In-die compression analysis is an effective method for the characterization of powder compressibility. However, physically unreasonable apparent solid fractions above one or apparent in-die porosities below zero are often calculated for higher compression stresses. One important reason for this is the neglect of solid compressibility and hence the assumption of a constant solid density. In this work, the solid compressibility of four pharmaceutical powders with different deformation behaviour is characterized using mercury porosimetry.

Mechanical strength is an important property for pharmaceutical tablets. Its study using the theory of linear elastic fracture mechanics has been introduced in the pharmaceutical field through the Brittle Fracture Index (BFI). This index is based on the stress concentration factor (SCF) and contradictory results have been published in the pharmaceutical literature about the value of the SCF during the diametral compression of a disc with a hole.

Finishing and transport operations of pharmaceutical tablets such as coating and conveying processes can qualitatively be improved with a better understanding of the interplay of process parameters and product quality attributes. This study provides a first step towards the simulation of these processes with the calibration of the motion modelling of uniaxial-compressed cylindrical tablets using the multi-sphere approach (MS) within the Discrete Element Method (DEM). Only high accuracy in the representation of cylindrical tablet shape, especially regarding edges, yields a good agreement between simulated and experimental packing fraction.

Numerical simulation with finite element method is commonly used to model the process of die compaction. In pharmaceutical field, the Drucker-Prager/Cap (DPC) model is by far the most used to study the mechanical behavior of the powder. Another classical model but less used model, the modified Cam-Clay (MC-C) model, is introduced in this study. The main advantage is that the model parameters are easier to determine for MC-C model than for DPC model.

The bilayer tableting technology is gaining more acceptance in the drug industry, due to its ability to improve the drug delivery strategies. It is currently assessed by the European Pharmacopoeia, that the mechanical strength of tablets can be evaluated using a diametral breaking tester. This device applies a force diametrically, and records the tablet breaking point. This approach has been used to measure the structural integrity of single layer tablets as well as bilayer (and multi-layer) tablets.

Although, adhesion at the interface of bilayer tablets is critical for their design it is difficult to characterize this adhesion between layers. In view of this, a new test with an easy implementation was proposed for the characterization of the interface of bilayer tablets. This work is presented as a proof-of-concept study to investigate the reliability of this new test with regard to the effects of some critical process parameters (e.g., compaction pressure applied on each layer) and material attributes (e.g., elasticity of the layered materials) on the interfacial adhesion of bilayer tablets.

Tablet final properties are mainly determined during the compaction process by the evolution of the stresses applied to the powder. Any process or product parameter that may influence this stress evolution may have a direct impact on the tablet final properties. In this article, we studied the influence of the friction between the tooling and the powder on the evolution of the die-wall pressure during compaction using flat and concave punches.

Bilayer tablets are of special interest in the pharmaceutical industry. The main problem during their manufacturing is the occurrence of delamination during or after the ejection from the die. This work studies the influence of using punches with a curvature on the interfacial strength and thus on the delamination tendency of bilayer tablets. Bilayer tablets were produced with a compaction simulator using different flat and concave punches with different radii of curvature.

Capping is a classical manufacturing problem for tablets, which is known to affect more biconvex tablets than flat-faced ones. One reason could be the development of a higher residual die-wall pressure during unloading. Unfortunately, contradictory results were published on the subject. In this work, the evolution of the die-wall pressure during the compaction of biconvex tablets was studied experimentally and using finite element method (FEM) modeling.

This work studies the influence of visco-elastic behavior in the finite element method (FEM) modeling of die compaction of pharmaceutical products and how such a viscoelastic behavior may improve the agreement between experimental and simulated compression curves. The modeling of the process was conducted on a pharmaceutical excipient, microcrystalline cellulose (MCC), by using Drucker–Prager cap model coupled with creep behavior in Abaqus® software.

Influence of the compaction speed on the final tablet properties is an important challenge during the scale-up of a solid dosage form. This strain rate sensitivity is generally attributed to the time dependent deformation behavior of the powder. In this work, we studied the influence of the speed on another important factor during compaction: friction between the tablet/powder and the die.

The elastic properties of pharmaceutical powders and compacts are of great interest to understand the complex phenomena that occur during and after the tableting process. The elastic recovery after compression is known to be linked with adverse phenomena such as capping or delamination of tablets. Classically, the elastic behavior is modeled using linear elasticity and is characterized using only Young's modulus (E), often by using a value extrapolated at zero porosity.

This study evaluated differences in rotary tablet presses quantitatively using a compaction simulator. First, we calculated the compaction velocity for each rotary tablet press. As a result, rotary tablet press B showed higher compaction velocity than rotary tablet press A regardless of having the same compaction conditions. It was also confirmed that the compaction velocity was changed depending on the rotation speed.

The effect of the elasticity of various pharmaceutical materials on the interfacial adhesion in bilayer tablets was investigated. The elastic properties of five pharmaceutical products were characterized by their total elastic recovery. To test the interfacial strength of the bilayer tablets a new flexural test was proposed. Thanks to the test configuration, the experimental breaking force is directly correlated with the interfacial layer strength.

Capping is a classical manufacturing problem for tablets, which is known to affect more biconvex tablets than flat-faced ones. One reason could be the development of a higher residual die-wall pressure during unloading. Unfortunately, contradictory results were published on the subject. In this work, the evolution of the die-wall pressure during the compaction of biconvex tablets was studied experimentally and using finite element method (FEM) modeling.

Roll compaction/dry granulation (RC/DG) is a widely used method in pharmaceutical industry. Nevertheless, in R&D problems can occur because it is a time and material consuming process. In previous trials it was shown that hybrid modeling of RC with the Styl’One Evolution can identify the settings to obtain ribbons with the desired solid fractions(SF).

This study focuses on improving the manufacturing process for a generic immediaterelease tablet containing erlotinib hydrochloride by adding a fines recycling process during roller compaction. Due to the large fraction of small-sized API particles, the starting powder mixture was inconsistently fed into the roller compactor. Consequently, poorly flowing granules with a high ratio of fines were produced. A fines recycling step was, therefore, added to the existing roller compaction process to minimize the risks caused by the poor granule flow.

On a roll compactor (RC), the space between the rolls is divided into a slip, a compaction and a release zone. The angle between the beginning and the end of the compaction zone is called nip angle. This angle is an important parameter for the process understanding. There are several approaches to determine the nip angle but they are laborious and difficult. The aim of this study was to use a uniaxial compaction simulator (Styl‘One Evolution, MEDELPHARM) for the nip angle estimation and to evaluate the influence of the specific compaction force, gap width and roll speed on the nip angle of different excipients.

The impact of the force feeder on tablet tensile strength depends on the amount of lubricant, the compaction behavior of the material (deformation vs. fragmentation) and the rotation speed of the feeder. This can be easily and quickly evaluated on a Styl’One™ using only small amounts of powder early in R&D stages, ensuring appropriate tablet properties during scale-up.

AIMS: Development of TIC devices Elaboration of the potential of the TIC design for drug release modification In-silico simulation of TIC drug release