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Use of micellar electrokinetic chromatogramy for the assay of degradation products of the pharmaceutical compounds
Vančura, Luboš ; Pospíšilová, Marie (advisor) ; Polášek, Miroslav (referee)
Use of micellar electrokinetic chromatography for the determination of pharmaceutical impurities A new method of micellar electrokinetic chromatography (MEKC) for the separation and selective determination of clotrimazole and its degradation product (2- chlorophenyl)diphenylmethanol in pharmaceutical preparations was developed and validated. The analysis was carried out in a fused-silica capillary (internal diameter 75 µm, total length 60 cm, effective length 50 cm) with UV detection at 210 nm, voltage 30 kV, hydrodynamic sample injection at 34.5 mbar for 7 s and temperature 25 o C. The optimum background electrolyte consisted of 15 mM potassium dihydrogen phosphate, 20 mM sodium dodecyl sulphate, 30 mM sodium cholate and 10 mM β-cyclodextrin (pH = 8.2); sodium diclophenac was used as internal standard. The separation took less than 12 min.
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Determination of pefloxacin by the technique of sequential injection analysis with chemiluminescence detection
Šimura, Jan ; Polášek, Miroslav (advisor) ; Sklenářová, Hana (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Consultant: doc. RNDr. Miroslav Polášek, CSc. Diploma Thesis Title: Determination of pefloxacin mesylate dihydrate using sequential injection analysis with chemiluminescent detection A simple and rapid method for determination of pefloxacin mesylate dihydrate (PEF) using sequential injection analysis with chemiluminescent detection was devised and optimised. Chemiluminescent reaction was based on redox reaction of tris(2,2′- bipyridine)dichlororuthenium(II) hexahydrate. Ammonium cerium(IV) sulfate was used as an oxidant. Sodium acetate was used as a third component which had enhancing effect on CL reaction. The calibration curve was linear in the range 5,2* 10-07 - 1,29* 10-05 M of PEF, R2= 0,9948. The limit of detection (LOD) was 0,21 μM and the limit of quantification (LOQ) was 0,28 μM. This optimised method was used for the determination of PEF in ABAKTAL inj. sol. Interferences from some excipients (EDTA, ascorbic acid and sodium metabisulfite) used in the production of injection solutions were examined.
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Vývoj elektrochemického glutamátového biosenzoru
Doležalová, Julie ; Solich, Petr (advisor) ; Polášek, Miroslav (referee)
DEVELOPMENT OF A GLUTAMATE ELECTROCHEMICAL BIOSENSOR Julie Doležalová (Department of Analytical Chemistry, Faculty of Pharmacy, Charles University in Prague) In cooperation with: Sofia A.L.P. Gomes, Alberto N. Araújo (Department of Physical Chemistry, Faculty of Pharmacy, University of Porto) L-Glutamic acid and monosodium glutamate are used to enhance flavour in food prepared at home, restaurants, and by the food processing industry [1]. Glutamate also plays an important role in many metabolic processes. Nevertheless its use is being kept under certain limits as some people have experienced adverse effects, such as stiffness and tension, after its ingestion. Moreover, some studies demonstrate its connection with the appearance of neurological manifestations, such as Parkinson's and Alzheimer's disease. The determination of L-glutamic acid is therefore of major importance. In this work a novel L-glutamate biosensor was developed using a dehydrogenase enzyme (L-glutamate dehydrogenase). These redox enzyme requires for its activity nicotinamide (NAD(P)+ /NAD(P)H) coenzyme, which reduced form was electrochemically regenerated by the water-soluble dye, methylene green. Graphite electrodes were modified with a poly(methylene green) thin film by means of methylene green electrochemical polymerization...
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Vývoj umělého zubu založený na technice povrchové plasmové resonance
Solanská, Kateřina ; Solich, Petr (advisor) ; Polášek, Miroslav (referee)
For development an artificial tooth hydroxyapatite nanoparticles solution was electrophoretically deposited on the gold chip. It was established that experimental conditions of solution preparation, electrically field have marked effect to thickness of the hydroxyapatite layer. By this way was prepared chip suitable for SPR measurements. In the firs step the bovine serum albumin (BSA) was chosen as the model protein shows absorption on the hydroxyapatite layer. Further the native saliva and artificial saliva were used for pellicle forming. Samples of saliva showed difference between binding behaviors on the hydroxyapatite layer. The application of chlorhexidingluconate pharmaceuticals on the pellicle shows increase in thickness but rinsing with native saliva disclosed that the components of chlorhexidingluconate pharmaceuticals can be easily removed from the surface.
