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Properties of fibers based on polyhydroxybutyrate
Štulrajterová, Lujza ; Tocháček, Jiří (referee) ; Přikryl, Radek (advisor)
Táto práca sa zaoberá zvlákňovaním biopolymérov z taveniny. V teoretickej časti sú zhrnuté doterajšie poznatky o zvlákňovaní poly(3-hydroxy butyrátu) (PHB) a poly(mliečnej kyseliny) (PLA). Následne boli zvláknené polymérne zmesi na báze PHB s rôznym zložením, čo umožnilo štúdium vplyvu PLA, zmäkčovadiel a ich množstva na vlastnosti pripravených vlákien. Boli použité tri komerčné zmäkčovadlá (ATBC, PEG, A6) a dva experimentálne syntetizované. Zvláknenie bolo prevedené na troch rôznych zvlákňovacích linkách. Konvenčné zvlákňovacie linky s odťahovými rýchlosťami nad 150 m/min sa preukázali ako nevhodné pre spracovanie našich zmesí. Kvôli nedostatočnej pevnosti taveniny sú potrebné nízke odťahové rýchlosti. Boli pripravené vlákna s dĺžiacim pomerom 6,4; ktoré boli následne analyzované pomocou GPC, MDSC a ťahovej skúšky. Na základe nameraných teplôt skelného prechodu zmäkčovadlá ATBC a PEG vykázali lepšiu schopnosť zmäkčiť skúmané PLA/PHB zmesi. Vlákna obsahujúce A6 vykazovali najvyššiu pevnosť v ťahu (250 MPa) a modul pružnosti (2,7 GPa). Nakoniec bol skúmaný vplyv starnutia, tepla a vriacej vody na mechanické vlastnosti týchto vlákien.
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Utilization of liquefied soils in the form of backfilling self-compacting grouts
Chlachula, Jakub ; Krejčí, Pavel (referee) ; Drochytka, Rostislav (advisor)
The bachelor thesis focuses on the research of liquefied soils based on backfilling self compacting grouts. These grouts could be used as bedding for utility lines with lower cost and without unnecessary waste. The prerequisite is that the soil will be stabilized by a suitable stabilizing admixture, which should increase the strength of the composite. It will be necessary to liquefy this composite by using water and suitable liquefaction or plasticizers. As part of this thesis, currently known and used stabilizing admixture and plasticizers are also evaluated, same as the geological situation in the Czech Republic.
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Softening of poly(3-hydroxybutyrate)
Brňák, Matúš ; Petruš, Josef (referee) ; Kučera, František (advisor)
The bachelor thesis deals with the inluence of PHB softening, of selected types of plasticizers. The effect of the plasticizers are compared between themselves with regard to their properties and structure. The theoretical part summarizes the knowledge about softening polymers and characterized different types of plasticizers. The experimental part deals with PHB softening in the solution and in the melt. The plasticizers ATBC, TBC, ATEC, TEC, TOTM, PVAc and butylglycolate dilution containing 30 wt % were added to the PHB previously dissolved in chloroform. In the case of softening in the melt, a polymer paste was prepared, containing 70 wt % of plasticizers and 30 wt % of PVAc. The mixture was plasticized in a mixer, wherein time and temperature of the gelatinization were determined experimentally. Thermal degradation of preprared samples were specified by TGA. Values of Tg, Tm and Xc, was determined by DSC analysis. The samples plasticized in the melt were determined by the hardness of the material according to the Shore A scale and the Vickers scale.
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Development a new technology of liquefaction and soil stabilization
Chlachula, Jakub ; Krejčí, Pavel (referee) ; Drochytka, Rostislav (advisor)
Nowadays, efforts are being made to reduce the environmental impact on the planet even at soils management. Excavated soils are treated as waste and often end up in landfill or depot landfills. It is an effort to exploit these soils. By adding suitable stabilizing additives, features such as yield fluidity, moisture or compressive strength can be adjusted. This composite can be further liquefactioned by using water and suitable liquefiers or plasticizers. Such iquefactioned soils are a suitable self-compacting grouts dressing for excavation for the laying of utility grids, where it is necessary to fill the hole again. The advantage are low economic demands and the absence of excess waste. In the course of this thesis the situation of soil usability in the Czech Republic will be evaluated and possible technologies of soil adjusters will be described. Further, the known types of stabilizing additives and their influence on soil stabilization will be evaluated and verified. Then, different types of liquefying additives will be evaluated and verified. The aim of the thesis is to develop a new technology of liquefaction and soil stabilization.
