Prediction of segregation tendency in dry particulate pharmaceutical mixtures: Application of an adapted mathematical tool to cohesive and non-cohesive mixtures.
The measurement of average residence times and their variance, used to calculate the deviation of chemical reactors from the ideal behaviour of a perfectly-mixed vessel, or a plug flow pattern, has already been proposed in the literature to evaluate the segregation tendency of granular mixtures. The method consists of introducing pulse perturbation (of another material) to the established regular flow of a single granular material or a granular mixture and to assess the response of the system in terms of pulsed material concentration at the process outlet. The particles' average residence time and its standard deviation are then related to segregation tendency. Results from the application of this new method are useful when compared to those obtained from a reference mixture to be chosen according to a particular formulation development or process understanding need. This work applies the proposed method for various mixtures, both cohesive and non-cohesive, and derives phenomenological mathematical models expressing segregation tendency as a function of the parameters shown to be critical (i.e. statistically significant) to component segregation. The models were shown to be statistically and experimentally robust in the case of non-cohesive to slightly cohesive mixtures. Although the mathematical models are phenomenological, the findings allow for deriving mechanistic explanations on segregation tendency.
Abatzoglou
Nicolas
N
Department of Chemical and Biotechnological Engineering, Université de Sherbrooke, Sherbrooke, Québec, Canada. Nicolas.Abatzoglou@USherbrooke.ca
Simard
Jean-Sébastien
JS
D002626:Chemistry, Pharmaceutical / Q000379:methods; D005544:Forecasting; D008956:Models, Chemical; D004364:Pharmaceutical Preparations / Q000737:chemistry*; D011208:Powders
D004364:Pharmaceutical Preparations; D011208:Powders