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Hydrophobic ion pairing as a strategy to improve the encapsulation efficiency of PLGA nanoparticles.
Laviaha, Lizaveta ; Šnejdrová, Eva (advisor) ; Smékalová, Monika (referee)
Charles University Faculty of Pharmacy in Hradec Kralove Department of Pharmaceutical Technology Author: Lizaveta Laviaha Title of thesis: Hydrophobic ion pairing as a strategy to improve the encapsulation efficiency of PLGA nanoparticles. Supervisor: PharmDr. Eva Šnejdrová, Ph.D. Сonsultant: Mgr. Vladislav Frolov The aim of this thesis was to increase the encapsulation efficiency (EE) and capacity of PLGA nanoparticles (NPs) for the hydrophilic antibiotics gentamicin (GEN) and vancomycin (VAN). The method of hydrophobic ion pairing (HIP) and docusate sodium as anionic surfactant (AOT) were chosen. PLGA nanoparticles loaded with VAN or GEN, or their AOT complexes were prepared with optimized methods. Nanoparticles with VAN and GEN were prepared by the double-emulsion method (W1/O/W2), for GEN-AOT the single emulsion method (O/W) was used, and nanoparticles with VAN-AOT were prepared by suspension-emulsion method (S/O/W). Stable NPs with a size of 108 to 223 nm with a polydispersity lower than 0.2 were obtained. The influence of PLGA concentration on the size of NPs was found. The low zeta potential of the nanoparticles was related to steric stabilization by the non-ionogenic stabilizer Poloxamer 407. SEM images confirmed the spherical shape of the NPs. Encapsulation efficiency and loading capacity...
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Effect of croscarmellose sodium on the properties of tablets prepared from spray-dried material
Mauerová, Alžběta ; Svačinová, Petra (advisor) ; Smékalová, Monika (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of: Department of Pharmaceutical Technology Supervisor: PharmDr. Petra Svačinová, Ph.D. Consultant: PharmDr. Tereza Vařilová Student: Alžběta Mauerová Title of Thesis: Effect of croscarmellose sodium on the properties of tablets prepared from spray-dried materiál In this thesis, the effect of the addition of croscarmellose sodium (CMC) on the properties of the prepared tablets was investigated. CMC was added to the individual mixtures in concentrations of 1, 2, 3 and 4% (w/w). The mixtures were prepared by spray drying and contained different amount of meloxicam (MX). Tablets were compressed from these mixtures. Subsequently the disintegration time, crushing force, pycnometric density, DSC characteristics and dissolution tests were performed. The porosity and tensile strength of the tablets was further calculated from the obtained values. The results of the individual tests were compared with standard tablets without the disintegrant. According to the results obtained, the disintegration time was shortened after the addition of CMC for most of the mixtures. Furthermore, it was shown that the addition of CMC resulted in a decrease in porosity in the investigated samples. Due to the plastic deformation of CMC, the tensile strength...
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Basic in vitro evaluation of silver nanoparticles
Čermáková, Gabriela ; Holas, Ondřej (advisor) ; Smékalová, Monika (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Supervisor: PharmDr. Ondřej Holas Ph.D. Consultant: doc. PharmDr. Ivona Pávková Ph.D. Student: Gabriela Čermáková Title of Thesis: Basic in vitro testing of silver nanoparticles This thesis focuses on basic in vitro testing of the efficacy of silver nanoparticles (AgNP) of 10 nm (AgNP10) and 30 nm (AgNP30) against the infectious agent Francisella tularensis (F. tularensis). The aim was to assess the potential of AgNP as a possible therapeutic strategy against tularaemia and to evaluate the efficacy associated with different nanoparticle sizes. AgNP were prepared by a chemical reduction method. The sensitivity of bacterium F. tularensis influenced by AgNP10 or AgNP30 was tested by the microdilution method to determine the inhibitory concentration (IC). Testing AgNP10 in the concentration range of 5-30 µg/ml based on multiple experiments was able to determine IC100, which corresponds to a concentration of 20 µg/ml. For AgNP30, the IC100 could not be accurately determined due to time and technological problems. During testing, it was necessary to verify the stability of AgNP in different culture media. The results obtained led to the identification of a suitable medium for susceptibility testing of F....
