Influence of pellet aggregate populations on the variability of pellet filling into hard shell capsules: A comparison of experiment and computer simulation

Variations in pellet filling into hard shell capsules and other cavities are attributed to many factors including fluctuations in pellet size, shape polydispersity, presence of aggregates and electrostatic charge. The influence of pellet aggregation has not previously been investigated, and therefore modelling of the filling behaviour of pellet populations with different levels of twin, triplet and tetrahedral aggregates was evaluated in this study. Pellet/aggregate mixtures were also filled experimentally alongside simulation. The experimental and simulation results for fill weight variability showed that predictions of the trends and values of the percentage coefficient of weight variation (% CV) for mixtures containing twin aggregates up to a level of 20% (w/w) could be achieved. The filling behaviour for triplet and tetrahedral aggregates could not however be simulated effectively due to pellet segregation.