National Repository of Grey Literature 111 records found  beginprevious47 - 56nextend  jump to record: Search took 0.00 seconds. 
Formulation of freeze dried tablets for buccal application of vaccines
Vuová, Ngoc Lien ; Šklubalová, Zdeňka (advisor) ; Holas, Ondřej (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of: Pharmaceutical Technology Mentor: Doc. PharmDr. Zdeňka Šklubalová, Ph.D. Student: Ngoc Lien Vuová Title of Thesis: Formulation of freeze dried tablets for buccal application of vaccines Mucosal vaccines represent an attractive way of vaccination with an advantage of inducing both systemic and local immunity. The aim of this diploma thesis was designing a composition of freeze-dried tablets for buccal administration of a model Bordetella pertusis vaccine. The easy removal from blister, firmness and aesthetic appearance as well as the appropriate taste and mucoadhesivity were the required product quality parameters. The excipients were characterised by differential scanning calorimetry, osmolality and pH measurement; the mechanical properties and disintegration time of freeze-dried tablets were evaluated. Among the variety of studied excipients and their combinations, dextran 40 as the main component of the preparation provided the best results. For the further modification of properties, the addition of fish gelatin, iota carrageenan and macrogol 300 is suitable. Freeze-dried tablets containing trehalose, mannitol and povidon 25 did not achieve the desirable quality parameters. Freeze- dried tablets containing iota carrageenan...
Acidoresistant polymeric nanoparticles: preparation and assessment
Semrádová, Adélka ; Holas, Ondřej (advisor) ; Svačinová, Petra (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of: Pharmaceutical Technology Consultants: PharmDr. Ondřej Holas, Ph.D. Mgr. Jana Kubačková Student: Adélka Semrádová Title of thesis: Acidoresistant polymeric nanoparticles: preparation and assessment Use of oral drug delivery nanosystems has a great potential in therapy of inflammatory bowel disease, which includes Crohn's disease and ulcerative colitis. Nanosized delivery systems are more efficiently accumulated at the inflammatory site, targeting specifically macrophages to resolve inflammation locally and reduce systemic adverse effects. The aim of this research was to prepare pharmaceutical formulations based on polymeric nanoparticles. Three types of poly(lactide-co-glycolide) - two linear and one branched polymer - together with the acidoresistant polymer cellulose-acetate phthalate (CAF) in various ratios were used to prepare nanoparticles by nanoprecipitation method. Rhodamine B was used as model active substance. The effect of acidoresistant component content on size and zeta potential of the nanoparticles was evaluated. Furthermore, dissolution tests were performed at both acidic and physiological pH. It was found that CAF doesn't have any significant effect on size of the particles and their stability....
Biodegradable polymeric nanoparticles preparation
Bacskaiová, Silvia ; Holas, Ondřej (advisor) ; Dittrich, Milan (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of: Pharmaceutical technology Consultant: PharmDr. Ondřej Holas, Ph.D. Student: Silvia Bacskaiová Title of Thesis: Biodegradable polymeric nanoparticles preparation The present scientific progress in an important rate conduces to nanomedicine development, which aims to reengineering of cancer pharmacotherapy and other substantial diseases. The main intention of this graduation thesis is the study of surface-active chemical's effects on the final properties of nanoparticles. The theoretical part is focused on the nanoparticles likedrugs vehicles, synthesis of biodegradable nanoparticles, themselves applications in the cancer therapy, diseases accompanied by inflammations, vaccination and for another different purposes. The theoretical part also contents characterization of active and passive goal- directed distribution by diseases, microencapsulations, synthesis of nanoparticles by polymerization and from previously synthesized polymers and definition of physical- chemical properties of nanoparticles. The experimental part is more extensive and concerned with the optimalization of reaction conditions of nanoparticles synthesis, with selection of advisable concentracion and type of surfactant. In the experimental part were...
