QDIS Blog

Coming from the process development side of the pharmaceutical industry I’m always interested in being able to efficiently model a process from the small scale to the large scale. A recent paper describes the researchers experience with scaling the drying process from a 200 g scale in a rotary evaporator (yes, than can be used for drying solids as well as stripping solvent) to a 1000 kg scale in three different types of driers.

Modeling the Scale-Up of Contact Drying Processes: Org. Process Res. Dev., 10 (3), 409 -416, 2006.

It should be noted that the model is not universal; only 5 of the 8 systems investigated worked. It also should be pointed out that there is still quite a bit of unpredictability. If, during the evaporation, the material forms one large lump (not an uncommon occurrence) then the model doesn’t work. The two other cases that failed were also due to aggregation during the drying process. While this aggregation can be reduced by reducing the rotation speed, this also slows down the drying process and resulted in longer drying times.

While this paper outlines a useful approach, processes such as drying still depend very much on the product itself.

Technorati Tags: process development

Email Ed Vawter

Bookmark it with: | del.icio.us | Digg it | Furl | Simpy | Spurl | My Yahoo! |