A model experiment to study swallowing of spherical and elongated particles

Abstract

Abstract. Swallowing disorders are not uncommon among elderly and people affected by neurological diseases. For these patients the ingestion of solid grains, such as pharmaceutical oral solid formulations, could result in choking. This generally results in a low compliance in taking solid medications. The effect of the solid medication size on the real or perceived ease of swallowing is still to be understood from the mechanistic viewpoint. The interplay of the inclusion shape and the rheology of the liquid being swallowed together with the medication is also not fully understood. In this study, a model experiment was developed to study the oropharyngeal phase of swallowing, replicating the dynamics of the bolus flow induced by the tongue (by means of a roller driven by an applied force). Experiments were performed using a wide set of solid inclusions, dispersed in a thick Newtonian liquid. Predictions for a simple theory are compared with experiments. Results show that an increase in the grain size results in a slower dynamics of the swallowing. Furthermore, the experiments demonstrated the paramount role of shape, as flatter and more streamlined inclusions flow faster than spherical. This approach can support the design of new oral solid formulations that can be ingested more easily and effectively also by people with mild swallowing disorders.

A review of the approaches to predict the ease of swallowing and post-swallow residues

“…A study for the oral phase of swallowing in presence of suspended particles, as to mimic swallowing of solid oral dosage forms, was also published (Marconati et al, 2017b). In a recent follow-up article the same authors compared also the in vitro results obtained with multiparticulate formulations with the results of 195 sensory tests (Marconati et al, 2018, Submitted).…”