86 research outputs found
OdreÄivanje SeptalenĀ® pastila primenom derivativne spektrofotometrije
In this paper, a second-derivative spectrophotometric method of assaying SeptalenĀ® pellets (Krka, Novo Mesto, Slovenia), which contain lidocaine 1 mg, and cetrimoniumbromide 2 mg, is described. Lidocaine, 2-(diethylamino)-N-(2,6-dimethyl-phenyl)-acetamide, is a local anesthetic with pronounced antiarhythmic and anticonvulsant properties. Cetrimoniumbromide, N,N,N-trimethyl-l-hexadecanaminium bromide, is a topical antiseptic and cleansing agent. Lidocaine was determined at 250 nm using the "zero crossing" technique because the signals of centrimonium bromide and the colour ingredient are zero at this wavelength. Cetrimonium bromide was determined by correction of the peak amplitude at 215 nm according to lidocaine. In choosing the optimal magnitudes for the simultaneous determination of both drugs, the following criteria were considered: (1) the linearity of the calibration graphs as given by the correlation coefficients, (2) the intercept, (3) the sensitivity as given by the regression coefficient, (4) the degree of interference in the derivative measurement by the presence of the other compound, as given by the relative percent error and by the relative recovery, and (5) the reproducibility, as given by the coefficient of variation, calculated by recording the second-derivative spectra.U ovom radu opisana je derivativna spektrofotometrija izvoda drugog reda za odreÄivanje SeptalenĀ® pastila (Krka, Novo Mesto, Slovenija), koje sadrže lidokain 1 mg, i cetrimonijum-bromid 2 mg. Lidokain, 2-(dietilamino)-N-(2,6-dimetil-fenil)-acetamid, je lokalni anestetik sa izrazitim antiaritmiÄnim i antikonvulzivnim osobinama. Cetrimonijum-bromid, N,N,N-trimetil-1-heksadekanaminijum-bromid je povrÅ”inski antiseptik i agens za ÄiÅ”Äenje. Lidokain je odreÄivan na talasnoj dužini od 250 nm koriÅ”Äenjem metode "nultog preseka", jer su signali za cetrimonijum-bromid i boju bili nula na toj talasnoj dužini. Cetrimonijum-bromid je odreÄivan metodom korekcije na 215 nm u odnosu na lidokain. Prikazani su rezultati odreÄivanja aktivnih komponenti SeptalenĀ® pastila u prisustvu boje ili sa prethodnim obezbojavanjem. Pod izabranim eksperimentalnim uslovima odreÄeni su i sledeÄi kriterijumi za optimizaciju predložene derivativne spektrofotometrijske metode: (1) linearnost kalibracione krive data je korelacionim koeficijentom, (2) presek sa ordinatom, (3) osetljivost je data regresionim koeficijentom, (4) uticaj prisustva ostalih komponenti na derivativna merenja dat je relativnom greÅ”kom i "recovery" vrednoÅ”Äu i (5) reproduktivnost je data koeficijentom varijacije
OdreÄivanje sadržaja pseudoefedrina, paracetamola i askorbinske kiseline u peroralnom praÅ”ku primenom reverzno-fazne teÄne hromatografije
For the simultaneous analysis of multicomponent mixture containing pseudoephedrine, paracetamole and ascorbic acid two RP-HPLC methods were developed. Separation were performed on Hewlett Packard 1100 system which consisted of HP 1100 binary pump, HP 1100 UV/VIS detector and HP ChemStation for the automatic data evaluation. Methods were developed, e. g. chromatographic conditiond settled, methods submited to method validation and then applied for the determination of content of multicomponent powder.The best separation was achived on Platinium Alltech Amino 150 x 4.6 mm, 5 mm particle size column, at 30Ā°C. Injection volume was 20mL. Mobile phase in mehtod I was a mixture of methanol-water (30:70 V/V), pH 2.5, and in mehtod II was a mixture methanol-water (60:40 V/V), pH 2.9. pH of the mobile phases were adjusted with 85% ortophosphoric acid. Detection was performed at 214 nm in mehtod I and at 257 nm in method II. Flow rate was 1 mLmin-1. Developed methods were validated. Obtained results showed that both methods are suitable for routine analysis of pharmaceutical dosage forms which contain pseudoephedrine, paracetamole and ascorbic acid.Za istovremenu analizu trokomponentne smeÅ”e koja sadrži pseudoefedrin, paracetamol i askorbinsku kiselinu postavljene su dve metode reverzno-fazne teÄne hromatografije pod visokim pritiskom (RP-HPLC). Hromatografski sistem Hewlett Packard 1100 koji Äini HP 1100 binarna pumpa, HP 1100 UV-VIS detektor i HP ChemStation za automatsku obradu podataka koriÅ”Äen je za hromatografsko razdvajanje. Postupak je obuhvatio definisanje hromatografskih