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Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Candidate Mgr. Žofie Jarolímová Supervisor doc. PharmDr. Zdeňka Šklubalová, Ph.D. Title of Doctoral Thesis Study of flow and consolidation behaviour of binary mixtures of Cellets and filler for preparation of multilayer tablets The manufacture and quality of solid dosage forms is influenced mainly by flow, consolidation and compaction properties of powder excipients. In this work, the behaviour of pellets made of microcrystalline cellulose (cellets), which might be used as a drug carrier in multilayer tablets, and their binary mixtures with microcrystalline cellulose was studied. More than 20 powder excipients commonly used in tablet production and their binary mixtures were involved in preliminary studies. Measuring of the angle of repose, Hausner ratio and the mass flow rate through a hopper orifice was influenced by the particle shape, size and the width of the particle size distribution. In order to identify easily the free flowing substances, the hopper orifice having 10 mm diameter was useful. Excellent flow properties were confirmed for cellets with conventional testing methods thanks to their spherical shape and narrow particle size distribution. The avalanche testing using a rotational drum...

Charles University, Faculty of Pharmacy in Hradec Králové Department: Pharmaceutical Technology Candidate: Ing. Hana Hurychová Supervisor: doc. PharmDr. Zdeňka Šklubalová, Ph.D. Title of Doctoral Thesis: Study of static and dynamic flow properties of pharmaceutical excipients Flow properties are among the most significant characteristics of pharmaceutical materials. Recent modern technologies allow preparation of particles with modified surface properties and flow behaviour for the conventional as well as new excipients. In this work, the static (compressibility index, Hausner ratio, angle of repose, shear testing) and dynamic (flow rate, avalanche testing) flow properties of a wide variety of excipients, their particle size fractions and selected model mixtures were evaluated. In particular, attention was paid to modelling of the flow rate by the equation prospectively suitable for use in the standardization of flow testing in pharmaceutical technology. The power equation in which the equation parameter is a direct prediction of the flow rate through an orifice having a unit diameter is recommended. The basic granulometric characteristics of particles were completed with the particle fractal dimension (pDF) and the bulk fractal dimension (bDF). Although a relatively strong correlation between the...

Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department Pharmaceutical technology Candidate Mgr. Petra Svačinová Supervisor Prof. PharmDr. Miloslava Rabišková, CSc. Title of Doctoral Thesis Influence of lubricants on viscoelastic parameters of compaction process This thesis deals with an evaluation of lubricant's influence on viscoelastic parameters of compaction process. The force-displacement record and stress relaxation test were used for this evaluation. This study evaluates the viscoelastic parameters on three fillers intended for direct compression, i.e. microcrystalline cellulose Avicel PH-200, lactose Lactochem Fine Crystals and calcium hydrogen phosphate dihydrate Emcompress. Magnesium stearate and modified colloidal silica Syloid were used as lubricants at concentrations of 0.5 % and 1 %. Particle size and shape and specific surface area were determined for all used excipients. Flow properties were studied for individual fillers and also for their mixtures with lubricants. Subsequently, tablets were compressed from fillers and mixtures using force-displacement record and stress relaxation test, and viscoelastic parameters were evaluated. The applied compression forces for both methods were 5 kN, 10 kN and 15 kN. The hardness of tablets was measured. The results show...