Publications by authors named "Daniel Puckhaber"

The majority of tablets manufactured contain lubricants to reduce friction during ejection. However, especially for plastically deforming materials, e.g.

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Introduction: Tablets are commonly produced by internally adding particulate lubricants, which are known to possibly lower the mechanical strength of tablets. This reduction is caused by the coverage of matrix forming components by lubricant particles, resulting in decreased interparticulate interactions. The known incompatibilities with some active compounds of the predominantly used lubricant, magnesium stearate, call for the in-depth characterization of alternative lubricants.

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Modeling of structural and mechanical tablet properties consisting of multiple components, based on a minimum of experimental data is of high interest, in order to minimize time- and cost-intensive experimental trials in the development of new tablet formulations. The majority of commonly available models use the compressibility and compactibility of constituent components and establish mixing rules between those components, in order to predict the tablet properties of formulations containing multiple components. However, their applicability is limited to single materials, which form intact tablets (e.

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In rotary tablet presses, the powder flow into the dies is typically facilitated by paddle feeder. For internally lubricated formulations, the shear forces exerted by the paddle rotation can result in a considerable decrease in tablet strength due to the dispersion of lubricant agglomerates. Available models to describe the lubricant dispersion in paddle feeder allow only a limited quantitative description and transferability of the process.

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The tableting of most pharmaceutical formulations requires the addition of lubricants to reduce ejection forces, prevent tooling damage and tablet defects. The internal addition of lubricants is known to reduce tablet tensile strength, especially of mainly plastically deforming materials. To date, available models show only limited quantitative predictive accuracy for the influence of lubricant concentration on the mechanical strength of tablets.

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Paddle feeders are devices commonly used in rotary tablet presses to facilitate constant and efficient die filling. Adversely, the shear stress applied by the rotating paddles is known to affect the bulk properties of the processed powder dependent on the residence time. This study focuses on the residence time distribution (RTD) of two commonly applied excipients (microcrystalline cellulose, MCC; dicalcium phosphate, DCP), which exhibit different flow properties inside rotary tablet presses.

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Compaction simulators are frequently used in the formulation and process development of tablets, bringing about the advantages of flexibility, low material consumption, and high instrumentation to generate the most possible process understanding. However, their capability of resembling general aspects of rotary press compaction and their precision in simulating or mimicking sub-processes such as feeding and filling need to be systematically studied. The effect of material deformation behavior, blend composition, and feeding on tensile strength and simulation precision as compared with rotary presses of different scales is evaluated in this study.

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