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Výskyt ftalátů v potravním řetězci a jejich vliv na lidský organizmus
Kloudová, Vendula
The bachelor's thesis entitled Occurrence of phthalates in the food chain and their effect on the human organism discusses the issue of food contamination and its entry into the human body. The primary way the human body is exposed to phthalates is through the consumption of contaminated food. There are several ways in which phthalates enter the food chain. For example, contaminated feed is given to animals, resulting in the presence of phthalates in animal tissues. Subsequently, these contaminated raw materials are used in the production of food, leading to their presence in the final product. Due to their ubiquitous occurrence, this thesis also analyzes other routes of exposure to phthalates for the human body, such as cosmetic preparations or medical devices. The work first defines the physical and chemical properties of phthalates that have a significant influence on the contamination of the surrounding environment. Subsequently, it describes the metabolism of phthalates in the human body and possible ways in which they can be degraded. Furthermore, the acute and chronic toxicity of phthalates is defined here, which classifies phthalates as so-called endocrine disruptors that have an adverse effect on reproduction, prenatal and postnatal development, or carcinogenicity. Methods for detecting phthalates are also described in the thesis, and less toxic functional alternatives to phthalates are presented. Finally, legislative measures related to the issue are analyzed in the conclusion of the thesis.
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Dissolution of a drug from thin films based on plasticized PLGA derivatives
Kodytková, Simona ; Šnejdrová, Eva (advisor) ; Paraskevopoulou, Anna (referee)
CHARLES UNIVERSITY Faculty od Pharmacy in Hradec Kralove Department od Pharmaceutical Technology Author: Simona Kodytková Title od Diploma thesis: Dissolution of a drug from thin films based on plasticized PLGA derivatives Supervisor: PharmDr. Eva Šnejdrová, Ph.D. The aim of the presented work was to formulate liquid systems for the formulation of in situ thin films (FFS) based on copolymers D,L-lactic and glycolic acid (PLGA) and to study the effect of a combination of salicylic acid and methyl salicylate in film and the effect of their various concentrations on dissolution profiles. The theoretical section summarizes the general knowledge about the characteristics, substances used to formulate FFS and methods for their testing. In the experimental section, liquid systems forming in situ films by solvent evaporation were prepared, based on a linear or branched PLGA polymer containing salicylic acid as a poor water soluble drug, and methyl-salicylate as a multifuctional plasticizer, at different concentrations. The solubility test of salicylic acid, methyl salicylate and their mixtures, and dissolution tests of drug and plasticizer in phosphate buffer buffer pH 5.5 at 37 řC were performed. Salicylate analysis was performed by HPLC. Based on the results, it can be stated that faster dissolution of...
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Acyclovir release from mucoadhesive matrices
Šišáková, Lenka ; Šnejdrová, Eva (advisor) ; Dittrich, Milan (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Student: Lenka Šišáková Supervisor of Diploma thesis: PharmDr. Eva Šnejdrová, Ph.D. Title of Diploma thesis: Aciclovir release from mucoadhesive matrices The aim of this diploma thesis was the study of the mucoadhesive parameters of plasticized oligoester of lactic acid and glycolic acid and 3% mannitol as a branching monomer. Knowledge of dissolution testing of drug release from dosage form, principal theories and mechanisms of mucoadhesion and mucoadhesion testing of adhesive formulation is described in theoretical part. Matrices formed from terpolymer of D,L-lactic acid, glycolic acid branched with mannitol and 5 % aciclovir were examined in the experimental part. Triethylcitrate (TEC), ethylpyruvate (EP), methylsalicylate (MS) and ethylsalicylate (ES) were used as plasticizers. Dissolution test has been done. Hydrated mucin from porcine stomach was used as a base. Phosphate-citrate buffer pH 7.4 was used as a dissolution medium. Dissolution was defined as a quantity of released aciclovir in to the dissolution medium after 15, 30, 60 and 90 minutes. The quantity of the released aciclovir was defined by a spectrophotometry. In 90 minutes was released 43 % of aciclovir from the matrice...
