Developing a continuous isolation process to produce; pure, dry, free flowing active pharmaceutical ingredient (API) is the final barrier to the implementation of continuous end to end pharmaceutical manufacturing. Recent work has led to the development of continuous filtration and washing prototypes for pharmaceutical process development and small scale manufacture. Here we address the challenge of static drying of solvent wet crystalline API in a fixed bed to facilitate the design of a continuous filter dryer for pharmaceutical development, without excessive particle breakage or formation of interparticle bridges leading to lump formation. We demonstrate the feasibility of drying small batches on a timescale suitable for continuous manufacturing, complemented by the development of a drying model that provides a design tool for process development. We also evaluate the impact of alternative washing and drying approaches on particle agglomeration. We conclude that our approach yields effective technology, with a performance that is amenable to predictive modelling.
- model validation