Effect of batch-to-batch variation of spray dried lactose on the performance of feeders

Abstract

With the emergence of quality by design (QbD), it becomes imperative to gain understanding of the impact of batch-to-batch variability of raw materials on the performance of processes. Feeding is the first unit of operation in a continuous manufacturing line and is critical for the final product quality. The performance of feeders defines the content of components that are fed into the system and therefore the composition that ends up in the formulation. In this paper, it is investigated how and to what extent variability of lactose can impact the feeding performance in different feeder set-ups. Spray dried lactose SuperTab 11SD was selected as a material, as it is one of the most widely used filler-binders for direct compression of tablets and can make up to 70% of the tablet content. For the first time, over 200 batches were evaluated regarding the impact of batch-to-batch variability upon feeding performance in volumetric mode. Results show that for an optimized feeder set-up with 22 mm double concave screws rotating at 342 rpm, the batch-to-batch variation was negligible compared to the natural feeding variability. However, for a stretched feeder set-up with 11 mm double concave screws rotating at 514 rpm, variability in material properties introduces additional variation in the obtained feed factor. Excipient variability and feeding set-up are therefore two factors to be considered when optimizing feeding consistency. • Impact of variability upon feeding performance was investigated for >200 batches. • The batch-to-batch variability is neglectable for an optimized feeder set-up. • Batch-to-batch variability can introduce variability in a stretched feeder set-up.