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Biodegradable solid dispersion for application to mucous membranes
Janáková, Gabriela ; Šnejdrová, Eva (advisor) ; Dittrich, Milan (referee)
1. ABSTRAKT CHARLES UNIVERSITY Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Name of the student: Mgr. Gabriela Janáková Title of diploma thesis: Biodegradable solid dispersion for application to mucous membranes Consultant: PharmDr. Eva Šnejdrová, Ph.D. The aim of this work was to formulate solid dispersions for application to the mucosa and the skin in the form of a thin film and to study their dissolution properties. Solid dispersions were comprised of biodegradable copolymers of lactic acid and glycolic branched using 3% (3P) or 5% (5P) of pentaerythriol. They were prepared by a melting method with the addition of ethyl salicylate (ES) as a prodrug and plasticizer and optionally incorporating salicylic acid. As a dissolution medium phosphate buffer pH 7.4 was used. The theoretical part focuses on biodegradable polymers and solid dispersions. A faster course of salicylate release was observed in case of the polyester with higher molecular weight, higher branching ratio, and higher glass transition temperature. Higher content of ethyl salicylate slowed down salicylate release. After the incorporation of 5% salicylic acid into the polyester plasticized by ethyl salicylate, there was no expected elongation of salicylate release. The solid dispersion based on polyester...
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Properties of fibers based on polyhydroxybutyrate
Štulrajterová, Lujza ; Tocháček, Jiří (referee) ; Přikryl, Radek (advisor)
Táto práca sa zaoberá zvlákňovaním biopolymérov z taveniny. V teoretickej časti sú zhrnuté doterajšie poznatky o zvlákňovaní poly(3-hydroxy butyrátu) (PHB) a poly(mliečnej kyseliny) (PLA). Následne boli zvláknené polymérne zmesi na báze PHB s rôznym zložením, čo umožnilo štúdium vplyvu PLA, zmäkčovadiel a ich množstva na vlastnosti pripravených vlákien. Boli použité tri komerčné zmäkčovadlá (ATBC, PEG, A6) a dva experimentálne syntetizované. Zvláknenie bolo prevedené na troch rôznych zvlákňovacích linkách. Konvenčné zvlákňovacie linky s odťahovými rýchlosťami nad 150 m/min sa preukázali ako nevhodné pre spracovanie našich zmesí. Kvôli nedostatočnej pevnosti taveniny sú potrebné nízke odťahové rýchlosti. Boli pripravené vlákna s dĺžiacim pomerom 6,4; ktoré boli následne analyzované pomocou GPC, MDSC a ťahovej skúšky. Na základe nameraných teplôt skelného prechodu zmäkčovadlá ATBC a PEG vykázali lepšiu schopnosť zmäkčiť skúmané PLA/PHB zmesi. Vlákna obsahujúce A6 vykazovali najvyššiu pevnosť v ťahu (250 MPa) a modul pružnosti (2,7 GPa). Nakoniec bol skúmaný vplyv starnutia, tepla a vriacej vody na mechanické vlastnosti týchto vlákien.
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Development a new technology of liquefaction and soil stabilization
Chlachula, Jakub ; Krejčí, Pavel (referee) ; Drochytka, Rostislav (advisor)
Nowadays, efforts are being made to reduce the environmental impact on the planet even at soils management. Excavated soils are treated as waste and often end up in landfill or depot landfills. It is an effort to exploit these soils. By adding suitable stabilizing additives, features such as yield fluidity, moisture or compressive strength can be adjusted. This composite can be further liquefactioned by using water and suitable liquefiers or plasticizers. Such iquefactioned soils are a suitable self-compacting grouts dressing for excavation for the laying of utility grids, where it is necessary to fill the hole again. The advantage are low economic demands and the absence of excess waste. In the course of this thesis the situation of soil usability in the Czech Republic will be evaluated and possible technologies of soil adjusters will be described. Further, the known types of stabilizing additives and their influence on soil stabilization will be evaluated and verified. Then, different types of liquefying additives will be evaluated and verified. The aim of the thesis is to develop a new technology of liquefaction and soil stabilization.
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