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The significance of magnesium for human health
Škeřík, Jan ; Hrstka, Miroslav (referee) ; Vránová, Dana (advisor)
Aim of this bachelor thesis was to compare different forms of magnesium. The characteristics and history of magnesium was briefly described at the beginning of the theoretical part. The following chapters explain the importance of magnesium in the body, hypomagnesemia, hypermagnesemia. Another section describes magnesium effect on various diseases, increased intake of magnesium and magnesium metabolism. The ninth and tenth chapter describes the effects of nicotine and alcohol on the metabolism of magnesium and magnesium content in drinking and mineral water. Conclusion of the theoretical part is dedicated to the description of the analytical methods of dosage forms. At the heart of the practical part was using several commonly used methods to determine best magnesium addition. It was the method of determination of the mass uniformity, determining magnesium contents in the tablet, the determination of disintegration, dissolution determination and hardness determination.
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Humic substances as transport medium for plant nutrition
Vlková, Markéta ; Solná, Irena (referee) ; Klučáková, Martina (advisor)
This bachelor thesis treats about humic matters and their application in agriculture by means of hydrogels transport medium. It studies progressive releasing of substances, which could be used as more common nutrition for plants, prepared from superabsorbent polymers. Research was implemented in collaboration with industrial partners. The substances are synthetically made of sodium Lignohumate and mixture of industrial fertilizer called NPK. Released substances were characterized by using some methods. First, there were measured qualities, which didn’t specify released compounds, like swelling, conductivity, pH and absorption of hydrogels with different wavelengths. More details came with methods ICP-OES and ion chromatography. Hydrogels which contained both mixtures of matters written up, were studied in water solution for 5 weeks and every week all characterization were measured. From the results we can see that both of the mixtures decrease ability of hydrogel’s swelling, mainly NPK. Measuring of absorption showed that the most of the substances released from sodium Lignohumate were from hydrogels without NPK. By other measuring, we noticed realizing of potassium and phosphorus elements. The most of them were from hydrogels containing NPK. By measuring ion chromatography, we found chloride, phosphoric, sulfuric and nitric ions in solution.
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Hydrogels based on microemulsions and polyelectrolytes
Růžičková, Kristýna ; Kalina, Michal (referee) ; Mravec, Filip (advisor)
This bachelor thesis deals with preparation and characterization of microemulsion based phase separated hydrogels while using low molecular weight and high molecular weight hyaluronan. Microemulsions were prepared from canola oil, sunflower oil, lemon oil and tea tree oil. As a dye for studies of behaviour of hydrogels was used Oil red O which simulates hydrophobic drug. The main part of this thesis studies the release of this dye from hydrogels by using UV-VIS spectroscopy. The content of the dye in hydrogels was monitored after 24, 48 and 72 hours. Based on measured data we can state that hydrogel prepared from low molecular weight hyaluronan release bigger amount of the dye than hydrogel from high molecular weight hyaluronan. Based on measured data after 72 hours we can say that hydrogel from microemulsion with tea tree oil and hydrogel from microemulsion with lemon oil released bigger amount of the dye than hydrogel without microemulsion. Another advantage of these two hydrogels is increased thougness. Content of sunflower and canola oil indicated rather negative influence on behaviour of hydrogels.
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Transport properties of dextran-based hydrogel systems
Vyroubal, David ; Kalina, Michal (referee) ; Klučáková, Martina (advisor)
This bachelor thesis is focused on study of transport properties of dextran-based hydrogel systems. The aim of this work is to determine their ability to absorb and release substances. Nile red was used as a probe to examine the transport properties of these systems. All hydrogels were prepared by the so-called wet way. At first stock solutions of dextran and surfactants were prepared and subsequently mixed to form a hydrogel. Nile red was dissolved in the surfactant stock solution and colored gels were formed upon mixing with dextran stock solution. Several types of gels were thus formed which differ in the concentration of the surfactant and nile red used. Supernatants were spectrophotometrically measured at various time intervals. For study of transport properties in multiple surroundings, the original supernatant was replaced after hydrogel preparation with a surfactant solution or physiological saline solution.
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Superabsorbents with controlled release of nutrients
Závodská, Petra ; Kratochvílová, Romana (referee) ; Klučáková, Martina (advisor)
This thesis is focused on the study of superabsorbent polymers and their ability of control release of nutrients. These polymers can absorb huge amount of water, up to hundredth times more than the original weight is. In combination with nutrients, especially nitrogen, phosphorus, potassium and lignohumate, they make effective fertilizer. Due to this fact, the possibility of use in agriculture is increasing. Therefore, experiments that are researching the ability of containing the water were performed, the swelling capacity was measured. Experiments that are related to control release of nutrients were performed next. Therefore, this thesis is focused on the study of superabsorbent polymer characterisation, that can be used in agriculture.
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Releasing of the solubilized substances from the phase-separated hydrogels
Havlíková, Martina ; Krouská, Jitka (referee) ; Mravec, Filip (advisor)
This bachelor thesis is focused on releasing of the solubilized substances from the phase separeted hydrogels. The aim of this work is to determine the solubilization capacity of these hydrogels. Preparation of them were based on interaction between hyaluronan and cationic surfactant carbethopendecinium bromide. Hydrogels were prepared by two possible ways, „wet“ and „dry way“. For solubilization experiments were used fluorescein and acridine orange as fluorescent probes. Primarily UV-VIS spectrophotometry was used to determine if these probes are released form hydrogel or not. Hydrogels were monitored after 24, 48 and 72 hours from their preparation. But this method proved to be inappropriate and inaccurate, because of cloudy supernatants over the hydrogels and also because of very low concentrations of fluorescent probe in this solution. For these reasons instead of this metod was used method, which is based on fluorescence. The instrument is called MicroTime 200. It´s very accurate method and results of this are considered like relevant. It was proved that fluorescein as a negatively charged molecule is released less than acridine orange.
