Process understanding of drying applied to wet granulation in single-pot equipment

The drying phase in single pot wet granulator-vacuum dryers has not been greatly investigated, however, this step is very important from an industrial manufacturing point of view expecially in terms of energy and time. According to the latest FDA guidance about Process Analytical Technologies (PAT), the most appropriate approach for optimizing pharmaceutical production involves process understanding. The aim of this study was the process understanding of drying in a single pot granulator (Rotocube 60, IMA). In particular, the effect of three drying parameters (bowl temperature, vacuum and microwaves) on the granule characteristics (loss on drying, morphology, particle size, flowability and friability) of a placebo product (monohydrate lactose, corn starch and polyvinylpirrolydone as binder) was evaluated. The properties of the related tablets (uniformity of mass, crushing strength, friability, disintegration time) were also studied. The preliminary data obtained, using the above mentioned equipment and formulation, suggest that different drying conditions, which determine different drying times, do not significantly affect the technological characteristics of both granules and tablets. In conclusion, this result demonstrates a clear formulation robustness, giving the opportunity to find the shortest drying time pertinent to drying conditions once the process is scaled up to an industrial single pot granulator.