uslova, validaciju postavljenih metoda, kao i njihovu primenu za ispitivanje sadržaja pseudoefedrina, paracetamola i askorbinske kiseline u peroralnom praÅ”ku. Optimalna separacija postignuta je u koloni Platinium Alltech Amino 150 mm x 4,6 mm, 5 mm veliÄine Äestica, na temperaturi kolone od 30Ā°C. Volumen injektovanja bio je 20 mL. Mobilna faza u metodi I bila je smeÅ”a metanol-voda (30:70 V/V), pH vrednost podeÅ”ena na 2,5, a u metodi II smeÅ”a metanol-voda (60:40 V/V), pH vrednost podeÅ”ena na 2,9. pH mobilne faze je podeÅ”avan sa 85%-tnom orto-fosfornom kiselinom. Talasna dužina detekcije bila je 214 nm u metodi I i 257 nm u metodi II. Protok mobilne faze za obe metode bio je 1 mL min-1. Postavljene metode su validirane i na osnovu dobijenih parametara procenjeno je da obe predložene metode mogu da se primene za analizu peroralnog praÅ”ka koji sadrži paracetamol, pseudoefedrin i askorbinsku kiselinu
Analitika hidrokortizon-acetata u mastima za oÄi primenom reverzno-fazne teÄne hromatografije pod visokim pritiskom
In this paper the reversed-phase high performance liquid chromatographic method (RP-HPLC) was applied for the determination of hydrocortisone acetate in eye ointment. Analysis were performed on the chromatographic system Hewlett Packard 1100 which consisted of a HP 1100 pump, HP 1100 UV-VIS Detector and HP ChemStation integrator. Separations were performed on a Bio-Sil C18 250 mm x 4,6 mm, 5Āµm particle size column at 30.5 Ā°C. The samples were introduced through a Rheodyne injector valve with a 20 ĀµL sample loop. Methanol - water (75:25 V/V) was used as a mobile phase, at flow rate 1.15 mL/min and pH was adjusted to 4.0 with ortophosphoric acid. UV detection was performed at 254 nm. Mometasone furoate was used as an internal standard. Developed RP-HPLC method was validated and all the validation parameters of the method are given. The proposed method is rapid, accurate, selective and because of its sensitivity and reproducibility, it may be used in routine control of pharmaceutical dosage forms which contain hydrocortisone acetate.Postavljena je metoda reverzno-fazne teÄne hromatografije pod visokim pritiskom (RP-HPLC) za analizu hidrokortizon-acetata u mastima za oÄi. Analiza je izvrÅ”ena na hromatografskom sistemu Hewlett Packard 1100 koji Äine HP 1100 binarna pumpa, HP 1100 UV-VIS detektor i HP ChemStation za automatsku obradu podataka. Postupak je obuhvatio izbor odgovarajuÄih hromatografskih uslova, izbor pogodnog postupka ekstrakcije hidrokortizon-acetata iz masti, kao i validaciju metode. Za hromatografsku analizu odabrana je kolona Bio-Sil C18 250 mm x 4,6 mm, 5Āµm veliÄine Äestica, termostatirana na 30,5Ā°C. Volumen injiciranja bio je 20 ĀµL. Mobilnu fazu Äinila je smeÅ”a metanol?voda (75 : 25 V/V) Äiji je pH podeÅ”en na 4,0 sa 85%-tnom ortofosfatnom kiselinom. Protok mobilne faze bio je 1,15 ml/min., a talasna dužina detekcije 254 nm. Kao interni standard koriÅ”Äen je mometazon-furoat. Postavljena RP-HPLC metoda je validirana, tj. ispitana je robusnost, selektivnost, linearnost, taÄnost, preciznost - ponovljivost i odreÄeni su limit detekcije i limit kvantifikacije. Kako je predložena metoda pouzdana i robusna može se koristiti u rutinskoj analizi doziranih oblika koji sadrže hidrokortizon-acetat
Razvoj hromatografskih metoda za analizu sulfametoksazola, trimetoprima, njihovih degradacionih proizvoda i konzervanasa u sirupu
In this paper the experimental conditions for optimal reversed-phase liquid chromatographic (RP-HPLC) determination of sulfamethoxazole, trimethoprim and preservatives, as well as degradation products of sulfamethoxazole and trimethoprim in syrup were defined. The determination of active compounds and preservatives was carried out on Zorbax Eclipse XDB-C18, 150 mm Ć 4.6 mm, 5 Ī¼m particle size column, mobile phase flow rate was 1.5 mL min-1, and detection at 235 nm for the active compounds and 254 nm for preservatives. Mobile phase A consisted of 150 mL of acetonitrile, 850 mL of water and 1 mL of triethanolamine (pH 5.90 adjusted with diluted acetic acid), while mobile phase B was acetonitrile. The mobile phase ratio was defined by the gradient program. For the determination of degradation products Zorbax Eclipse Plus C18, 100 mm x 4.6 mm, 3.5 Ī¼m particle size column was used, the mobile phase flow rate was 0.5 mL min-1 and detection at 210 nm for 3,4,5-trimethoxybenzoic acid and 254 nm for