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Measurement of stress relaxation of mixtures of microcrystalline cellulose and calcium hydrogen phosphate intended for the preparation of tablets with theophylline
Hofmanová, Markéta ; Šklubalová, Zdeňka (advisor) ; Ondrejček, Pavel (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of: Pharmaceutical technology Consultant: Doc. PharmDr. Sklubalova Zdenka, Ph.D. Student: Marketa Hofmanova Title of Thesis: Measurement of stress relaxation of mixtures of microcrystalline cellulose and calcium hydrogen phosphate intended for the preparation of tablets with theophylline The powder mixtures with theophylline were studied from the aspect of viscoelastic properties of used materials and tablets tensile strength. In the theoretical part the thesis concerned with description of materials which were used in the mixtures. They are: Microcrystalline cellulose Comprecel 102, calcium hydrogen phosphate anhydrate Di-Cafos A150, calcium hydrogen phosphate dihydrate Di-Cafos D160 and lactose SpheroLac 100. The thesis also deals with the stress relaxation test. The stress relaxation test, its evaluation by several methods and its use in the pharmacy and in different fields are described. The experimental part deals with viscoelastic characteristics of the mixtures. These characteristics were evaluated by stress relaxation test with maximal compression force 10 kN and dwell time 180 s. Also the tensile strength was evaluated. The highest values of parameters of elasticity A1-3 and plasticity P1-3 were measured in...
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The effect of particle size on lactose compressibility
Havlíková, Natálie ; Ondrejček, Pavel (advisor) ; Svačinová, Petra (referee)
Charles University in Prague, Faculty of Pharmacy in Hradci Králové Department of: Pharmaceutical technology Consultant: PharmDr. Pavel Ondrejček, Ph.D. Student: Natálie Havlíková Title of Thesis: The effect of particle size on lactose compressibility It is known that the particle size of the compressed material plays an important role in the manufacture of tablets. It affects the properties of intermediate and final products. In this thesis the properties of tablets made of two lactose types, which were used as model fillers, were studied. These were Tablettose® 80 and Lactopress® Anhydrous. In both lactose types, five sieved size fractions of the particle size ranging from 9 to 346µm and their original unsieved mixture were used. The compaction forces ranging from 2 to 10kN were used for tablet preparation. Magnesium stearate was used for external lubrication. The evaluation of the prepared tablets was done mainly by using the pharmacopoeial methods. The evaluated parameters were friability, disintegration time and hardness. Furthermore, the elasticity of the tablets and the evaluation using the force-displacement method parameters were assessed. From the results of this work, it is not possible to unambiguously determine the advantage of one particular fraction size in the comparison to the...
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Determination of flow properties of mixtures for preparation of tablets containing theophylline
Brunettová, Monika ; Šklubalová, Zdeňka (advisor) ; Mužíková, Jitka (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of: Pharmaceutical Technology Consultant: Doc. PharmDr. Šklubalová Zdeňka, Ph.D. Student: Brunettová Monika Title of Thesis: Determination of flow properties of mixtures for preparation of tablets containing theophylline The aim of this diploma thesis was to characterize the flow properties and moisture content of mixtures for preparation of tablets containing theophylline. Parameters were monitored depending mainly on the content of the fillers, that were dicalcium phosphate, microcrystalline cellulose and lactose. Twenty-five prepared mixtures with different ratios of these fillers were evaluated. Flowability was evaluated by three methods stated in Czech Pharmacopoeia 2009 - compressibility index and Hausner ratio, flow through an orifice and angle of repose. Moisture content was evaluated as a weight loss during drying. Mixtures containing dicalcium phosphate and lactose proved more appropriate in terms of flowability, their flow properties are passable. However, according to the moisture content, mixture with microcrystalline cellulose are more preferable.
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Effect of paracetamol on the parameters of compression equation
Mařanová, Lucie ; Řehula, Milan (advisor) ; Ondrejček, Pavel (referee)
Evaluation of the tableting mixtures containing the paracetamolum by the parameters of the equation of compression The diploma thesis deals with effect of paracetamol on the parameters of compression equation. These parameters characterize compression process in the individual phases of compression: precompression phase, phase of elastic deformation and phase of plastic deformation. Paracetamolum was studied in the five mixtures, where it occurred in different ratio with microcrystalline cellulose. Looseness, Carr's index and Hausner ratio were evaluated for each mixture. The sizes of reductions ai, sizes of energies Ei and Ri, "half-pressures" pHi and the velocity constants 1/ti were calculated using three-exponential equation of compression for the individual phases of pressing. The results showed poor flow properties of tableting mixtures and thus its unsuitability for direct compression. The results of the study have revealed that increasing amounts of paracetamolum in the mixture increase reduction of volume a1 and velocity of volume change 1/t1 in dependence on the amount of the extruded air and decrease the required energy due to the smooth surface and less friction during the precompression phase. Reduction of volume a2 decrease with the increase of content of paracetamol due to...