Study of the surfactants effect on polymer nanoparticle parameters
Kostíková, Katarína ; Holas, Ondřej (advisor) ; Šnejdrová, Eva (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Consultant: PharmDr. Ondřej Holas, PhD. Student: Katarína Kostíková Title of thesis: Study of the surfactants effect on polymer nanoparticle parameters The main aim of this Diploma thesis was to examine whether the use of various stabilizers has any effect on the resultant size of prepared nanoparticles and to find out which type of stabilizer is the most appropriate in terms of preparation of the nanoparticles of the necessary size, adequate polydispersity and steadiness. The preparation of nanoparticles was based on the use of sodium cholate as a surfactant and polymer PLGA (poly (lactid-co-glycolic acid)) consisting of monomers of lactic and glycolic acids. Nanoparticles were prepared by means of nanoprecipitation method. Sodium cholate solution has always been prepared in water in different concentration: 0.005%, 0.01%, 0.02%, 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 1%, 2%, and 5%. The following have been used as stabilizers: poloxamer 407, polyvinyl alcohol, cetrimonium-bromide (CTAB), and polysorbate 20, all of them in concentration of 0.1% and sorbitan-monostearate in concentration of 0.01%. Measurement of the size of created nanoparticles was performed using the device Zetasizer at the...
Lyophilization of polymeric nanomaterials
Švehlíková, Ingrid ; Holas, Ondřej (advisor) ; Smékalová, Monika (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Consultant: PharmDr. Ondřej Holas, PhD. Student: Ingrid Švehlíková Title od thesis: Lyophilization of polymeric nanoparticles Lyophilization is a widely used drying method with extensive application possibilities in the drug preparation. Its importance in pharmacy is growing because it is one of the important methods of stabilizing active substances, especially proteins. A detailed understanding of the properties of the drug and the physicochemical phenomena of the individual phases of lyophilization is a basic prerequisite for the preparation of a safe, effective and stable drug. Biomedical nanoparticles as drug carriers are the type of the dosage forms in which lyophilization is also used. A series of lyophilization experiments were performed using trehalose, mannitol, dextran and xylitol as cryo and lyoprotectant. The parameters assessed were particle size, PDI, appearance and lyophilisate reconstitution. The properties of nanoparticles prepared by nanoprecipitation from PLGA polymer were evaluated. Furthermore, experiments were performed to validate the deep-freezing method as an alternative method to lyophilization for long-term storage of nanoparticles. The nanoparticles were stored in...
Preparation of polymeric fluorescent nanopyrticles
Širajová, Daniela ; Holas, Ondřej (advisor) ; Svačinová, Petra (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Consultant: PharmDr. Ondřej Holas, PhD. Student: Daniela Širajová Title of thesis: Preparation of polymeric fluorescent nanoparticles Nanoparticles based on biodegradable polyesters are a widely used platform for targeted drug delivery and subsequent controlled release. The aim of this diploma thesis was to prepare and optimize the preparation of polymeric nanoparticles with a fluorescent dye as a model substance. The nanoprecipitation method was used to prepare the nanoparticles. Nanoparticles prepared from two types of PLGA polymers (COOH terminated and ester terminated) were evaluated and compared. The surfactant and stabilizer were used in various concentration ratios to optimize the preparation. The surfactant was sodium cholate at concentrations of 0.1%, 0.5%, 1%, 2% and 5%. The nanoparticles were stabilized with Pluronic F-127 poloxamer at concentrations of 0.1%, 0.5% and 1%. Nanoparticles were compared in terms of encapsulation efficiency, particle size and zeta potential. In a dissolution experiment, the amount of fluorescein released was evaluated and compared as a function of time (48 hours) with acid-terminated PLGA and sodium cholate at concentrations of 0.1% and 2%....
Synthesis and biological evaluation of tacrine-amantadine derivatives
Král, Jan ; Opletalová, Veronika (advisor) ; Holas, Ondřej (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Chemistry and Drug Control Student: Jan Král Supervisor: doc. RNDr. Veronika Opletalová, Ph.D. Consultant: PharmDr. Jan Korábečný, Ph.D. Title of diploma thesis: Synthesis and biological evaluation of tacrine-amantadine derivatives Alzheimer's disease (AD) is a fatal neurodegenerative disorder of brain. Nowadays there is only paliative treatment available, which can be further subdivided into two groups: acetylcholinesterase inhibitors (AChEIs) and N-methyl-D-aspartate (NMDA) receptor antagonist. Donepezil, rivastigmine and galantamine represents AChEIs currently available for AD treatment. Tacrine is the first AChEIs to be approved for AD treatment, however, it was withdrawn from the market due to its side effects, especially due to its hepatotoxicity. 7-Methoxytacrine (7-MEOTA) is less toxic tacrine derivative preserving pharmacological profile of tacrine. This diploma thesis describes synthesis of multifunctional 7-MEOTA- amantadine derivatives as potential drugs to confront AD. Using Ellmanʼs method, we have established their efficacy to inhibit acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) in vitro. All new synthesized hybrids from 7-MEOTA- amantadine family proved to be better...
