Abrupt disintegration of highly porous particles in early stage dissolution

New insights into the disintegration mechanism and disintegration profiling of rapidly disintegrating tablets (RDTs) by thermal imaging

In current studies, the disintegration process of tablets has been studied by thermal imaging. The study covers two major aspects; first, new revelations in the mechanism of tablet disintegration, and second, the development of disintegration test as a multi-point test by new thermometric and non-thermometric methods. The study has been carried out on fexofenadine rapidly disintegrating tablets (FEX RDTs) in a dark room cabinet fitted with a Fluke thermal imager and using water as the disintegration medium. The studies exhibit the existence of endothermic peaks during the early penetration of water in FEX RDTs. These endotherms are prominent at the starting point when the disintegration has just started, or the tablet has been just exposed to the water. Such endotherms have not been reported earlier for tablets and can be considered as a part of the wicking mechanism during disintegration. In later stages, when the water has completely wet the tablet, the endotherms are superimposed by exotherms. The endotherms or exotherms have also been used as a measurement of disintegration in the form of a new thermometric parameter, "area under temperature curve" (AUTC). Non-thermometric disintegration profiling by residual and subtraction methods is also performed. Among these, disintegration by the residual method, i.e., disintegration (residual) is newly introduced. In the end, the principal component analysis (PCA) describes the relationship between various disintegration methods, particle size distribution, and dissolution. PCA reveals that AUTC is the best method for studying the disintegration behavior of FEX RDTs.

Development of Solid–Fluid Reaction Models—A Literature Review

A comprehensive review is carried out on the models and correlations for solid/fluid reactions that result from a complex multi-scale physicochemical process. A simulation of this process with CFD requires various complicated submodels and significant computational time, which often makes it undesirable and impractical in many industrial activities requiring a quick solution within a limited time frame, such as new product/process design, feasibility studies, and the evaluation or optimization of the existing processes, etc. In these circumstances, the existing models and correlations developed in the last few decades are of significant relevance and become a useful simulation tool. However, despite the increasing research interests in this area in the last thirty years, there is no comprehensive review available. This paper is thus motivated to review the models developed so far, as well as provide the selection guidance for model and correlations for the specific application to help engineers and researchers choose the most appropriate model for feasible solutions. Therefore, this review is also of practical relevance to professionals who need to perform engineering design or simulation work. The areas needing further development in solid–fluid reaction modelling are also identified and discussed.