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Study of influence of hydrophilic carriers on the solubility of a poorly soluble drug
Veselá, Eliška ; Šklubalová, Zdeňka (advisor) ; Vraníková, Barbora (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of: Department of Pharmaceutical Technology Supervisor: Doc. PharmDr. Zdeňka Šklubalová, Ph.D. Consultant: Mgr. Jana Brokešová Student: Eliška Veselá Title of Thesis: Study of influence of hydrophilic carriers on the solubility of a poorly soluble drug The aim of this thesis was to enhance the solubility of a poorly soluble model drug meloxicam (MLX) by preparing binary interactive mixtures with hydrophilic carriers by simple mixing and co-milling. The mixtures were characterized for granulometric properties. The dissolution studies were carried out using the USP-4 apparatus assembled with a flow-through powder cell in an open-loop system. The dissolution rate rrel (min-1 ) and the amount of released drug mrel (%) were evaluated. The observable positive effect of carriers was registerred in terms of increasing the dissolution rate and the amount of released drug for both mixed and co-milled mixtures comparing to the raw drug. Mixtures with hypromellose were the exception; the improvement of the monitored parameters was not detected.
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Study of influence of hydrophilic carriers on the solubility of a poorly soluble drug
Veselá, Eliška ; Šklubalová, Zdeňka (advisor) ; Vraníková, Barbora (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of: Department of Pharmaceutical Technology Supervisor: Doc. PharmDr. Zdeňka Šklubalová, Ph.D. Consultant: Mgr. Jana Brokešová Student: Eliška Veselá Title of Thesis: Study of influence of hydrophilic carriers on the solubility of a poorly soluble drug The aim of this thesis was to enhance the solubility of a poorly soluble model drug meloxicam (MLX) by preparing binary interactive mixtures with hydrophilic carriers by simple mixing and co-milling. The mixtures were characterized for granulometric properties. The dissolution studies were carried out using the USP-4 apparatus assembled with a flow-through powder cell in an open-loop system. The dissolution rate rrel (min-1 ) and the amount of released drug mrel (%) were evaluated. The observable positive effect of carriers was registerred in terms of increasing the dissolution rate and the amount of released drug for both mixed and co-milled mixtures comparing to the raw drug. Mixtures with hypromellose were the exception; the improvement of the monitored parameters was not detected.
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Multidimensional characterization of polyelectrolytes and interpolyelectrolyte complexes in aqueous solutions
Murmiliuk, Anastasiia ; Štěpánek, Miroslav (advisor) ; Šachl, Radek (referee) ; Hoffmann, Ingo (referee)
Multidimensional characterization of polyelectrolytes and interpolyelectrolyte complexes in aqueous solutions Abstract: This PhD thesis is dedicated to the study of polyelectrolytes and their self-assembly in aqueous solutions. The morphology and ionization state of individual polymer chains were investigated as well as their co-assembly with oppositely charged species. First, the charge regulation of short and long weak polyelectrolytes in aqueous solution was investigated to deeper understand their pH-responsive properties. The changes of ionization degree and charge of oligopeptides composed of 5 amino acids with acid side-chains and 5 with basic side chains were followed upon varying the pH in order to reveal the effect of interactions between the like-charged and oppositely charged groups. It was shown that intra-molecular electrostatic interactions and conformational flexibility caused the suppression of the total charge and enhancement of ionization of the peptides. To get an insight into the distribution of local H+ concentration in the proximity of a polyelectrolyte chain, a modified polyelectrolyte structure was used with a fluorescent pH- indicator, covalently attached at the end of the chain. Ionization of the pH-responsive fluorophore revealed its effective pK which was compared with the local...
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Multidimensional characterization of polyelectrolytes and interpolyelectrolyte complexes in aqueous solutions
Murmiliuk, Anastasiia ; Štěpánek, Miroslav (advisor) ; Šachl, Radek (referee) ; Hoffmann, Ingo (referee)
Multidimensional characterization of polyelectrolytes and interpolyelectrolyte complexes in aqueous solutions Abstract: This PhD thesis is dedicated to the study of polyelectrolytes and their self-assembly in aqueous solutions. The morphology and ionization state of individual polymer chains were investigated as well as their co-assembly with oppositely charged species. First, the charge regulation of short and long weak polyelectrolytes in aqueous solution was investigated to deeper understand their pH-responsive properties. The changes of ionization degree and charge of oligopeptides composed of 5 amino acids with acid side-chains and 5 with basic side chains were followed upon varying the pH in order to reveal the effect of interactions between the like-charged and oppositely charged groups. It was shown that intra-molecular electrostatic interactions and conformational flexibility caused the suppression of the total charge and enhancement of ionization of the peptides. To get an insight into the distribution of local H+ concentration in the proximity of a polyelectrolyte chain, a modified polyelectrolyte structure was used with a fluorescent pH- indicator, covalently attached at the end of the chain. Ionization of the pH-responsive fluorophore revealed its effective pK which was compared with the local...
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