scholarly journals Assessment of Abrasion-Induced Visual Defects in Twin Screw Wet Granulation Using Wall Friction Measurements

2022 ◽  
Vol 23 (1) ◽  
Author(s):  
Judith Menth ◽  
Martin Maus ◽  
Karl G. Wagner
Keyword(s):  
Friction Angle ◽  
Wall Friction ◽  
Wall Material ◽  
Process Window ◽  
Wet Granulation ◽  
Visual Defect ◽  
Defect Rate ◽  
Starting Point ◽  
Twin Screw ◽  
Friction Measurements

AbstractStarting point of the presented study were abrasion effects occurring during a twin screw wet granulation (TSG) process of a new chemical entity (NCE) formulation, resulting in gray spots on the final tablets. Several actions and systematic changes of equipment and process parameter settings of TSG process were conducted which reduced the visual defect rate of the tablets, i.e., gray spots on the surface, below the specification limit. To understand the rationale and mechanism behind these improvements, correlations of defect rates and wall friction measurements using a Schulze ring shear tester were evaluated. To check the suitability of the method, a broad range of wall materials as well as powder formulations at various moisture levels were investigated with regard to their wall friction angle. As differences in wall friction angle could be detected, further experiments were conducted using wall material samples made out of different screw materials for TSG. Evaluation of these screw wall material samples gave first hints, which screw materials should be preferred in regard of friction for TSG process. In the finally presented case study, wall friction measurements were performed using the above mentioned NCE formulation with known abrasion issues at TSG processing. The results confirmed that changes which led to a reduced visual defect rate of tablets correlated with a decreased wall friction angle. The results suggest wall friction measurements as a potent tool for equipment selection and establishment of a suitable process window prior to conducting TSG experiments. Graphical abstract

scholarly journals The Influence of Equipment Design and Process Parameters on Granule Breakage in a Semi-Continuous Fluid Bed Dryer after Continuous Twin-Screw Wet Granulation

Pharmaceutics ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 293
Author(s):  
Alexander Ryckaert ◽  
Michael Ghijs ◽  
Christoph Portier ◽  
Dejan Djuric ◽  
Adrian Funke ◽  
...  
Keyword(s):  
Process Development ◽  
Wet Granulation ◽  
Major Goal ◽  
Drying Time ◽  
Process Step ◽  
Manufacturing Line ◽  
Fluid Bed ◽  
Twin Screw ◽  
Filling Phase ◽  
Twin Screw Granulation

The drying unit of a continuous from-powder-to-tablet manufacturing line based on twin-screw granulation (TSG) is a crucial intermediate process step to achieve the desired tablet quality. Understanding the size reduction of pharmaceutical granules before, during, and after the fluid bed drying process is, however, still lacking. A first major goal was to investigate the breakage and attrition phenomena during transport of wet and dry granules, the filling phase, and drying phase on a ConsiGma-25 system (C25). Pneumatic transport of the wet granules after TSG towards the dryer induced extensive breakage, whereas the turbulent filling and drying phase of the drying cells caused rather moderate breakage and attrition. Subsequently, the dry transfer line was responsible for additional extensive breakage and attrition. The second major goal was to compare the influence of drying air temperature and drying time on granule size and moisture content for granules processed with a commercial-scale ConsiGma-25 system and with the R&D-scale ConsiGma-1 (C1) system. Generally, the granule quality obtained after drying with C1 was not predictive for the C25, making it challenging during process development with the C1 to obtain representative granules for the C25.

scholarly journals Evaluation of Binders in Twin-Screw Wet Granulation

Pharmaceutics ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 241
Author(s):  
Claudia Köster ◽  
Sebastian Pohl ◽  
Peter Kleinebudde
Keyword(s):  
Molecular Weight ◽  
Tensile Strength ◽  
Wet Granulation ◽  
Compression Pressure ◽  
Demineralized Water ◽  
Twin Screw

The binders povidone (Kollidon 30), copovidone (Kollidon VA64), hypromellose (Pharmacoat 606), and three types of hyprolose (HPC SSL-SFP, HPC SSL, and HPC SL-FP) were evaluated regarding their suitability in twin-screw wet granulation. Six mixtures of lactose and binder as well as lactose without binder were twin-screw granulated with demineralized water at different barrel fill levels and subsequently tableted. A screening run with HPC SSL determined the amount of water as an influential parameter for oversized agglomerates. Subsequent examination of different binders, especially Kollidon 30 and Kollidon VA64 resulted in large granules. All binders, except Pharmacoat 606, led to a reduction of fines compared to granulation without a binder. The molecular weight of applied hyproloses did not appear as influential. Tableting required an upstream sieving step to remove overlarge granules. Tableting was possible for all formulations at sufficient compression pressure. Most binders resulted in comparable tensile strengths, while Pharmacoat 606 led to lower and lactose without a binder to the lowest tensile strength. Tablets without a binder disintegrated easily, whereas binder containing tablets of sufficient tensile strength often nearly failed or failed the disintegration test. Especially tablets containing Pharmacoat 606 and HPC SL-FP disintegrated too slowly.

scholarly journals Identifying Critical Binder Attributes to Facilitate Binder Selection for Efficient Formulation Development in a Continuous Twin Screw Wet Granulation Process

Pharmaceutics ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 210
Author(s):  
Lise Vandevivere ◽  
Maxine Vangampelaere ◽  
Christoph Portier ◽  
Cedrine de Backere ◽  
Olaf Häusler ◽  
...  
Keyword(s):  
Dissolution Kinetics ◽  
Wet Granulation ◽  
Continuous Manufacturing ◽  
Formulation Development ◽  
Granulation Process ◽  
Low Viscosity ◽  
Twin Screw ◽  
Poorly Soluble ◽  
Selection For ◽  
The Impact

