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Optimizing Flow and Segregaton Properties of Lactose/Microcrystalline Cellulose Mixture for Tablet Compression.
Zámostný, P. ; Kreibichová, B. ; Hofmanová, D. ; Kulaviak, Lukáš ; Zelenková, K. ; Růžička, Marek
The present study deals with optimizing the flow and segregation properties of levocetirizine hydrochloride formulation, where the delay between homogenization and tablet compression was found to affect the tablet content uniformity. In addition to API, the base formulation comprised spray dried lactose monohydrate, milled lactose monohydrate 200 mesh, Avicel PH 101 microcrystalline cellulose, and minor excipients. Several alternative mixtures were prepared using the same total composition, but different grades of lactose and microcrystalline cellulose. These mixtures were then tested for the segregation behavior in an in-house segregation device and the flow properties using the Freeman FT4 powder rheometer. The segregation tests showed the grade of lactose is essential for mixture in-flow segregation. While SD lactose mixtures increased the API content in a direction countercurrent to flow, the milled lactose mixtures segregated API concurrently. Mixtures using both lactose grades showed combined effect, resulting in the least segregation due to the two segregation processes competing with each other. However, the segregation was extremely sensitive to ageing of the mixture. It was also found that each type of lactose causes a different flow regime of the mixture in process vessels. In order to improve the content uniformity of the tablets, it was found the volumetric flow regime of transport to tablet press is required as well as the aggregate formation should be prevented.\n
Plný tet: PROCEEDINGS OF THE 3RD INTERNATIONAL CONFERENCE ON CHEMICAL TECHNOLOGY -  PDF
Plný text: content.csg - PDF
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Extraction of Carotenoids from Selected Plants
Rousková, Milena ; Maléterová, Ywetta ; Hanika, Jiří ; Šolcová, Olga
The great interest which lutein and all carotenoids have aroused during the last decades is conditioned not only by their interesting structure but by their biological and physiological importance. It is evident that their application in agriculture, food and pharmaceutical industry has a great potential for the future. Thus study of their isolation from natural resources is very important nowadays.
Plný tet: SKMBT_C22015083114530 - PDF
Plný text: content.csg - PDF
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Pressure Hydrolysis of Protein in Waste of Chicken Cartilage and Feathers in the Presence of Carbon Dioxide
Hanika, Jiří ; Šolcová, Olga ; Kaštánek, P.
Proteins hydrolysis of chicken cartilage and feathers were carried out at increased temperature (till 120 oC) and in the presence of carbon dioxide (partial pressure 10 20 bar), which dissociates in water solution forming an acidic environment supporting the reaction. Carbon dioxide was easily detachable from the reaction mixture at the end of process. Bench scale tests were performed using a mixed autoclave (volume 2.5 lt, mixing time 5 hr). The resulting aqueous solution of amino acids contained in the same representation as peptides forming collagen and keratin of raw material. The reaction conversion was proportional to carbon dioxide partial pressure.
Plný tet: SKMBT_C22015083108550 - PDF
Plný text: content.csg - PDF
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Mechanochemical Preparation of Alumina-Ceria
Jirátová, Květa ; Spojakina, A. ; Tyuliev, G. ; Balabánová, Jana ; Kaluža, Luděk ; Palcheva, R.
Ceria containing catalysts play an essential role in heterogeneous catalytic processes. However, ceria shows poor thermal stability and low specific surface area and therefore, many studies have been done to improve its properties by combination with other oxides. Alumina-ceria is substantial component of the three ways catalysts, due to the ceria ability to function as the buffer of oxygen and to enhance the oxygen storage capacity of the catalysts. Ceria in these catalysts also functions as structural promoting component, increasing alumina stability towards thermal sintering. Promising method of oxides preparation, very interesting and simple but not sufficiently studied yet is a mechanochemical synthesis. Here we report on the synthesis of nano-sized alumina, ceria and ceria-alumina of various compositions by a wet solid phase mechanochemical reaction of hydrous aluminum, and/or cerium nitrate with ammonium bicarbonate after addition of a small amount of water. The aim of this contribution is to study processes being in progress during synthesis of the mixed oxides, interaction between components and their mutual effect on the properties of resulting products. The phase evolution during mechanical milling and the subsequent heat treatment of precursors were studied by X-ray diffraction, DTA/TG, H2-TPR, NH3-TPD, CO2-TPD, N2 adsorption at -195°C, IR, and XPS spectroscopy. Alumina and mixtures of alumina with different quantities of CeO2 (1- 18 wt. %) were synthesized by mechanochemical method from aluminum nitrate, cerium nitrate and ammonia bicarbonate.
Plný tet: SKMBT_C22015083108560 - PDF
Plný text: content.csg - PDF
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