The aim of this diplom thesis was development of the reverse phased high performance liquid chromatography (RP-HPLC) for analysis the aliphatic hydrocarbons with long chain and optimalization of this method. In theoretical part is described occurrence and properties of a hydrocarbons, also used separation methods and detectors - evaporative light scattering detector (ELSD) and matrix assisted laser desorption ionization with time of flight analyzer. In experimental part is described izolation of cuticular hydrocarbons from a fly Neobellieria bullata. It was study experimental conditions of separation and detection izolated hydrocarbons. It was performed deep optimalization of conditions on RP-HPLC - composition of mobile phase, gradient, mobile phase flow rate and column temperature. Method optimalization was done by ELSD. It was used kombination of two solvents to mobile phase - acetonitrile : ethylacetate, mobile phase stream 0,8 ml/min and column temperature 50řC were found as optimal conditions for analytical separation. This method were aplicated for analysis cuticular hydrocarbons from fly specie Neobellieria bullata. During separation were collected fractions and then fractions were determined on MALDI-TOF. It was found 37 aliphatic hydrocarbons which included 25 up to 47 carbons and 0 to 3...

The theoretical part of this diploma work is focused on the polymeric nanoparticles, their properties and advantages connected with them. There are introduced also particular types of organic and inorganic nanoparticles and methods of their preparation. The great attention was directed on biodegradable polymers in particular to poly lactic-co-glycolic acid, which was used in experimental part as carrier for base of terbinafine branched to tripentaerythritol. PLGA is the most suitable copolymer for practice because of good explored its physical, chemical and biological properties, methods of preparation and factors affecting degradation. The aim of this work was to find suitable emulsifier with suitable concentration for preparation of nanoparticles containing the base of terbinafine, suitable solvent for terpolymer and optimal concentration of emulsion to reach the highest yield of terbinafine without any exceptional loss. How it was mentioned, as carrier was used terpolymer of poly lactic-co-glycolic acid with tripentaerythritol. As technique of preparation of nanoparticles was used emulsification by evaporating of organic solvent (solvent evaporation method). During the experimental work we found out some of conclusions, it goes to reduce of polydispersity with increasing concentration of...

Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Candidate: Karolína Valíková Supervisor: doc. RNDr. Milan Dittrich, CSc. Diploma thesis title: Formulation and study of the antimicrobial agent A literary overview of selected characteristics of silver nanoparticles is presented in the diploma thesis. Size measurement methods are described, while considerable attention is paid to photon correlation spectroscopy (PCS), which was used in the experimental part of this diploma thesis. Various methods of silver nanoparticle synthesis are outlined. Later part of the text is focused on the application of silver nanoparticles in areas concerning human health - mainly for the purposes of medicine, disinfection and as components of cosmetic products. Possible toxic effects of silver nanoparticles on human organism are also discussed. The focus of the thesis is in the experimental part. Stability of microparticles in suspensions used for product formulation was studied, as well as the PCS instrument's capability to distinguish the size distribution of particles in aqueous medium in highly polydisperse systems and in highly diluted systems. It was proven that microparticles have a spontaneous ability to form flocks, nonionic surfactants in 0.1%...

Charles Univerzity in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Candidate: Veronika Müllnerová Consultant: Doc. RNDr. Milan Dittrich, CSc. Title of thesis: Impact of molecular weight and the grade of branching of aliphatic oligoesters on their hydrolytic degradation Theoretical part of the thesis deals with behavior, properties and applications of biodegradable polyesters, mainly copolymers of lactic and glycolic acid (PLGA). This part concerns degradation, erosion and release mechanism. Furthermore, it describes properties that influence the drug release kinetics from systems based on PLGA. The final section of theoretical part is focused on the in situ forming implants, whose carrier of active substance is biodegradable polyester. The experimental part analyzes the influence of different pH of the medium within physiologically common boundaries and also the influence of ionic force on the degree of swelling and polymer erosion. These degradation parameters have been studied on three potential polyester carriers of active substances - PLGA, M3 (terpolymer of lactic and glycolic acid with mannit) and T3 (terpolymer of lactic and glycolic acid with tripentaerythritol). Polymer bodies were kept in temperature of 37řC inside phosphate-citrate buffers with...

In the theoretical part of this thesis are described the synthesis, properties and mechanism of biodegradation of aliphatic polymers - polylactic acid, polyglycolic acid and their copolymer PLGA. There are also discussed the possibilities of modifying the properties, such as block copolymer PEG-PLGA synthesis. Summary informations concerning the production and use of biodegradable polymers are also shortly described. The aim of the experimental part was to observe the effect of PLGA polymer matrix size and ionic strength of the aqueous medium on the polymer swelling and erosion. Samples with weight 150 mg and 1000 mg were placed into 37 řC citrate buffer with pH 6. Each of the used mediums had various concentration c [0; 0,125; 0,25; 0,5; 1]. Measurement was carried out in period of 28 days. Values of degree of swelling and of erosion were measured. The pulsion behavior of swelling in both sample sizes was confirmed. However, the sample size has a strong impact on the rate and extent of swelling. It was demonstrated that larger samples disintegrate faster which is explained by a higher rate of autocatalysis within the polymer matrix. The results demonstrated also the effect of ionic strength on erosion when isotonic solution suppressed erosion rate.