sulfanilic acid and sulfanilamide. Mobile phase A was 50 mM potassium dihydrogenphosphate (pH 5.60 adjusted with a 0.5 mol L-1 potassium hydroxide), while mobile phase B was acetonitrile. The mobile phase ratio was defined by the gradient program. Through the validation of the developed methods their efficiency and reliability is confirmed and consequently the adequacy for the routine control.U ovom radu prikazano je definisanje eksperimentalnih uslova i optimizacija metoda reverzno-fazne teÄne hromatografije (RP-HPLC) za odreÄivanje sulfametoksazola, trimetoprima i konzervanasa, odnosno degradacionih proizvoda sulfametoksazola i trimetoprima u sirupu. OdreÄivanje sadržaja aktivnih komponenti i konzervanasa vrÅ”eno je na koloni Zorbax Eclipse XDB-C18, 150 mm Ć 4,6 mm, 5 Ī¼m veliÄine Äestica, protok mobilne faze bio je 1,5 mL min-1, dok je detekcija vrÅ”ena na 235 nm za aktivne komponente i 254 nm za konzervanse. Mobilna faza A sastojala se od smeÅ”e 150 mL acetonitrila, 850 mL vode i 1 mL trietanolamina (pH 5,9 podeÅ”en razblaženom sirÄetnom kiselinom), a kao mobilna faza B koriÅ”Äen je acetonitril. Odnos mobilnih faza tokom analize definisan je programom gradijenta. OdreÄivanje sadržaja degradacionih proizvoda vrÅ”eno je na koloni Zorbax Eclipse Plus-C18, 100 mm Ć 4,6 mm, 3,5 Ī¼m veliÄine Äestica, uz protok mobilne faze od 0,5 mL min-1 i detekciju na 210 nm za 3,4,5-trimetoksibenzojevu kiselinu i 254 nm za sulfanilnu kiselinu i sulfanilamid. Mobilna faza A bila je 50 mM kalijum-dihidrogenfosfat (pH 5,60 podeÅ”en sa 0,5 mol L-1 kalijum-hidroksidom), a mobilna faza B bio je acetonitril. Odnos mobilnih faza tokom analize definisan je programom gradijenta. Validacijom postavljenih metoda potvrÄeno je da su efikasne i pouzdane, i kao takve pogodne za rutinsku kontrolu
Teachersā views of inclusive education in Serbian schools
This study was conducted to determine the attitudes of teachers concerning inclusion in schools all over Serbia. The respondents were teachers of different subjects who were tasked to anonymously complete the provided closed-type questionnaire (970 respondents). Primary and secondary school teachers from urban and rural areas of the Republic of Serbia participated in the research. The results indicate that the teachers are supportive of inclusion. Despite significant differences in respondentsā answers, the results of the research show that there are many similarities in teacher responses toward inclusive education. The results show that it is still necessary to work on the implementation of inclusive education in Serbia, especially to educate the teaching staff and involve experts in the planning and development of individual educational plans.Keywords: attitudes; inclusive education; Serbia; teacher
Central Composite Design with/without Artificial Neural Networks in Microemulsion Liquid Chromatography Separation Robustness Testing
In past few years, for overcoming some analytical problems in liquid chromatography, the microemulsion as eluent was employed. Due to the strict regulatory requirements, robustness testing became important especially when proposing completely new method such as microemulsion liquid chromatography (MELC). In this paper robustness testing of MELC method, proposed for carbamazepine and its impurities (iminostilben and iminodibenzyl) separation, was done using two different approaches both based on experiments defined using central composite design (CCD). Input and output data from CCD were either handled as second order polynomials and tested with Analysis of variance (ANOVA), or as variables in Artificial Neural Networks (ANN). From both approaches appropriate conclusions about system robustness were distinguished, e. g. that the influence of surfactant content on chromatographic retention was the largest for all analytes, meaning that small changes in its concentration will strongly influenced on chromatographic retention. On the other hand influence of the pH of the mobile phase proved to be negligible, meaning that the substances are mainly distributed in the interfacial layer. ANN gave better results and proved to be better tool for explanation and understanding of investigated factors effects on the chromatographic system and for definition of the robustness limits
Pharmacy students' perspectives on online lectures during the COVID ā 19 pandemic ā case study from the University of Belgrade.
