In the pharmaceutical industry uniform flow of powders is one of the most important considerations in solid dosage manufacture. Improper feeding of powders from storage hoppers into dye-presses can lead to inconsistent product quality, causing economic and health impacts. Investigation into the properties affecting powder flow is crucial. There were four objectives of the current research: 1. To determine the effect of moisture on the flow (Jenike flow index, Hausner Ratio and Carr Index, static and dynamic angle of repose) of selected pharmaceutical powders. 2. To study the effect of particle shape and size on Jenike flow index for selected starch and pharmaceutical powders. 3. To determine the effect of mixture compositions on the Jenike flow index of ordered mixtures of selected pharmaceutical powders. 4. To develop a novel flowability tester based on electrical capacitance tomography (ECT) that measures the dynamic angle of repose of powders.<p>To address the first objective, to determine the effect of moisture content on the flow of four pharmaceutical powders; an active pharmaceutical ingredient (API), aspartame, hydroxypropyl methylcellulose (HPMC), and Respitose® ML001 were selected. The API and Respitose® powders were found to be nonhygroscopic and were tested at near zero moisture contents only (in this case 0.31% and 0.19% respectively). Aspartame was tested at moisture contents of 0%, 2%, 5% and 8% and HPMC at moisture contents of 0%, 2%, 5% and 10%. Powder flowability was measured using the Jenike shear index, the Hausner Ratio, the Carr Index and the static and dynamic angles of repose. The Jenike flow index of aspartame increased from 0.885 to 3.65 with an increase in moisture content, which was attributed to the formation of large, round agglomerates. The Jenike flow index of HPMC decreased from 3.28 to 2.65 with an increase in moisture content, which was attributed to the increasing strength of liquid bridges. The Jenike flow index was the only flowability indicator to capture this complex behaviour. <p>In order to address the second objective, five starches (cow cockle, barley, rye, rice and tapioca), as well as four pharmaceutical ingredients (an API, aspartame, HPMC, and Respitose® ML001), were characterised for size and shape, and then tested for flowability. Powder flowability was measured using the Jenike shear test, the most widely accepted flowability standard in the pharmaceutical industry. It was found that the Jenike flow index decreased linearly with decreasing aspect ratio and decreasing roundness for the powders investigated. It was also determined that particle shape had a greater impact on flowability than size for powders under 30 microns in diameter. <p>To address the third objective, ordered mixtures of pharmaceutical powders were examined to determine their flowability. Six combinations of Respitose® ML001, hydroxypropyl methylcellulose (HPMC), and an active pharmaceutical ingredient (API) in varying concentrations were selected for investigation. Powder flowability was measured using the Jenike shear test, the most widely accepted flowability standard in the industry. The Jenike flow indices of the ordered mixtures were indistinguishable from the Jenike flow index of pure Respitose® at the alpha = 0.1 level.<p>The fourth objective, to develop a novel flowability tester using electrical capacitance tomography to measure the dynamic angle of repose, was investigated at the same time as the effect of moisture content. It was determined that the results of the novel dynamic angle of repose tester did not correlate well with the Jenike shear test. More development is needed before the novel flowability tester is ready for industrial use. The Jenike shear cell remains the only acceptable flow test for complex flow behaviour.