Effect of the concentration of amino-decorated polyamidoamine dendrimers with ethylenediamine core at the (trans)dermal delivery of 5-fluorouracil
Chladová, Pavlína ; Paraskevopoulos, Georgios (advisor) ; Holas, Ondřej (referee)
Effect of the concentration of amino-decorated polyamidoamine dendrimers with ethylenediamine core at the (trans)dermal delivery of 5-Fluorouracil Pavlína Chladová Dendrimers are synthetic, symmetrically tree-like branched molecules. They are composed of repeating units (monomers). They have high density of surface functional groups and spherical shape in solution. Since their molecular weight is highly controllable, they are characterized by monodispersity and this is their main difference from classical polymers. Dendrimers have a wide spectrum of applications in biomedicine. Due to the empty space between the branches of the molecule, they can encapsulate drugs, and by conjugation and complexation to the surface groups, they are able to carry even larger drug molecules. Thus, dendrimers can be used as drug delivery systems. In addition, they have been used for skin application of several active molecules, either as topical or transdermal delivery. Suitable properties for (trans)dermal application have been demonstrated for dendrimers which consist of monomers with amine groups and are connected with amide bonds. The goal of this thesis was the preparation of dendrimers with these characteristics and the evaluation of their concentration influence to the permeability of 5-Fluorouracil (5-FU) to human...
Effect of the generation of amino-decorated polyamidoamine dendrimers with ethylenediamine core at the (trans)dermal delivery of 5-fluorouracil
Houšková, Denisa ; Paraskevopoulos, Georgios (advisor) ; Holas, Ondřej (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Supervisor: Dr. Georgios Paraskevopoulos, Ph.D. Consultant: Mgr. Anna Nová ková Author: Denisa Houšková Title of thesis: Effect of the generation of amino-decorated polyamidoamine dendrimers with ethylenediamine core at the (trans)dermal delivery of 5-fluorouracil. Dendrimers can be defined like highly branched, star-shaped macromolecules with nanometer-scale dimensions and unlimited applications in both biological and materials sciences. Polyamidoamine (PAMAM) dendrimers have been used to effectively enhance the (trans)dermal drug delivery of several active substances. Inspired by the structure of PAMAM dendrimers, a new class of dendrimers was designed having amino-functionalized periphery and ethylenediamine core. A repeating motif of bis(2-aminoethyl)glycine was used for generation growth up to the third generation. The new dendritic molecules of zero, first, second and third generation were tested for their ability to enhance the deposition of 5-fluorouracil in the different layers of human skin ex vivo by using Franz diffusion cells. The results suggest that the new dendrimers, at a concentration of 20 mg/mL in 60 % propylene glycol in water as vehicle, are able to deliver 5-fluorouracil at the...
Nanofiltration
Hudečková, Hana ; Kučera, Radim (advisor) ; Holas, Ondřej (referee)
Charles University, Faculty of Pharmacy in Hradec Králové, Department of Pharmaceutical Chemistry and Pharmaceutical Analysis Nanofiltration Diploma thesis Candidate: Hana Heidrová Supervisor: doc. PharmDr. Radim Kučera, Ph.D. Consultant: PharmDr. Tomáš Holas, Ph.D. Nanofiltration is a pressure-driven membrane process which is characterized by using semipermeable membranes with approximately 1 nm pores. This method is used abundantly for the separation of substances with low molecular weight. It is used for example in the process of product isolation in pharmaceutical industry. This diploma thesis is focused on the description of the behaviour of three commercially produced nanofiltration membranes and also on testing of their potential use in the production of ergot alkaloids. The theoretical part is focused especially on the description of pressure-driven membrane processes, the use of nanofiltration in various areas and also on current and historical use of ergot alkaloids in therapy and on the description of their properties. The practical part is oriented particularly on examination of effect of various experimental parameters on the retention of selected ergot alkaloids (primarily of lysergic and isolysergic acid). The results are compared and critically analysed. Keywords: pressure-driven...

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