The suitability of pharmaceutical binders for continuous twin-screw wet granulation was investigated as the pharmaceutical industry is undergoing a switch from batch to continuous manufacturing. Binder selection for twin-screw wet granulation should rely on a scientific approach to enable efficient formulation development. Therefore, the current study identified binder attributes affecting the binder effectiveness in a wet granulation process of a highly soluble model excipient (mannitol). For this formulation, higher binder effectiveness was linked to fast activation of the binder properties (i.e., fast binder dissolution kinetics combined with low viscosity attributes and good wetting properties by the binder). As the impact of binder attributes on the granulation process of a poorly soluble formulation (dicalcium phosphate) was previously investigated, this enabled a comprehensive comparison between both formulations in current research focusing on binder selection. This comparison revealed that binder attributes that are important to guide binder selection differ in function of the solubility of the formulation. The identification of critical binder attributes in the current study enables rational and efficient binder selection for twin-screw granulation of well soluble and poorly soluble formulations. Binder addition proved especially valuable for a poorly soluble formulation.

Native starch as in situ binder for continuous twin screw wet granulation

2019 ◽  
Vol 571 ◽  
pp. 118760 ◽  
Author(s):  
Lise Vandevivere ◽  
Christoph Portier ◽  
Valérie Vanhoorne ◽  
Olaf Häusler ◽  
Denis Simon ◽  
...  
Keyword(s):  
Wet Granulation ◽  
Native Starch ◽  
Twin Screw

Formulation of Seismic Passive Resistance of Retaining Wall Backfilled with c-F Soil

2012 ◽  
Vol 3 (2) ◽  
pp. 15-24 ◽  
Author(s):  
Sima Ghosh
Keyword(s):  
Retaining Wall ◽  
Pressure Coefficient ◽  
Earth Pressure ◽  
Friction Angle ◽  
Wall Friction ◽  
Unit Weight ◽  
Passive Resistance ◽  
Angle Of Internal Friction ◽  
Variation Of Parameters ◽  
Wide Range

Knowledge of passive resistance is extremely important and it is the basic data required for the design of geotechnical structures like the retaining wall moving towards the backfill, the foundations, the anchors etc. An attempt is made to develop a formulation for the evolution of seismic passive resistance of a retaining wall supporting c-F backfill using pseudo-static method. Considering a planar rupture surface, the formulation is developed in such a way so that a single critical wedge surface is generated. The variation of seismic passive earth pressure coefficient are studied for wide range of variation of parameters like angle of internal friction, angle of wall friction, cohesion, adhesion, surcharge, unit weight of the backfill material, height and seismic coefficients.

Moisture Dependent Dynamic Flow Properties of Coconut Flours

2016 ◽  
Vol 12 (6) ◽  
pp. 577-585 ◽  
Author(s):  
M. R. Manikantan ◽  
R. P. Kingsly Ambrose ◽  
Sajid Alavi
Keyword(s):  
Moisture Content ◽  
Normal Stress ◽  
Flow Characteristics ◽  
Coconut Oil ◽  
Friction Angle ◽  
Wall Friction ◽  
Flow Properties ◽  
Dynamic Flow ◽  
Virgin Coconut Oil ◽  
Air Velocity

Abstract The dynamic flow properties of two important coproducts of virgin coconut oil (VCO) i. e. coconut milk residue flour (MRF) and VCO cake flour (CF) were studied. The basic flowability energy of CF was higher than MRF and increased with moisture content. The change in compressibility and shear stress, with applied normal stress and moisture content, indicated that these powders are highly cohesive. For both flours, the energy required to make the powder flow increased with moisture at all experimental air velocity. Moisture did not significantly influence the cohesion and unconfined yield strength of MRF, whereas for CF there was significant effect due to the presence of moisture. The wall friction angle of both the flours increased significantly with moisture and decreased with applied normal stress. The results from this study indicated that, both CF and MRF at around 4.00 % moisture content had better flow characteristics than at higher moisture levels.

Validation of Sound Source Simulation due to Offshore Pile Driving

2015 ◽  
Author(s):  
Katja Reimann ◽  
Juergen Grabe
Keyword(s):  
Wave Propagation ◽  
Sound Source ◽  
Friction Angle ◽  
Sound Level ◽  
Material Behavior ◽  
Wall Friction ◽  
Parameter Study ◽  
Pile Driving ◽  
Linear Elastic ◽  
Inelastic Material

The influence of wave propagation through the soil on hydro sound immission due to offshore pile driving bears a lot of uncertainties. In acoustic analyses of impact pile driving, the sound source description is essential for wave propagation models. The excited open-ended steel pile and the soil interact with each other. In numerical analyses the choice of the used material law for the soil should be well suited, because of the effect on the pile vibration. Prognoses often use the linear elastic approach for non-cohesive granular materials which does not represent the inelastic material behavior of the soil. On the basis of experimental data, a numerical model to simulate one blow of impact pile driving is validated. A parameter study of the wall friction angle between steel and sand is conducted to investigate the influence on the radiated hydro sound level under drained conditions.

TOWARD A GENERIC MODEL FOR TWIN-SCREW WET GRANULATION

2019 ◽  
pp. 173-185
Author(s):  
Daan Van Hauwermeiren ◽  
Michaël Ghijs ◽  
Ingmar Nopens ◽  
Maxim Verstraeten ◽  
Thomas De Beer ◽  
...  
Keyword(s):  
Generic Model ◽  
Wet Granulation ◽  
Twin Screw
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