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Determination of glucosamine by capillary zone electrophoresis with contactless conductivity detection
Los, Petr ; Polášek, Miroslav (advisor) ; Pospíšilová, Marie (referee)
7.1.2. Determination of glucosamine using capillary zone electrophoresis with conductivity contactless detection A novel CE method with contactless conductivity detection suitable for the determination of glucosamine and K+ in pharmaceuticals was devised. Under the optimum conditions (aqueous 30 mM acetate buffer of pH 5.2 as the background electrolyte; voltage 30 kV; 25 řC) glucosamine (migrating as glucosaminium cation) was well separated from K+ that could occur in the dosage forms as excipient. The CE analysis was performed in fused-silica capillaries (50 μm i.d., 75 cm total length, 27 cm to detector) and the separation took < 3 min. The calibration graphs were linear for both glucosamine (100 - 300 μg/ml; rš = 0.997) and K+ (15 - 75 μg/ml; rš = 0.997) when using ethanolamine (100 μg/ml) as the internal standard. The LOD values (S/N = 3) were 9.3 μg/ml for glucosamine and 2.9 μg/ml for K+. The method was applied to the assay of glucosamine content in various dosage forms. Intermediate precision evaluated by determining the content of glucosamine in a single formulation on 3 consecutive days was characterized by RSD 2.35% (n=15). Acceptable accuracy of the CE method was confirmed by the added/found glucosamine recovery experiments (recoveries 94.6-103.3%) and by statistical comparison of the results...
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Assay of Glucosamine in Pharmaceuticals and Nutraceuticals by Capillary Isotachophoresis
Elsnerová, Lenka ; Pospíšilová, Marie (advisor) ; Polášek, Miroslav (referee)
Capillary isotachophoresis (ITP) with conductivity detection has been used for separating and determining of glucosamine (GA) from the SYSADOA group (symptomatic slow acting drugs of osteoarthritis). The optimised ITP electrolyte system consisted of 10 mM potassium picolinate and 10 mM picolinic acid (pH 5.4) as the leading electrolyte (LE) and 10 mM formic acid (pH 3.0) as the terninating elektrolyte (TE). The driving and the detection curents were 50 µA (for 340 s) and 10 µA, respectively. A single analysis took ˂ 10 min. Under the optimum conditions the effective mobility of GA was determined as 24,7 x 10-9 m2 .V- ¹s- ¹ when using tetraethylamonium-iodide as the standard of the mobility. The calibration graph was rectilinear in the range 50 - 200 mg.l-1 of GA with r2 = 0,99747. The RSD was 0,52 % (n=6) when determining 100 mg.l-1 of GA. The ITP method was applied to the assay of GA content in various pharmaceuticals and nutraceuticals. Acceptable accuracy of the method was confirmed by the added/found GA recovery experiments (recoveries from 96.2-100.3%).
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Potenciometrické stanovení gentamycinu ve farmaceutických přípravcích
Kočí, Martina ; Pospíšilová, Marie (advisor) ; Polášek, Miroslav (referee)
Gentamicin is an aminoglycoside antibiotic, and can treat many types of bacterial infections, particularly Gram-negative infection. It is one of the heat-stable antibiotics that remain active after autoclaving, which make it particularly useful in the preparation in the certain microbiological growth media. Traditionally, pharmaceutical analysis of these compounds relies heavily on chromatography, yet also frequently requiring the use of reagent-based detection principles like spectrophotometric, chemiluminescent detection in flow-injection analysis , capillary electrophoresis, a novel LC/ELSD, thin-layer chromatography, HPLC.A simple and sensitive potentiometric procedure for the determination of gentamicin is presented, after development of selective electrodes based on PVC membranes using different type of cyclodextrins and its derivatives, or Evans Blue complex with gentamicin as ionophers. Several mediator solvents and lipophilic ionic species were also used in order to optimize the characteristics of the membranes. The evaluation of the general characteristics for all the units prepared revealed an analytical linear range of about 2x10-4; 5x10-3 mol L-1, slopes of about 50 mV/dec, good reproducibility and low response times. The evaluation of Potentiometric selectivity coefficients will permit to...
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