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Preparation and characterization of polyhydroxybutyrate-based particles
Kopřivová, Lenka ; Šindelář, Jan (referee) ; Pospíšilová, Aneta (advisor)
This bachelor's thesis deals with the preparation of particles with a modified surface based on poly 3 hydroxybutyrate and the subsequent characterization of both modified and untreated particles. The particles were examined with a vision for future replacement for non degradable commodity microplastics in the cosmetics industry, as they are capable of biodegradation. The following chemicals were used for surface treatment: zinc stearate solution, lipase, hydrophobic silane (hexadecyltrimethoxysilane) and cationic surfactant. Next, the properties of the resulting modified particles were studied in comparison with unmodified poly 3 hydroxybutyrate and polyurethane-based powder, which is currently used in the cosmetic industry, and therefore served as a standard for sensory analysis. All samples were subjected to SEM and EDS analysis, FTIR spectroscopy and sensory analysis. Then, the following properties were measured: wettability, bulk density and particle size distribution by laser diffraction. Wettability was measured on compressed tablets from the powders using static contact angles. It was found that the hydrophobicity of particles treated with silane and zinc stearate increased, whereas the particles treated with cationic surfactant increased in hydrophilicity. The results measured from the contact angle and other analyses led to the conclusion that the surface treatment with lipase was not successful. Sensory analysis showed that the surface treatments did not affect the deterioration of the sensory properties compared to the original untreated PHB powder and that an untrained evaluator cannot tell the differences in pleasantness between the samples therefore, we can consider them as pleasant as the standard we determined.
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The use of milling and co-milling procedures for preparation of interactive mixtures
Jezerská, Jana ; Šklubalová, Zdeňka (advisor) ; Kvítek, Libor (referee) ; Vitková, Zuzana (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of: Pharmaceutical Technology Candidate: Mgr. Jana Jezerská Supervisor: doc. PharmDr. Zdeňka Šklubalová, Ph.D. Consultant: Ing. Jakub Koktan, Ph.D. Title of Doctoral Thesis: Utilization of technological procedures of milling and co-milling in the preparation of interactive mixtures The dissertation thesis is an annotated summary of the publication and research activities of the author, Mgr. Jana Jezerská (maiden name Brokešová). The thesis is focused on the preparation of binary interactive powder mixtures which consist of the micronized drug particles adhered onto the larger particles of an excipient (a carrier). The binary powder mixtures were prepared by mixing and/or co-milling and characterized by granulometric methods; crystallinity (thermal analysis, X-ray powder diffractometry), the flow properties (shear cell, avalanche properties) and the surface energy were evaluated as well. The dissolution rate of model drugs was estimated using a flow-through powder dissolution cell (USP-4). The used statistical model (central composite design) enabled to establish optimal milling conditions in a ball mill (the milling speed, the milling time, the size of milling balls) for five powder carriers. Based on quadratic response surface,...
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The use of milling and co-milling procedures for preparation of interactive mixtures
Jezerská, Jana ; Šklubalová, Zdeňka (advisor) ; Kvítek, Libor (referee) ; Vitková, Zuzana (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of: Pharmaceutical Technology Candidate: Mgr. Jana Jezerská Supervisor: doc. PharmDr. Zdeňka Šklubalová, Ph.D. Consultant: Ing. Jakub Koktan, Ph.D. Title of Doctoral Thesis: Utilization of technological procedures of milling and co-milling in the preparation of interactive mixtures The dissertation thesis is an annotated summary of the publication and research activities of the author, Mgr. Jana Jezerská (maiden name Brokešová). The thesis is focused on the preparation of binary interactive powder mixtures which consist of the micronized drug particles adhered onto the larger particles of an excipient (a carrier). The binary powder mixtures were prepared by mixing and/or co-milling and characterized by granulometric methods; crystallinity (thermal analysis, X-ray powder diffractometry), the flow properties (shear cell, avalanche properties) and the surface energy were evaluated as well. The dissolution rate of model drugs was estimated using a flow-through powder dissolution cell (USP-4). The used statistical model (central composite design) enabled to establish optimal milling conditions in a ball mill (the milling speed, the milling time, the size of milling balls) for five powder carriers. Based on quadratic response surface,...
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