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Evaluation of tensile strength of tablets containing theophylline
Janoutová, Hana ; Šklubalová, Zdeňka (advisor) ; Ondrejček, Pavel (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Consultant: Doc. PharmDr. Zdeňka Šklubalová, Ph.D. Student: Hana Janoutová Title of Thesis: Evaluation of tensile strength of tablets containing theophylline The aim of this thesis was to determine tensile strength of tablets containing theophylline. Tensile strength was studied as a function of the composition of mixtures of the used fillers and especially on their ratio. In the theoretical part, the used materials - lactose SpheroLac 100, microcrystalline cellulose Comprecel 102, dibasic calcium phosphate dihydrate Di-Cafos D160, anhydrous dibasic calcium phosphate Di-Cafos A150, theophylline and magnesium stearate are described. This work also evaluates force-displacement record, tensile strength and various factors that affect tensile strength. Parameters of force-displacement record and tensile strength of the tablets compressed with compresssion force 10 kN were evaluated in the experimental part. The measured results show that higher values of precompression energy (E1) and energy of plastic deformation (E2) were detected in mixtures A, C and E which contain Comprecel 102, and the lowest values were detected in mixtures B which contain Sphero-Lac 100 and Di-Cafos D160. Values of energy...
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Evaluation of disintegration time of tablets containing theophylline
Brtnová, Soňa ; Šklubalová, Zdeňka (advisor) ; Mužíková, Jitka (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of: Pharmaceutical Technology Thesis supervisor: Doc. PharmDr. Zdeňka Šklubalová, Ph.D. Consultant: Mgr. Pavel Ondrejček Student: Soňa Brtnová Title of Thesis: Evaluation of disintegration time of tablets containing theophylline The influence of used fillers on energetic profile of compression, especially influence on disintegration time of tablets with theophylline as a model drug, was studied in this thesis. Four tablet fillers were studied - microcrystalline cellulose Comprecel 102, lactose SpheroLac 100, calcium hydrogen phosphate anhydrous Di- Cafos A150 and calcium hydrogen phosphate dihydrate Di-Cafos D160. Tablets contained different proportion of two fillers, theophylline as a model drug and lubricant magnesium stearate. Tablets were compressed by the same compaction force 10 kN. The force- displacement record was evaluated using the particular energies of compaction process. Parameters of compaction process were influenced mostly by Comprecel 102. According to results there is no possibility to replace Di-Cafos D160 with Di-Cafos A150 in the mixtures. It was also found that SpheroLac 100 and Di-Cafos D160 shows similar behavior. Time of disintegration of tablets is mostly dependent on the used fillers. Tablets...
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Evaluation of compressibility of tableting mixtures containing theophylline using a compaction equation
Matyášová, Andrea ; Šklubalová, Zdeňka (advisor) ; Svačinová, Petra (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department: Department of Pharmaceutical Technology Consultant: Doc. PharmDr. Zdeňka Šklubalová, Ph.D. Student: Andrea Matyášová Title of Thesis: Evaluation of compressibility of tableting mixtures containing theophylline using a compaction equation This thesis is aimed at the evaluation and comparison of excipients used in production of tablets. The compaction process of these excipients was evaluated using the parameters of the compaction equation. The mixtures of four fillers in various ratios were evaluated. These mixtures contained also theophylline as model drug and magnesium stearate as lubricant. The used three-exponential equation was previously developed by doc. RNDr. Milan Řehula, CSc. By using this compaction equation the volume reductions, speeds of volume reductions and consumed energies were calculated and evaluated. The results of this work showed that particular used fillers have different effect on the compaction process flow. That is caused primarily by different behavior of these materials during compaction and by formation of different types of bonds. Also the need of thorough cleaning and drying of compaction aid before compaction was confirmed.
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Influence of fillers and disintegrants type on properties of tablets with high dose drug.
Tranová, Thao ; Mužíková, Jitka (advisor) ; Svačinová, Petra (referee)
Charles University, Faculty of Pharmacy in Hradci Králové Department of: Pharmaceutical technology Consultant: doc. PharmDr. Jitka Mužíková, Ph.D. Student: Thao Tranová Title of Thesis: Influence of fillers' and disintegrants' type on properties of tablets with high dose drug The work engages in the study of fillers' and extragranular superdisintegrants' influence on properties of tablets with high dose drug. Two types of granulate with lactose or microcrystalline cellulose were produced in high shear granulator. Eleven tablets groups with different type and amount of superdisintegrants were prepared from the granulates. Tablets contained 2 %, 3.7 %, 5.4 % of sodium croscarmellose or 2 % and 5.4 % of crospovidone. The tested parameters of tablets were friability, hardness, disintegration time and density. Accelerated stability studies lasting 6 months at temperature of 40 řC and relative humidity 75 % were done. The tablets were evaluated after 1.5, 3 and 6 months. All tablets had adequate friability, hardness, disintegration and density at T0. Increasing concentration of superdisintegrant decreased disintegration time. Tablets containing microcrystalline cellulose and sodium croscarmellose disintegrated faster than tablets containing lactose or crospovidone. Tablets with sodium croscarmellose had...
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Study of flow and consolidation behaviour of binar mixtures of Cellets and filler for preparation of multilayer tablets
Jarolímová, Žofie ; Šklubalová, Zdeňka (advisor) ; Franc, Aleš (referee) ; Zámostný, Petr (referee)
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...
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Study of flow and consolidation behaviour of binar mixtures of Cellets and filler for preparation of multilayer tablets
Jarolímová, Žofie ; Šklubalová, Zdeňka (advisor) ; Franc, Aleš (referee) ; Zámostný, Petr (referee)
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...
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