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Energy of compressing and destructive energy of dry fillers
Červenková, Lucie ; Řehula, Milan (advisor) ; Musilová, Marie (referee)
Červenková Lucie - Rigorózní práce - 2006 This work deals with the evaluation of viscoelasticity on basis of force - displacement record. Theoretical part of the work characterizes tablets and fillers for direct compression, discusses the theory of destruction of tablets and presents the parameters of mechanical resistance of tablets. The aim of the work was the following of the influence of the type of a dry filler on displacement of the grinding process and to find out the dependence between the compression parameter E2 and parameter DE. The microcrystalline cellulose Avicel PH 102, mannitol, and lactose were used as fillers. It follows from the results that the destructive displacement in the case of microcrystalline cellulose is significantly longer than those of mannitol and lactose. Absolute or differential methods of record do not influence the destructive displacement. Microcrystalline cellulose in comparison with lactose and mannitol consumes less energy at compression and simultaneously has higher DE. Comparison of mannitol and lactose shows that mannitol consumes more energy at compressions and has also higher value of DE.
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Determining the compression behaviour of microcrystalline celluloses.
Coufal, Libor ; Řehula, Milan (advisor) ; Špaček, Vladimír (referee)
Coufal Libor, diploma paper, June 2009 Tablets are a very expanded dosage form. All new investigation in their technology are worth. While in pharmacopoeial method of measurement of mechanical strength of tablets evaluate by means of the strength at which the tablet breaks. This paper is based on the strength - course record. From this record, it is possible to ascertain other parameters of crushing process, such as the course of crushing, the crushing force and deformation energy. The radial strength, the volume deformation energy and deformation energy related to tablet weight are calculated from them. Tablets prepare from microcrystalline celluloses, hydroxyehylcelulose, powdered lactose monohydrate and substance called PharmDry (maltodextrine) were evaluated by means of these parameters. Results of this thesis shows descent of tensile strength in this order: microcrystalline cellulose Avicel PH-200, microcrystalline cellulose Avicel PH-102, maltodextrine, hydroxyethylcellulose and powdered lactose monohydrate. Kinetic characteristics of tablets descent in this order: microcrystalline cellulose Avicel PH-102, hydroxyethylcellulose, maltodextrine, microcrystalline cellulose Avicel PH-200 and powdered lactose monohydrate. Key words: strength - course record, course of crushing, crushing force,...
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Viscoelastic properties of microcrystalline cellulose and lactose
Sosvorová, Lucie ; Řehula, Milan (advisor) ; Špaček, Vladimír (referee)
The aim of this work was to evaluate the use of creep test during the compaction of microcrystalline celluloce Avicel PH 102, lactose FlowLac 100 and their mixtures in rates of 75:25, 50:50 and 25:75. Individual substances or mixtures were compressed by compression forces 0,25; 0,5; 1; 2; 3; 4; 5; 7,5; 10 and 15 kN. After the compression of each tablet a report describing the process of compression was procured. These dates were obtained by software connected with compression machine. Obtained relation bethween displacement and time was transfered to the relation bethween parameter J (creep compliance) and time. This relation was finally characterized by four basic parameters: E1 (immediate elasticity), E2 (retardet elasticity), P1 (plasticity) and FP (factor of plasticity). From the results we can see that microcrystalline celluloce Avicel PH 102 compared to lactose FlowLac 100 has lower elasticity and higher plasticity. With the decreasing value of microcrystalline celluloce Avicel PH 102 in the mixture the elasticity is inceased and plasticity decreased. Further was proved, that creep test method is usable in praxis for evaluation of pharmaceutical supplementary substances (fillers) used in the tablet manufacture. This test clearly valued the elasticity and plasticity by way of concrete numerical...
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Determination of the crushing process parameters for tablets with acetylsalicylic acid
Gallová, Zuzana ; Řehula, Milan (advisor) ; Musilová, Marie (referee)
Gallová Zuzana - Rigorózní práce - 2006 This work deals with the determination of parameters of destructive process for tablets containing acetylsalicylic acid. Dry filler microcrystalline cellulose is characterized in the theoretical part. Mechanical properties are also evaluated and theory of tablet destruction is described. The aim of the work was the determination of an optimal cycle rate and height of preloading. The determination was carried out with Acylpyrine using T1 - FRO 50 device. It follows from the results of the work that the suitable setting for measurement of mechanical resistance by means of T1 - FRO 50 instrument is cycle rate 0.6 mm/s and preloading 0.1 N.
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A study of the properties of tablets from coprocessed dry binder based on directly compressible starch and lactose.
Moučková, Eva ; Mužíková, Jitka (advisor) ; Řehula, Milan (referee)
The paper deals with the study of the properties of tablets from coprocessed dry binder StarLac. The properties under study included the tensile strength and disintegration time in dependence on compression force, addition of two lubricants (magnesii stearas, sodium stearylfumarate) in two concentrations (0,4. 0,8%) and a 50% addition of the active ingredient ascorbic acid. The compression forces were 15, 16, 17 kN, in the case of the tableting material with the active ingredient only 16 kN. The addition of magnesii stearas in a concentration of 0,4% increased the tensile strength, but in a concentration of 0,8% didn't. The same result is in the case of sodium stearyl fumarate for compression force 17 kN. The addition of lubricants increased the disintegration time of tablets, less in the case of Pruv. The addition of ascorbic acid decreased the tensile strength of tablets, the disintegration time was shorten. StarLac without and with magnesii stearas too offers the tablets with higher tensile strength and with shorter disintegration time then the physical mixture of Starch 1500 and Pharmatose DCL 15.
