometry (LC–MS/MS) method was developed and validated for the quantitative analysis of three potential genotoxic impurities (318BP, M9, S5) in meropenem Active Pharmaceutical Ingredient (API). Due to the requirement for LOD values in ppb range, a high concentration of meropenem API (30 mg/mL) had to be injected. Therefore, efficient determination of meropenem from its impurities became a critical aim of this study, in order to divert meropenem to waste, via a switching valve. After the selection of the important factors affecting analytes’ elution, a Box-Behnken design was utilized to set the plan of experiments conducted with UV detector. As responses, the separation factor s between the last eluting impurity and meropenem, as well as meropenem retention factor k were used. Grid point search methodology was implemented aiming to obtain the optimal conditions that simultaneously comply to the conflicted criteria. Optimal mobile phase consisted of ACN, methanol and 0.09% HCOOH at a ratio 71/3.5/15.5 v/v. All impurities and internal standard omeprazole were eluted before 7.5 min and at 8.0 min the eluents were directed to waste. The protocol was transferred to LC–MS/MS and validated according to ICH guidelines. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
6. Multikriterijumski pristup optimizaciji hromatografskih metoda za farmaceutsku analizu perindopril t-butilamina
- Author
-
Marija M. Mašković, Ivanović, Darko, Stojanović, Biljana, Malenović, Anđelija, Stanimirović, Zorica, and Dotsikas, Yannis
- Subjects
Chromatography ,perindopril t-butylamine ,Multi–criteria decision–making method ,Plackett–Burman design ,perindopril t-butilamin ,hemometrija ,Plackett–Burman dizajn ,multikriterijumski pristup optimizaciji metode ,chemometrics ,Mathematics - Abstract
Cilj ove doktorske disertacije bio je da se korišćenjem savremene metodologije koja uključuje optimizaciju metode multikriterijmskom pristupom i procenu robusnosti metode upotrebom eksperimentalnog dizajna, razviju metode reverzno–fazne i mikroemulzione tečne hromatografije za analizu perindopril t-butilamina i njegovih nečistoća (perindoprilat, Y31, Y32 i Y33). U prvom delu doktorske disertacije opisan je razvoj metode reverzno–fazne tečne hromatografije za analizu ispitivanih jedinjenja. Uzimajući u obzir savremeni koncept kojim se obezbeđuje razvoj metode odgovarajućih karakteristika, u fazi optimizacije metode primenjen je centralni kompozicioni dizajn sastavljen iz punog faktorskog dizajna 24, zvezda dizajna sa tačkama 0,5 sa 4 ponavljanja u centralnoj tački, kojim je ispitan uticaj faktora (sadržaj acetonitrila u mobilnoj fazi, pH mobilne faze, temperatura kolone i brzina protoka mobilne faze) na odabrane odgovore sistema. Na osnovu dobijenih matematičkih modela izvedeni su zaključci o uticaju faktora ali ne i o globalnom optimumu u ispitivanom eksperimentalnom području. U tom cilju, primenjen je multikriterijumski pristup tj. Deringerova funkcija poželjnih odgovora. Rezultati su omogućili definisanje globalnog optimuma a subjektivni parametri ispitani su primenom analize osetljivosti čime je potvrđen adekvatan izbor optimalnih uslova. Nakon toga, procenjena je robusnost postavljenog optimuma primenom pristupa koji uključuje primenu eksperimentalnog dizajna. Robusnost metode reverzno–fazne tečne hromatografije procenjena je primenom Plackett–Burman dizajna kojim je kroz 12 eksperimenta ispitano 7 pravih faktora a u cilju kompletiranja matrice eksperimenta dodata su 4 veštačka faktora (dummies). Analiza rezultata primenom statističkih i grafičkih metoda potvrdila je odgovarajuću robusnost optimuma a na osnovu rezultata su određeni i intervali neznačajnosti za značajne faktore, kao i parametri za procenu pogodnosti sistema razvijene metode reverzno–fazne tečne hromatografije za analizu perindopril t-butilamina i njegovih nečistoća (perindoprilat, Y31, Y32 i Y33). Na kraju, ispitani su i ostali parametri validacije i metoda je primenjena za analizu tableta sa perindopril t-butilaminom... The goal of this doctorial dissertation was the development of reversed phase high performance liquid chromatography (RP–HPLC) as well as microemulsion liquid chromatography (MELC) methods for the analysis of perindopril t-butylamine and its impurities (perindoprilate, Y31, Y32 and Y33), by using contemporary approaches such as Multi-criteria decision-making method (MCDM) for methods optimisation and experimental design for methods robustness assessment. Development of RP–HPLC method for the analysis of the investigated compounds was desribed in the first part of the doctorial dissertation. Taking into account the modern concept that ensures development of the method with appropriate characteristics, Central Composite Design (CCD) with 24 full factorial design, 0,5 star design and 4 replicates in central point, was chosen for the method optimisation. Previously described CCD was applied for examination of factors (acetonitrile content in the mobile phase, pH of the mobile phase, column temperature and flow rate of the mobile phase) effects on chosen system responses. Based on the defined mathematical models, conclusions on factor effects were drawn, but not on the global optimum within the examined experimental domain, as well. In that aim, multicriteria approach, i.e. Derringer’s desirability function was applied. Results obtained enabled defining of global optimum. Since desirability function itself includes subjective parameters, Sensitivity Analysis was applied which confirmed adequate selection of optimal conditions. After that, robustness of the optimum set was examined by applying experimental design. Robustness of the RP–HPLC method was assessed by applying Plackett–Burman design for examining seven real factors by 12 experiments. Besides seven real factors, 4 dummy factors were included in order to complete the plan of the experiments. Analysis of the results obtained performed by statistical and graphical methods confirmed appropriate robustness of the optimum. In addition, for effects estimated to be significant, non–significant intervals were calculated as well as parameters for the assessment of system–suitability for the developed RP–HPLC method for the analysis of perindopril t-butylamine and its impurities (perindoprilate, Y31, Y32 and Y33). Finally, method validation parameters were examined, after which the method was applied for the analysis of perindopril t-butylamine tablets...
- Published
- 2014
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.