Pauli, Victoria Isabell, Elbaz, Frantz, Kleinebudde, Peter and Krumme, Markus (2019) Orthogonal redundant monitoring of a new continuous fluid bed dryer for pharmaceutical processing by means of mass and energy balance calculations and spectroscopic techniques. Journal of Pharmaceutical Sciences.

Abstract

In line with the ongoing shift from batch- to continuous pharmaceutical production of solid oral dosage forms, a novel continuous fluid bed drying system was developed. The forced-feed nature of the Glatt GPCG2 CM fluid bed dryer allows continuous, first-in-first-out drying of wet granulate materials based on its compartmentalized, rotating fluidizing chamber. The design ensures a narrow residence time distribution with limited risk of carryover from one compartment to the adjacent ones. Drying efficiency can be adapted through temperature, air flow and especially dryer rotation speed, a process parameter that is unique to the described system and allows fast and accurate process control.
The presented work aims to introduce the dryer’s functionalities in detail, and to demonstrate that the compartmentalized, rotating fluid bed chambers facilitates a stable, continuous drying behavior, which in turn ensures robust and repeatable residual moisture contents (loss-in-drying; LOD) of the discharged granules. Furthermore, a thorough mass- and energy balance (MEB) for the prediction of granules LOD is derived, based on the constantly logged process values provided by the granulating and drying unit. The resulting formulas are applied to two independent test-experiments, in order to demonstrate that precise LOD prediction in real-time is achievable by MEB as an orthogonal PAT method to common Near Infrared Spectroscopy (NIRS). On average, MEB results differed by 0.36 % LOD (absolute) from offline reference analyses, and by 0.61 % LOD from predictions made with an in-house available NIRS method. Furthermore, a good correlation between the observed (based on inlet- and exhaust air temperature measurements) and the expected thermal energy loss (caused by evaporation) in the dryer was found. Since the derived MEB is solely based on physical principles, it is product independent and can be transferred to any other material to be processed on the described equipment.

Item Type:	Article
Date Deposited:	28 Feb 2019 00:45
Last Modified:	28 Feb 2019 00:45
URI:	https://oak.novartis.com/id/eprint/37043