Farmaceutická fakulta, Katedra farmaceutické technologie, Hradec Králové, 2014 Vypracovala: Markéta Valentová Školitel: Doc. RNDr. Milan Dittrich, CSc. ABSTRACT STUDY OF POLYESTER DRUG CARRIERS DEGRADATION USING THE DSC METHOD The aim of this work was focused on the study of relations among various parameters of degradation process, such as time-dependent range of glass transition temperature, swelling, erosion, and molar weight decrease. Two model polyesters of two type architectures of polyester molecules were used and monitored during two-week period. In the theoretical part of this diploma thesis are in details described biopolymers with stimulus responsive activity and exploitation of these materials in various biomedical applications in the topic of tissue engineering. The experimental part of this work is directed into the study of molecule degradation parameters, eventually into simulated biodegradation in the in vitro conditions of two different in the type polyesters with the contrast polyester molecule constitution. It was demonstrated that parameter Mn decreases towards the limit values. Between the values of molar weight and glass transition temperature is not Flory-Fox relation in the advanced phase of degradation process. The erosion of the material begins after the lag-time in the dependency...

Medicínské aplikace tvoří z biodegradabilních alifatických polyesterů na bázi polylaktonů, polylaktidů a jejich kopolymerů velmi atraktivní skupinu materiálů. Metody přípravy těchto polymerů jsou založeny na polymeraci za otevření kruhu laktonů a laktidů. Mnoho organokovových sloučenin se vyznačují jako účinné a vysoce selektivní katalyzátory těchto polymerací, avšak je známo, že deriváty těžkých kovů jsou škodlivé pro lidský organismus. Z tohoto důvodu je v dnešní době rostoucí zájem o vývoj účinných „green“ polymeračních systémů pro syntézu biodegradabilních alifatických polyesterů. Předložená disertační práce se věnuje přípravě alifatických polyesterů založených na polykaprolaktonu, polylaktidu, polyglykolidu a zejména jejich kopolymeru pomocí organického katalyzátoru náležícího do skupiny N-heterocyklických karbenů (NHC) bez přítomnosti centrálního atomu těžkého kovu. Literární rešerše je zaměřená na pokroky v polymeraci za otevření kruhu (ROP) cyklických esterů (laktonů a laktidů) pomocí organických "metal-free" katalyzátorů. Nicméně, nebyly nalezeny žádné studie, kde se pro přípravu polyglykolidu nebo jeho kopolymerů využívá polymerace za otevření kruhu pomocí karbenových katalyzátorů. Experimentální část práce popisuje přípravu a vlastnosti 1,3-di-tert-butylimidazol-2-ylidenu (NHC-tBu) karbenu připraveného z jeho stabilní chloridové soli. Další část je zaměřena na přípravu polyesterů z cyklických monomerů, jmenovitě L-laktidu, D, L-laktidu, glykolidu a -kaprolaktonu pomocí NHC-tBu jako katalyzátoru. Byla zkoumána nová metoda přípravy termosenzitivního amfifilního triblokového kopolymeru na bázi biodegradabilního hydrofobního polylaktidu, polyglykolidu a biokompatibilního hydrofilního polyethylenglykolu (PLGA–PEG–PLGA) pomocí připraveného NHC-tBu. Dále byly studovány podmínky polymerace (například: přečištění monomeru, teploty polymerace, různé typy rozpouštědel, poměry rozpouštědla ku monomeru a nebo různé poměry iniciátoru ku katalyzátoru). Na závěr byl připravený PLGA–PEG–PLGA kopolymer srovnán s kopolymerem připraveným pomocí Sn(II)2-ethylhexanoátu. NHC-tBu se v přítomnosti PEG projevil jako účinný katalyzátor polymerace za otevření kruhu laktonu a laktidů. Připravené kopolymery dosahovaly vysoké konverze monomeru (70 – 85%) s polydisperzitou (Mw/Mn okolo 1,2). Byl připraven PLGA–PEG–PLGA kopolymer se dvěma fázovými přechody (sol-gel a gel suspenze) a gelační teplotou v rozmezí 35 – 43 °C. Změny polymeračních podmínek neměly ve většině případů zásadní vliv na chemické vlastnosti kopolymeru, jako jsou molekulová hmotnost nebo polydisperzita, ale měly významný vliv na visko-elastické vlastnosti.