Compaction analysis and optimisation of convex-faced pharmaceutical tablets using numerical techniques

Abstract

Capping failure, edge chipping, and non-uniform mechanical properties of convexfaced pharmaceutical tablets are common problems in pharma industry. In this paper, Finite Element Modelling (FEM) and Design of Experiment (DoE) techniques are adopted to find the optimal shape of convex-faced (CF) pharmaceutical tablet which has more uniform mechanical properties and less capping and chipping tendency. The effects of the geometrical parameters and friction on the compaction responses of convex-faced pharmaceutical tablets were first identified and analysed. The finite element model of the tabletting process was generated using the implicit code (ABAQUS) and validated against experimental measurements. Response Surface Methodology (RSM) was employed to establish the relationship between the design variables, represented by the geometrical parameters and the friction coefficient, and compaction responses of interest including residual die pressure, the variation of relative density within the tablet, and the relative shear stress of the edge of the tablet. A statistical-based optimisation approach is then employed to undertake shape optimisation of CF tablets. The obtained results demonstrated how the geometrical parameters of CF tablet and the friction coefficient have significant effects on the compaction behaviour and quality of the pharmaceutical tablet.

Finite Element Analysis and Modeling in Pharmaceutical Tableting

“…Two studies (4.4% of the total) deal with the stress/strain distribution during the 3-point bending test [ 94 , 95 ]. The rest of the studies deal specifically with failure mechanisms (15.6%) [ 96 , 97 , 98 , 99 , 100 , 101 , 102 ], friction (11.1%) [ 4 , 28 , 103 , 104 , 105 ], temperature evolution (6.7%) [ 106 , 107 , 108 ], and viscoelastic behavior (6.7%) [ 29 , 109 , 110 ]. From the above account, it appears that FEA has been mostly implemented for the study of stress distribution during tablet formation by compression and during testing of various tablet shapes.…”

“…Baroutaji et al (2019) [ 96 ] studied the effects of geometrical parameters on the compression of convex-faced tablets by applying experimental design (DoE) and response surface methodology (RSM) to compression responses computed by FEA in order to optimize tableting. Relationships were established between the diameter and radius of curvature with the friction coefficient, residual die pressure, relative density variation, and relative shear stress.…”

“… Comparison of flat- and optimal convex-faced tablets: ( a ) relative density (RD) distribution, ( b ) shear stress distribution within the tablets as they eject from the die, and ( c ) plot of radial pressure vs. compaction pressure (Adapted with permission from Ref. [ 96 ]). …”

Deformation and energy absorption of additively manufactured functionally graded thickness thin-walled circular tubes under lateral crushing

“…This approach seeks the solution for the optimisation problem with multiple objectives by formulating a desirability function which combines all multiple responses into a single non-dimension objective function, thus converting the multi-objective optimisation problem into a single objective problem. This desirability function takes a value between 0 and 1 and the optimal solution is the one with the greatest desirability [4,53]. The crashworthiness multi-objective design optimisation framework is illustrated in Figure 10.…”

Additively manufactured AlSi10Mg inherently stable thin and thick-walled lattice with negative Poisson’s ratio

“…The equations were then extrapolated to identify relevant model terms based on how well the equation fits the experimental data. The stepwise regression was chosen as it eliminates the insignificant model terms automatically from the polynomial equation [173,174]. The statistical significance of the models and each term in the regression equation were evaluated using statistical measures that achieve the best fit [175].…”