In the pharmaceutical industry uniform flow of powders is one of the most important considerations in solid dosage manufacture. Improper feeding of powders from storage hoppers into dye-presses can lead to inconsistent product quality, causing economic and health impacts. Investigation into the properties affecting powder flow is crucial. There were four objectives of the current research: 1. To determine the effect of moisture on the flow (Jenike flow index, Hausner Ratio and Carr Index, static and dynamic angle of repose) of selected pharmaceutical powders. 2. To study the effect of particle shape and size on Jenike flow index for selected starch and pharmaceutical powders. 3. To determine the effect of mixture compositions on the Jenike flow index of ordered mixtures of selected pharmaceutical powders. 4. To develop a novel flowability tester based on electrical capacitance tomography (ECT) that measures the dynamic angle of repose of powders.<p>To address the first objective, to determine the effect of moisture content on the flow of four pharmaceutical powders; an active pharmaceutical ingredient (API), aspartame, hydroxypropyl methylcellulose (HPMC), and Respitose® ML001 were selected. The API and Respitose® powders were found to be nonhygroscopic and were tested at near zero moisture contents only (in this case 0.31% and 0.19% respectively). Aspartame was tested at moisture contents of 0%, 2%, 5% and 8% and HPMC at moisture contents of 0%, 2%, 5% and 10%. Powder flowability was measured using the Jenike shear index, the Hausner Ratio, the Carr Index and the static and dynamic angles of repose. The Jenike flow index of aspartame increased from 0.885 to 3.65 with an increase in moisture content, which was attributed to the formation of large, round agglomerates. The Jenike flow index of HPMC decreased from 3.28 to 2.65 with an increase in moisture content, which was attributed to the increasing strength of liquid bridges. The Jenike flow index was the only flowability indicator to capture this complex behaviour. <p>In order to address the second objective, five starches (cow cockle, barley, rye, rice and tapioca), as well as four pharmaceutical ingredients (an API, aspartame, HPMC, and Respitose® ML001), were characterised for size and shape, and then tested for flowability. Powder flowability was measured using the Jenike shear test, the most widely accepted flowability standard in the pharmaceutical industry. It was found that the Jenike flow index decreased linearly with decreasing aspect ratio and decreasing roundness for the powders investigated. It was also determined that particle shape had a greater impact on flowability than size for powders under 30 microns in diameter. <p>To address the third objective, ordered mixtures of pharmaceutical powders were examined to determine their flowability. Six combinations of Respitose® ML001, hydroxypropyl methylcellulose (HPMC), and an active pharmaceutical ingredient (API) in varying concentrations were selected for investigation. Powder flowability was measured using the Jenike shear test, the most widely accepted flowability standard in the industry. The Jenike flow indices of the ordered mixtures were indistinguishable from the Jenike flow index of pure Respitose® at the alpha = 0.1 level.<p>The fourth objective, to develop a novel flowability tester using electrical capacitance tomography to measure the dynamic angle of repose, was investigated at the same time as the effect of moisture content. It was determined that the results of the novel dynamic angle of repose tester did not correlate well with the Jenike shear test. More development is needed before the novel flowability tester is ready for industrial use. The Jenike shear cell remains the only acceptable flow test for complex flow behaviour.

The subject of this thesis is the measurement of flow properties of powder materials. The theoretical part deals with particulate substances in general and describes the basic principles of flow behavior of powder materials. In the theoretical part is a description of the Jenike Shear Tester and Ring Shear Tester. The following section summarizes the Standard Shear Testing Technique. Measurements were carried out on the new apparatus Laboratory of Chemical Engineering. The measurement was selected 5 samples of limestone Omyacarb ® from Omya CZ s.r.o. Individual samples varied in four different particle size distributions and one sample was surface-modified hydrophobic stearic acid. Tests were conducted at 3 levels of the preshear normal stress - 2.5 kPa, 5 kPa and 7.5 kPa. Distribution function of particle size in the material data sheets supplied by the manufacturer were verified using a laser particle size analyzer Sympatec Helos KR purchased in the Materials Research Centre at the Faculty of Chemistry at Brno University of Technology.

This thesis focuses on particular materials and their flow properties. Handling of powder materials has an impact on technologic processes like storage, transport or dosage. In pharmacy flow properties are used for tabletting process of pills. For a correctly designed technologic process it is necessary to know the flow behaviour of powder materials. Measuring is the best way to study flow properties. The most commonly used instrument for measuring flowability are described in this thesis. Two different devices (Jenike shear device and Freeman FT4) were used to perform the experiments for the comparison of results. The tested materials were particular materials used in pharmacy. To further expand upon the research and to represent the importance of flowability, enclose to this work is a report regarding the examination of pyrolysis coke analyse from MOL Slovnaft.

The theoretical part of the thesis focuses on the description of particulate materials and their mechanical behaviors with a focus on flow properties. Great emphasis is placed on measuring the shear properties using a Jenike shear machine, on the correct procedure for standardized measurement and evaluation using Mohr's circles. The theoretical part focuses on the characterization of particulate matter using a variety of methods available, such as visual, separation, sedimentation, surface methods and methods of scanning field and flow. The practical part is focused on the determination of flow characteristics and surface finishing of finely ground limestone Omyacarb VA with various grain sizes. The surface was modified using stearic acid and calcium stearate. Attention was paid to the influence of the concentration of surface-regulating substances on the flowability of the material. The flowability of commercially supplied material was compared with lab modified materials and the determination of the theoretical content of stearic acid or calcium stearate was accomplished. Shear properties were measured using the Jenike shear machine. The material was further tested by laser diffraction and SEM with EDS particle surface analysis and elemental surface mapping.