Freeze-drying of suspended vials: a first step toward continuous manufacturing

The new paradigm of pharmaceutical industry is to move from batch to continuous processes in order to satisfy the stringent requirements of quality, safety and efficiency set by regulatory authorities and reduce production costs. In this perspective, freeze-drying needs to be completely rethought in order to be more integrated in the chain of production of drugs, more flexible to respond to variations in market needs and allowing the monitoring of product quality. The future of freeze-drying, as a downstream process, is therefore to move from batch to continuous. Over the past decades many ideas regarding continuous freeze-drying has been proposed, but none of them has been successfully applied. This work describes some of the drawbacks of batch freeze-drying and explains how these technical limits can solved by continuous technologies.