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Characterization of material for gelatin-based ultrasound brain phantom
Sasková, Marcela ; Smékalová, Monika (advisor) ; Svačinová, Petra (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Supervisor: Mgr. Monika Smékalová, Ph.D. Consultant: MUDr. Michael Bartoš Student: Marcela Sasková Title of thesis: Characterization of material for gelatin-based ultrasound brain phantom This thesis deals with the characterization of the material for a gelatin-based ultrasound phantom, which will subsequently serve as a teaching aid for medical students to localize brain tumors and practice ultrasound imaging. In the experimental part, samples of gelatin gels cross-linked with glutaraldehyde at different concentrations of scattering particles and glycerol were prepared to measure the acoustic parameters (speed of sound and attenuation coefficient) and the gray scale of the imaging and to perform thermal analysis. Gelatin is an inexpensive, readily available, non-toxic material that is highly soluble in hot water, making it a suitable starting material for phantom preparation. SiC and Al2O3 particles (0,3 µm and 3 µm) can be used to increase the echogenicity of the gelatin-based gel. Thanks to the scattering particles, it was possible to vary the gray level of the image and the attenuation coefficient depending on their amount. The best results were achieved with SiC alone, where the gray...
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Spray drying of chitosan suspension with different content of active substance
Plotová, Lucie ; 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: Lucie Plotová Title of Thesis: Spray drying of chitosan suspension with different content of active substance In this work, a spray-dried suspension of chitosan with different content of active substance was evaluated. By spray drying, solid particles were formed from the suspensions of various drug concentration, which were further evaluated to assess their properties. The formed suspensions contained, in addition to chitosan, 20, 30, 40 or 50 mg of meloxicam and sodium lauryl sulphate as surfactant and were subsequently dried at 170 řC, 190 řC or 210 řC. The prepared particles were evaluated using an optical microscope and a scanning electron microscope (SEM). Furthermore, the rate and amount of released active substance were evaluated by dissolution, and the thermal properties of the particles were evaluated by differential scanning calorimetry (DSC). According to the results from the optical microscope and SEM, it was shown that the particles of the spray-dried samples formed clusters of individual particles and irregular shapes can be seen in the images. Small particles of meloxicam are visible on the surface of the platelet-shaped chitosan...
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Polymeric nanoparticles for poorly water soluble drugs delivery
Nekolová, Martina ; Holas, Ondřej (advisor) ; Smékalová, Monika (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Mentor: PharmDr. Ondřej Holas, Ph.D. Student: Martina Nekolová Title of thesis: Polymeric nanoparticles for poorly water-soluble drugs delivery Polymeric nanoparticles represent a modern drug form. One of the main advantages is influencing the pharmacokinetic properties of the administered substance - e.g. increasing solubility in water. They enable the targeted delivery of the drug to the affected tissue and this way minimize adverse effects. This could be of great benefit to the therapy of cancer or inflammatory diseases. Both the target tissue and the nanoparticles must have some specific properties. For particles, it is, for example, size and surface charge. The aim of this work was to prepare nanoparticles with a substance poorly soluble in water, represented by curcumin. The particles were prepared by the nanoprecipitation method with different types of poly(lactic-co-glycolic acid) (PLGA) copolymer. A 50:50 linear PLGA polymer and a branched PLGA A2 polymer were used. The prepared nanoparticles were compared on several parameters - particle size and polydispersity, encapsulation efficiency (EE), drug-loading capacity (DLC) and dissolution profile. PLGA 50:50 was found to provide...
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Dissolution study of PLGA nanoparticles
Budigová, Aneta ; Smékalová, Monika (advisor) ; Holas, Ondřej (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Consultant: Mgr. Monika Smékalová Ph.D. Student: Aneta Budigová Title od thesis: Dissolution study of PLGA nanoparticles PLGA nanoparticles are used as nanoparticle carrier systems for targeted distribution and controlled release of drugs. The aim of this diploma thesis was to prepare PLGA nanoparticles with encapsulated fluorescein and dexamethasone acetate and subsequently dissolve them in various media. Fluorescein as a model substance was chosen because of its low solubility in water, which is close to that of dexamethasone acetate. Nanoparticles were prepared by the nanoprecipitation method. The following dissolution media were chosen for fluorescein dissolution: 0.01M PBS, saline, acetate buffer, and artificial lysosomal fluid (ALF). Dissolution of PLGA nanoparticles with dexamethasone acetate was performed in 0.01 M PBS. The nanoparticles were also evaluated for size, PDI, zeta potential and encapsulation efficiency. The willingness of fluorescein to release from PLGA nanoparticles decreased in the order: acetate buffer saline, 0.01M PBS and ALF. Lowering the pH of the dissolution medium from 7.4 (PBS, saline) to 5.5 (acetate buffer) resulted in the release of approximately twice as much...
