(249g) Heat and Mass Transfer in a Pharmaceutical Coating Process
- Conference: AIChE Annual Meeting
- Year: 2020
- Proceeding: 2020 Virtual AIChE Annual Meeting
- Group: Pharmaceutical Discovery, Development and Manufacturing Forum
- Time: Tuesday, November 17, 2020 - 9:00am-9:15am
From former studies, it is known that small droplets, a diluted coating solution and low spray rate improve the coating layer homogeneity1. On the other hand, such a process is energy and time consuming. Low spray rates and small droplets promote spray drying (premature droplet drying, inhibits spray deposition on particles), reducing the process efficiency. Additionally, the coating quality increases with higher spray rates1,2. From product quality point of view, the spray rate is capped by the amount of spray drying on the lower boundary and by overwetting, which would lead to agglomerations, on the upper boundary. Therefore, investigating the heat and mass transfer inside the coating device can help to find optimal process parameters.
In our work, a fully integrated CFD-DEM environment is used to model the transport phenomena in a lab-scale Wurster coater. The commercial DEM code XPS is coupled to AVL-FIRE for the CFD simulation. State-of-the-art models for momentum, heat and mass transfer between continuous and discrete phase are integrated in a fully coupled manner3. Temperatures, vapor mass fractions and evaporation rates of a coating process with a multicomponent spray solution are calculated. The amount of spray drying is quantified and related to the input parameters of the process.
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