|
|
Hybrid polymeric-lipid nanoparticles as drug carriers
Žemličková, Simona ; Holas, Ondřej (advisor) ; Smékalová, Monika (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of: Pharmaceutical Technology Consultants: PharmDr. Ondřej Holas, Ph.D. Student: Simona Žemličková Title of thesis: Hybrid polymeric-lipid nanoparticles as drug carriers The work is focused on hybrid polymer-lipid nanoparticles, their advantages obtained from polymer and lipid part, purpose of surface modification, basic properties of nanoparticles, methods of preparation, modification of preparation conditions and use of nanoparticles in medicine. The aim of the experimental part was to prepare nanoparticles composed of polyester and lipid by emulsion evaporation method and nanoprecipitation. Two types of linear polymer poly (lactic-co-glycolic acid) and phosphatidylcholine were used in various ratios. The surfactant used for stabilization was poloxamer Pluronic® F127 and the organic solvents were ethyl acetate and acetone. Curcumin served as a model active substance. The effect of lipid and surfactant on the size and zeta potential of nanoparticles was evaluated. Modification of preparation conditions, which included many process parameters, also influenced the monitored parameters. Encapsulation effectivity and drug loading were also tested. Dissolution tests were performed. It was found that size of nanoparticles...
|
|
|
Evaluation of flow properties, compressibility and tablet properties of mixtures containing microcrystalline cellulose and TRI-CAFOS ® 200-7.
Višňovský, Daniel ; Svačinová, Petra (advisor) ; Smékalová, Monika (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of: Pharmaceutical Technology Consultant: PharmDr. Petra Svačinová, Ph.D. Student: Daniel Višňovský Title of Thesis: Evaluation of flow properties, compressibility and tablet properties of mixtures containing microcrystalline cellulose and TRI-CAFOS ® 200-7 Direct compression technology has simplified the tabletting process by allowing immediate compression of tablets without the need of granulation. However, this applies high demands on the tableting mixture. In particular, the excipients must exhibit good compressibility and excellent flow properties. Lubricants are important for influencing these properties, but may ultimately have a negative effect on the properties of the tablets. Due to its structure and properties, Tri-Cafos ® 200-7 is a material that could be used as a lubricant. The main task of this work was the evaluation of Tri-Cafos® as a lubricant in tableting. Magnesium stearate was used as a reference substance. In mixtures with microcrystalline cellulose, the flow properties were evaluated by the flow trough an orifice method and the Hausner ratio. After subsequent compression of tablets with three compression forces (5 kN, 7.5 kN and 10 kN), the compression process was evaluated using the force-displacement...
|
|
|
Process of nanoparticulate systems purification optimization
Strnadová, Kristýna ; 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: Kristýna Strnadová Title of thesis: Process of nanoparticulate systems purification optimization The aim of the diploma thesis was to compare three purification methods - centrifugation, size- exclusion chromatography and dialysis, to find the optimal method and its conditions for purification of nanoparticles based on poly(lactic-co-glycolic acid) composed of lactic acid and glycolic acid monomers in a ratio of 50:50. Mentioned purification methods were compared mainly in terms of encapsulation efficiency and recovery yield. Nanoparticles purified by centrifugation were prepared with stabilization of one of the following surfactants: poloxamer 407, poly(vinyl alcohol), cetrimonium bromide (in concentration of 0,1 %, 1 % and 2 %) or sodium cetyl stearyl sulfate (in concentration of 0,01 % and 0,025 %). Purified water and a solution of the stabilizer in the corresponding concentration were used as redispersion media during centrifugation. Centrifugation was performed at 7200 rcf in repeated cycles of 15 min each. Size-exclusion chromatography and dialysis were performed with nanoparticles stabilized with 0,1% poloxamer 407. Silica gel, Sephadex®...
|
|
|
Hybrid polymeric-lipid nanoparticles as drug carriers
Žemličková, Simona ; Holas, Ondřej (advisor) ; Smékalová, Monika (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of: Pharmaceutical Technology Consultants: PharmDr. Ondřej Holas, Ph.D. Student: Simona Žemličková Title of thesis: Hybrid polymeric-lipid nanoparticles as drug carriers The work is focused on hybrid polymer-lipid nanoparticles, their advantages obtained from polymer and lipid part, purpose of surface modification, basic properties of nanoparticles, methods of preparation, modification of preparation conditions and use of nanoparticles in medicine. The aim of the experimental part was to prepare nanoparticles composed of polyester and lipid by emulsion evaporation method and nanoprecipitation. Two types of linear polymer poly (lactic-co-glycolic acid) and phosphatidylcholine were used in various ratios. The surfactant used for stabilization was poloxamer Pluronic® F127 and the organic solvents were ethyl acetate and acetone. Curcumin served as a model active substance. The effect of lipid and surfactant on the size and zeta potential of nanoparticles was evaluated. Modification of preparation conditions, which included many process parameters, also influenced the monitored parameters. Encapsulation effectivity and drug loading were also tested. Dissolution tests were performed. It was found that size of nanoparticles...
|
|
|
Evaluation of flow properties, compressibility and tablet properties of mixtures containing microcrystalline cellulose and TRI-CAFOS ® 200-7.
Višňovský, Daniel ; Svačinová, Petra (advisor) ; Smékalová, Monika (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of: Pharmaceutical Technology Consultant: PharmDr. Petra Svačinová, Ph.D. Student: Daniel Višňovský Title of Thesis: Evaluation of flow properties, compressibility and tablet properties of mixtures containing microcrystalline cellulose and TRI-CAFOS ® 200-7 Direct compression technology has simplified the tabletting process by allowing immediate compression of tablets without the need of granulation. However, this applies high demands on the tableting mixture. In particular, the excipients must exhibit good compressibility and excellent flow properties. Lubricants are important for influencing these properties, but may ultimately have a negative effect on the properties of the tablets. Due to its structure and properties, Tri-Cafos ® 200-7 is a material that could be used as a lubricant. The main task of this work was the evaluation of Tri-Cafos® as a lubricant in tableting. Magnesium stearate was used as a reference substance. In mixtures with microcrystalline cellulose, the flow properties were evaluated by the flow trough an orifice method and the Hausner ratio. After subsequent compression of tablets with three compression forces (5 kN, 7.5 kN and 10 kN), the compression process was evaluated using the force-displacement...
|
guest ::
RSS feed.