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Preparation and evaluation of nanoparticles for targeted treatment of inflammatory diseases
Wurzel, Natalie ; Holas, Ondřej (advisor) ; Smékalová, Monika (referee)
Charles University, Faculty of Pharmacy in Hradci Králové Department of Pharmaceutical Technology Supervisor: PharmDr. Ondřej Holas, PhD Consultant: Mgr. Barbora Boltnarová Student: Natalie Wurzel Title of Thesis: Preparation and evaluation of nanoparticles for targeted treatment of inflammatory diseases Nanoparticles are used in the health sciences for, among other things, targeted drug delivery. This is used for the therapy of cancer and chronic inflammatory diseases. The aim of this diploma thesis was to prepare nanoparticles suitable for targeted treatment of inflammatory diseases. The task was to determine the ideal concentration of the active substance, which would ensure high encapsulation efficiency and drug loading. The difference between nanoparticles prepared from PLGA 5/5E and PLGA 7/3A was also investigated. Nanoparticles were prepared by the nanoprecipitation method. The matrix of the nanoparticles was composed of PLGA with different ratios of lactic acid and glycolic acid. Acetone was used as the organic solvent. The encapsulated active substance was the anti-inflammatory dexamethasone acetate. The aqueous phase was consisted of a 0.1% aqueous solution of Pluronic F-127. The evaluated parameters of the resulting nanoparticles included size, polydispersity index, zeta potential,...
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Polymeric nanoparticles for poorly water soluble drugs delivery
Nekolová, Martina ; Holas, Ondřej (advisor) ; Smékalová, Monika (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Mentor: PharmDr. Ondřej Holas, Ph.D. Student: Martina Nekolová Title of thesis: Polymeric nanoparticles for poorly water-soluble drugs delivery Polymeric nanoparticles represent a modern drug form. One of the main advantages is influencing the pharmacokinetic properties of the administered substance - e.g. increasing solubility in water. They enable the targeted delivery of the drug to the affected tissue and this way minimize adverse effects. This could be of great benefit to the therapy of cancer or inflammatory diseases. Both the target tissue and the nanoparticles must have some specific properties. For particles, it is, for example, size and surface charge. The aim of this work was to prepare nanoparticles with a substance poorly soluble in water, represented by curcumin. The particles were prepared by the nanoprecipitation method with different types of poly(lactic-co-glycolic acid) (PLGA) copolymer. A 50:50 linear PLGA polymer and a branched PLGA A2 polymer were used. The prepared nanoparticles were compared on several parameters - particle size and polydispersity, encapsulation efficiency (EE), drug-loading capacity (DLC) and dissolution profile. PLGA 50:50 was found to provide...
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Formulation of vancomycin loaded PLGA nanoparticles for local treatment of musculoskeletal infections I.
Petrášová, Ivana ; Šnejdrová, Eva (advisor) ; Smékalová, Monika (referee)
Charles University Faculty of Pharmacy in Hradec Kralove Department of Pharmaceutical Technology Author: Ivana Petrášová Title of thesis: Formulation of PLGA nanoparticles with vancomycin for local treatment of musculoskeletal infections I Supervisor: PharmDr. Eva Šnejdrová, Ph.D. The treatment of musculoskeletal infections requires the presence of high antibiotics concentration at the infection site. However, high doses of orally administered drugs cause the risk of increased systemic toxicity and serious adverse effects. Targeted drug delivery, currently one of the main areas of pharmaceutical research, represents a suitable option of a treatment without excessive burden on the organism. This diploma thesis focuses on the formulation of a therapeutic system for the local treatment of musculoskeletal infections in the form of polymer nanoparticles containing the antibiotic vancomycin. Due to the need of incorporation of a hydrophilic antimicrobial substance into them, the suspension-emulsion method of their preparation was used. Different concentrations of polyvinyl alcohol stabilizer and tripentaerythritol branched hydrophobic polymer poly(D,L- lactide-co-glycolide) were used for the preparation. Within the study the size of nanoparticles, polydispersity, zeta potential, encapsulation efficiency...
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