|
|
Controlled Drug Release from Biodegradable Hydrogels.
Oborná, Jana ; Chýlková, Jaromíra (referee) ; Kráčmar, Stanislav (referee) ; Kučerík, Jiří (referee) ; Vávrová, Milada (advisor)
This dissertation is focused on the controlled release of drugs from a biodegradable amphiphilic hydrogel based on hydrophobic poly(lactic acid), poly(glycolic acid) and hydrophilic poly(ethylene glycol) (PLGA-PEG-PLGA, ABA) and its modification with itaconic anhydride (ITA). The resulting ,-itaconyl(PLGA-PEG-PLGA) copolymer is referred to as ITA/PLGA-PEG-PLGA/ITA or ITA/ABA/ITA. Itaconic acid provides reactive double bonds and a functional carboxyl group at the ends of the PLGA-PEG-PLGA copolymer chain, thereby rendering the modified ITA/ABA/ITA copolymer less hydrophobic and offering the possibility of forming a carrier for hydrophilic drug substances. These functional copolymers are thermosensitive and change in the external environment (e.g. temperature) causes a sol-gel phase transition due to the formation of micellar structure. The bioactive substances can thus be mixed with a copolymer which is in a low viscous phase (sol phase) and subsequently the mixture can be injected into patient's body at the target site where it forms a gel at 37 °C. This hydrogel becomes a drug depot, which gradually releases the active substance. Prediction of the substance’s release profile from the hydrogel is an effective tool to determine the frequency of administration, potentially enhancing efficacy, and assessment of side effects associated with dosing. The analgesic paracetamol and the sulfonamide antibiotic sulfathiazole were used as model drugs, representing hydrophilic and hydrophobic substances, respectively. The active substances had a significant effect on the resulting hydrogel stiffness. Type of solvent, incubation medium and nanohydroxyapatite also influenced on the gel stiffness and subsequent stability of the hydrogel-drug system. Controlled release of drugs took place in simulated conditions of the human body. Verification of Korsmeyer-Peppas (KP) drug-release model is also discussed in this thesis. The KP model was found suitable for simulating the release of sulfathiazole from ABA and ITA/ABA/ITA hydrogels. On the contrary, the performance of KP model was not suitable for describing the release of paracetamol from the ABA hydrogels. Therefore, a new regression model suitable for both buffered simulated media and water has been proposed. The proposed model fitted better the release of both sulfathiazole and paracetamol from composite material prepared from ABA hydrogel and nanohydroxyapatite.
|
|
|
Selected drugs in drinking water sources and possibilities of their removal by adsorption
Lukášová, Daniela ; Ilavský,, Ján (referee) ; Kyncl, Miroslav (referee) ; Biela, Renata (advisor)
The dissertation deals with the occurrence of a selected group of drugs in drinking water sources and their subsequent removal. The work presents information on the occurrence of pharmaceuticals in the environment, their consumption in recent years and their division into different groups. Various options for waterworks processes that remove drugs from water are also described. For the experimental part of the dissertation, adsorption on selected sorption materials was chosen as the removal process. The removal of drugs from water was carried out in two ways, a static and a dynamic test. At the end of the work, the efficiency of sorption materials and other parameters related to adsorption are evaluated.
|
|
|
Interactions of pharmaceuticals with humic acids
Libiger, Jan ; Enev, Vojtěch (referee) ; Klučáková, Martina (advisor)
The bachelor thesis is focused on interaction of drugs with humic substances, which are part of organic soil matter. The results would help in understanding the behavior of drugs in soil and other natural systems. Three drugs were selected. Humic acid was selected as a sorbent, which was extracted from lignin, the lower one is assumed to be the same as that in organic soil. Based on a comparison of the measurement results using the UV-VIS method, it was determined how much the acid of the given drug is able to absorb and how much it is released back into the water. The theoretical part deals with the information about soil organic matter, with the information about humic substances, with the information about drugs such as ibuprofen, sulfamethoxazol or sulfapyridine. Furthermore, the theoretical part deals with methods of analysis.
|
|
|
Micropollutants in water resources and ways of their elimination
Lukášová, Daniela ; Látal,, Milan (referee) ; Biela, Renata (advisor)
The diploma thesis deals with micro-fuels in drinking water sources and their subsequent removal. In the thesis mainly pesticides and pharmaceuticals are described. The reader is first introduced to the most common pesticides occurring in water and their consumption. Drugs are described in a similar context. In addition, there are practical studies on the occurrence, degradation and removal of micro-pollutants from water. The final thesis is a laboratory experiment dealing with the removal of salicylic acid from water by filtration through the filtration material Bayoxide E33 and activated carbon. The thesis describes the procedure and results of the experiment.
|
|
|
Monitoring the effectiveness of selected adsorbents to remove micropollutants from drinking water
Kabelíková, Eva ; Svoboda,, Miroslav (referee) ; Biela, Renata (advisor)
This diploma thesis deals with the effectiveness of selected adsorbents for the removal of micropollutants from drinking water. In the first part there are described individual types of micropollutants and their occurrence in water. Further, there are described pharmaceuticals and their consumption in the world. At the end of the first part, the possibilities of removing micropollutants in drinking water treatment are approached and two water treatment plants in the Czech Republic have been selected, which already use the technology of the removal of some micropollutants. In the practical part of this diploma thesis is performed an experiment of removal of Ibuprofen from model water by adsorption on selected materials, which are Filtrasorb F100, Bayoxide E33 and GEH.