Synchronous lectures tend to be used as the prevalent
method of online instruction, irrespective of notable differences
and obvious limitations when compared to their in-person delivery.
Study aim was to assess studentsā perspective on online lectures
held during the emergency remote teaching (ERT) due to COVID-19
pandemic.
Method: Students were invited to take part in online survey related
to their experience with ERT. Survey included 25 items related to:
satisfaction (14 items), motivation (3 items), interaction with peers
and lecturers (4 items), and perceived challenges (4 items). A 5-point
Likert scale was employed. Statistical analysis was performed using
the SPSS software.
Results: A total of 387 students participated in the survey. Majority
of respondents (79.3%) were junior students. Among them, 72.6%
reported no previous experience with online learning. Although
relatively high level of satisfaction was reported (mean score
3.91Ā±0.75), challenges were also scored relatively high (3.05Ā±0.99),
while interaction was scored somewhat lower (2.98Ā±0.73), and the
least mean score was observed for motivation (2.73Ā±0.58). Students
reported having trouble to keep motivation, concentration and
focus during online lectures, which usually took long hours per day.
Interaction with peers was reported as unsatisfactory (2.48Ā±1.46),
whereas it was more feasible with lecturers (3.24Ā±1.42). Students
were quite satisfied with the possibility to organize their time flexibly
(71.4%), and with respect to the workload (54.5%), while they were
less convinced that online sessions provide enough opportunities
to reflect on what has been learnt (50,1% agree, 25,1% neither
agree nor disagree).
Conclusions: The results obtained indicate that students are
somewhat hesitant with respect to online lectures as the main mode
of instruction. Lectures, generally, place students in a passive role,
which is further increased in online delivery. In order to support
studentsā engagement and success, online lectures should be
combined with more active instructional strategies.ORAL PREVIEW (usmena prezentacija)Link to the Pharmacy Education version [https://farfar.pharmacy.bg.ac.rs/handle/123456789/4381
Computer-assisted optimization and validation of LC analysis of trimetazidine dihydrochloride and its impurities
Modeling the Geography Class through Problem-Based Teaching: a Case Study from Novi Sad, Serbia
The idea of problem-based teaching, i.e. learning through solving problems, is not a new one, but has been fairly neglected in the teaching process. The aim of this research is to consider the possibility of applying this learning model in teaching geography in primary and grammar schools. This teaching model was proposed for the presentation of the teaching unit Australia and Oceania, in the framework of the thematic unit Political/Geographic, Demographic and Economic/Geographic Features of Certain Parts of the World. The model implies group work. The expected successful outcome of the applied teaching model has been verified by the results of a survey and the scores achieved in the knowledge test. The study contains the entire course of the experimental teaching of the unit Australia and Oceania by applying problem-based teaching, and presents and analyzes the results achieved. The classes were modelled by relying on Hill-Slaterā²s model. A t-test was used for the statistical analysis of data in order to test the hypothesis on differences in the arithmetic mean. The choice and application of the statistical mathematical procedure are determined by the nature of the phenomenon which is the subject of this research. The software packages Mathematica and Excel were used in order to statistically analyze data and to draw tables and graphs
Evaluation of Seven Chromatographic Response Functions on Simulated and Experimentally Obtained Chromatograms in Hydrophilic Interaction Liquid Chromatography System
This paper investigates the ability of seven chromatographic response functions to measure the quality of chromatograms obtained in hydrophilic interaction liquid chromatography (HILIC). First, the functions were tested on a set of simulated chromatograms and differences in their mathematical design were discussed. Second, the functions were evaluated on the experimentally obtained chromatograms in HILIC analysis of model mixture consisted of beta agonists and antagonists. The ranking of chromatograms obtained by different functions was significantly different, implying that the accuracy of the optimization procedure is strongly dependent on the function that was selected as an output. Investigation of potential drawbacks of each function was conducted and general recommendations concerning the use of chromatographic response functions in optimization strategies are proposed.This is peer-reviewed version of the following article: RakiÄ, T.; StojanoviÄ, B. J.; JovanoviÄ, M.; MalenoviÄ, A.; IvanoviÄ, D.; Medenica, M. Evaluation of Seven Chromatographic Response Functions on Simulated and Experimentally Obtained Chromatograms in Hydrophilic Interaction Liquid Chromatography System. Anal. Lett. 2013, 46 (8), 1198ā1212. [https://doi.org/10.1080/00032719.2012.755689
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