National Repository of Grey Literature 111 records found  beginprevious41 - 50nextend  jump to record: Search took 0.00 seconds. 
Optimalisation of preparation of biodegradable nanocarriers of drugs
Kvasnicová, Lucia ; Holas, Ondřej (advisor) ; Šnejdrová, Eva (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical technology Candidate: Mgr. Lucia Kvasnicová Consultant: PharmDr. Ondřej Holas Ph.D. Title of Thesis: Optimising the preparation of biodegradable drug nanocarriers The theoretical part was devoted to different types of nanoparticles, especially those which were prepared from poly(α-hydroxy acids). Other chapters were devoted to methods of their preparation- either from pre- prepared polymers or from directly polymerized monomers and the use of nanoparticles in medicine. The experimental part was aimed at optimizing the preparation of various derivates of poly(lactic-co-glycolic acid) (PLGA) using a nanoprecipitation method with medicated model drug. Rhodamine B was used as a model drug and poloxamer Pluronic® F127 was used as a stabilizer. The size of nanoparticles, their index of polydispersity (PDI) and the zeta potential were measured in the experimental part. Recovery yield, encapsulation efectivity and relative encapslation efectivity were also measured. The results showed that acetone was more suitable solvent than acetonitrile. The most appropriate weight of polymers was 20 mg, when the values of PDI were less than 0,2 and the size of nanoparticles was between 100 nm to 300 nm, so these samples had high...
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...
Evaluation of rheological properties of terbinafine hydrochloride creams
Stehlíková, Dagmar ; Šnejdrová, Eva (advisor) ; Holas, Ondřej (referee)
CHARLES UNIVERSITY Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Candidate: Mgr. Dagmar Stehlíková Consultant: PharmDr. Eva Šnejdrová, Ph.D. Title of Thesis: Evaluation of rheological properties of terbinafine hydrochloride creams The aim of the rigorous work was to evaluate the rheological properties of creams with terbinafine hydrochloride at different stages of the formulation of a generic preparation using a suitable methodology and their comparison with the commercial preparation Lamisil 10 mg/g crm. (GlaxoSmithKline), which was specified as a standard. The theoretical part deals with the characterization of generic drugs, pharmaceutical and therapeutic equivalence. Tests suitable for measuring the flow properties of semi-solid preparations and evaluation methods are presented. The properties of terbinafine hydrochloride and the process of developing generic semi-solid formulations are summarized. Testing was performed at 25 řC on a Kinexus Pro+ rotational rheometer using cone-plate geometry. The flow properties of the creams were evaluated by nonequilibrium flow and viscosity curves, which were analysed by the power law model and Herschel-Bulkely model. The coefficient of consistency, the index of flow behaviour and the yield point were expressed. The...
Study of the surfactants effect on polymer nanoparticle parameters
Moravcová, 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...
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%....
Development and characterization of modified polysulfone hemodialysis membranes by means of immobilized neutrophil elastase inhibitors
Morgošová, Kristína ; Kučera, Radim (advisor) ; Holas, Ondřej (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Chemistry and Pharmaceutical Analysis University of Porto Faculty of Pharmacy Department of Chemical Sciences Department of Biological Sciences Candidate: Kristína Morgošová Supervisor: assoc. prof. PharmDr. Radim Kučera, Ph.D. Consultants: prof. Maria da Conceição Branco da Silva, Ph.D. prof. Maria Alice dos Santos Silva Gomes Martins, Ph.D. Susana Maria Santos Rocha, Ph.D. Title of diploma thesis: Development and characterization of modified polysulfone hemodialysis membranes by means of immobilized neutrophil elastase inhibitors. Chronic kidney disease (CKD) is a major health and financial burden, mainly because of the costly renal replacement therapy and treatment associated. The last stage, end-stage renal disease, is associated with high morbidity and mortality rate, generally due to cardiovascular complications. Chronic inflammation is frequently present in CKD patients, which is enhanced by the long term intra-dialytic recurrent contact between blood and hemodialysis (HD) membrane and further contributes to development of atherosclerosis. Contact with the artificial material of HD membranes leads to oxidative stress and neutrophil activation with release of neutrophil serine proteases such as human...
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...

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