|
|
|
Embedded Control Unit for Instrumentation of Laboratory Appliance
Voda, Zbyšek ; Strnadel, Josef (referee) ; Šimek, Václav (advisor)
Aim of this thesis is modular design of control system for Golem device, which is used for drug research. Several modules with specified controlled area were designed. They communicate using CAN bus and are controlled by Raspberry Pi computer. The thesis includes PCB design and control firmware for modules, backend application for Raspberry Pi, which provides application interface, and simple protocol used for communication between modules. Designed system was tested in simulated environment.
|
|
|
Use of Capillary Zone Electrophoresis for Determination of Selected Analgetics in Water
Čapka, Lukáš ; Opatřilová, Radka (referee) ; Márová, Ivana (referee) ; Vávrová, Milada (advisor)
From viewpoint of environmental analysis in the whole world became popular in the latest years the question of drugs’ breakthrough to the component of environment. These contami-nants belong to the biological active compounds, with different physical-chemical and biolog-ical properties and evince great tendency to bioaccumulation. They penetrate to the environ-ment because of their increasing of usage and wrong techniques of liquidation. The most often use drugs are preparations against pain – analgetics, and from this category there are non-steroidal anti-inflammatory drugs. The frequent usage of this compounds relate to their easy accessibility. From this large group of compounds was chosen for monitoring: diclofenac, ibuprofen, ketoprofen, salicylic acid, naproxen and acetaminophen; because they include in favorite preparations. The monitoring matrix was the wastewater from two waste water treat-ment plants (WWTP). The sampling was performed in inflow and outflow because the com-paring of concentration of selected contaminants and discovering of efficiency of removing the polutants reliance on treatment technology. For extraction of selected contaminants was used solid phase extraction (SPE) and for determination was used capillary zone electrophore-sis (CZE) with diode array detection (DAD). There was identified and quantified all of se-lected analgetics in inflow and so in outflow of WWTP. That means, this polutants infuse into surface water and then into other components of environment.
|
|
|
Pharmaceuticals in drinking water sources and possibility of their removal
Lukášová, Daniela ; Talašová, Lucie (referee) ; Biela, Renata (advisor)
Bachelor thesis deals with drugs in drinking water sources, and possibility of their removal. In the first part of the bachelor thesis describes the sources of pharmaceuticals in surface waters, which can be a source for drinking water. Below are described the concentration of drugs in the water and then the reader is familiar with the most frequently occurring drugs in the waters and their consumption. The second part of the bachelor thesis is devoted to Czech and foreign projects that deal with drugs in the drinking water. The third part describes the options for the removal of water by using various medicines water processes. At the conclusion of the work of the design laboratory experiment is described for removing the drug from the water.
|
|
|
Determination of antibiotics in the soil ecosystem
Brož, Tomáš ; Zlámalová Gargošová, Helena (referee) ; Mravcová, Ludmila (advisor)
This work deals with a current issue of increasing drug concentrations and thus the growing number of resistant bacteria in the soil. One of the problem helping this issue is the fertilization of agricultural fields with animal faeces, in which antibiotics occur in an unchanged and still active form, as well as the insufficient effectiveness of conventional methods used in wastewater treatment plants. In an effort to improve the monitoring of this problem, a method for the determination of these antibacterial agents in the soil matrix, using solid phase extraction, and also a UPLC/MS method for their evaluation have been developed and optimized. From the group of sulfonamide antibiotics, sulfacetamide, sulfadiazole, sulfamerazine, sulfamethazine, sulfamethoxazole, sulfapyridine, sulfasalazine, sulfathiaosal and trimethoprim were selected. The lowest limit of detection for the method is 0.3 µg/g for sulfathiazole and the highest of 8.1 µg/g for sulfasalazine. The highest average yields were achieved with sulfamethoxazole, namely 63 ±8 %.
|
|
|
Aplication of gas chromatography for determination of drug residuals in waters
Lacina, Petr ; Stoupalová, Michaela (referee) ; Vávrová, Milada (advisor)
Diploma thesis is focused on the choose of methods and optimalisation analysis procedure of selected pharmaceuticals (salicylic acid, ibuprofene, naproxene, ketoprofene and diclofenac) in surface and waste water by using gas chromatography with mass spectrometer (GC-MS). Solid-phase extraction (SPE) with Oasis HLB cartridges was used as an extraction method in this analysis. Extraction is followed by derivatization and their optimalization of selected pharmaceuticals. Derivatization and its optimalization were performed by two silylation reagens N-methyl-N-(trimethylsilyl)trifluoroacetamide (MSTFA) and N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA). Different volumes of derivatization reagents, different temperatures and different times were used during the procedure. The best combination is then used for analysis of real samples. Real samples of waste water were collected in sewage treatment plants in Brno – Modřice and real samples of surface water were collected from several rivers and one pond in region Moravia. This thesis also presents and tests SPE methods for extraction and concentration selected sulfonamide residues (sulfamethazine, sulfamethoxazole, sulfapyridine and sulfathiazole) from the aquatic environment.
|
guest ::