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Calculation of elasticity and plasticity of microcrystalline cellulose PH 102
Křivková, Blanka ; Řehula, Milan (advisor) ; Musilová, Marie (referee)
1 Abstract Calculation of Elasticity and Plasticity of Microcrystalline Celullose PH 102 Mgr. Blanka Křivková, 2007 Microcrystalline celullose is widely used as a filler for direct compression. Avicel PH 102 is very often used because of its size of particles (100 μm), appropriate, bulk volume, compressibility. The aim of Rigorous thesis was to calculate plasticity and elasticity using different methods, to describe Young's modulus of elasticity and complete confront plasticity from monitored microcrystalline cellulose. The plasticity was determined from graphs showing the decreasing trend of force on the time. For the evaluation was used three methods. The first one used "one-point" evaluation and put into rate value of maximal and minimal forces. The second one used "one-parameter" evaluation by the help of parameter t1 and third one "three-parameter" evaluation by the help of parameter t1, t2 and t3. Young's modulus of elasticity expresses stiffness of material and is very important for determination of plasticity. Two sections of curve from graphs showing the dependence of the plasticity on the compression force can be distinguished. The first one characterized the phase of precompression, second one characterized the plastic deformacion of tablets. We also confirmed the influence of different type of...
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Determining the compression behaviour of microcrystalline cellulose and calcium stearate
Brožová, Irena ; Řehula, Milan (advisor) ; Adámek, Roman (referee)
70 ABSTRACT This graduation theses deals with characterization of microcrystalline cellulose mixed with a lubricant, calcium stearate, by force-distance record and tablet relaxation . The theoretical part concerns with compaction process, energy parameters of force-distance record, classification and characterization of farmaceutical materials used in tablet production. The aim of experimental part was evaluation of compaction process and measuring of energy parameters. The force-distance record was obtain during the compaction process. The influence of compaction pressure and calcium stearate concentration in relation to compaction energy and tablet relaxation was observed. The result of this work was determination of the relationship of compaction pressure and calcium stearate concentration in relation to compaction energy and tablet relaxation. In some cases was observed a linearity characterized by an appropriate equation.
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Study of factors influencing weight of oral drops. 2.
Šímová, Sandra ; Šklubalová, Zdeňka (advisor) ; Řehula, Milan (referee)
Ten commercial packages of oral drops with seven different dropper tips have been tested in this thesis. The mass of a drop has been investigated in the dependence on density, surface tension, dynamic viscosity and dispensing angle. Physical and chemical properties of oral formulations influence significantly the dropping ability of dispensing systems as well as the mass of a drop. An explicit dropping condition has been deduced. It formulates relations among characteristic dimensions of the dispensing system, surface tension and density of the liquid. The validity of the dropping condition has been verified for all original commercial packages. A linear relationship between drop mass and viscosity has been determined experimentally; a weak decreasing dependence between necking diameter and viscosity has been found. A combined influence of density and surface tension on diameter of a drop has been explained. The mass of drop decreases significantly when the dispensing angle decreases from 90ř to 70ř. However, the variability of dose increases simultaneously due to wetting of dropper tip and possible formation of bigger drops. A patient should be informed about the necessity to drop the oral formulation upon strictly vertical position. This information has been missing at seven from ten original...
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Determination of the plasticity of mannitol
Šulková, Petra ; Řehula, Milan (advisor) ; Musilová, Marie (referee)
Šulková Petra - Rigorózní práce - 2006 This work deals with the evaluation of plasticity of mannitol by means of the stress relaxation method. Theoretical part of the work describes preparation of the tablets by direct compression, theory of compression and characterizes mannitol. The aim of the work was the determination of mannitol plasticity, following of the influence of the dwell time on residual plasticity and determination of the dependence of residual plasticity on compression force. The plasticity was measured by means of T1 - FPO 50 device. It follows from the results of the work that the increase in dwell time of mannitol tablets lead to the increase of plasticity. Mannitol had the parameter A 56.62 % and B -0.369% kN-1 .
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Compressibility of different batches of the drug Simvastatin.
Havelková, Adéla ; Řehula, Milan (advisor) ; Ondrejček, Pavel (referee)
This thesis deals with the characterization of pressing energy using the force-displacement diagram. The theoretical part defines the substance - simvastatin - and excipients which could occur in unknown samples. Also energies of pressing process, methods of assessment of force-displacement diagram for different substances and factors which affect pressability and thus the pressing energy are described there. The aim of the experimental part of the thesis was to characterize the energy profile using force-displacement diagram of eight batches of preparation simvastatin and to find applicable method of assessment. Tablets were pressed from each batch of preparations using a T1-FRO 50 machine at three pressing forces 5, 10, and 15 kN. Obtained parameters E2, E3, Elis and Pl were evaluated using three methods: method of outlying values, method of analysis of average for one factor and method of analysis of average for two factors. The most suitable method for assessment of divergent values is the method of analysis of average for two factors thanks to its complex character. This method showed lower values of the parameters E1, E2, Elis and Pl for batches E, G and H which could be caused by larger particles and higher moisture of granulate.
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