Quality-by-Control of continuous drug substance isolation: study on a novel unit for integrated filtration-drying

In the last decade, pharmaceutical manufacturing has been undergoing a modernization trend, promoted by the US Food and Drug Administration (FDA) with the Quality-by-Design (QbD) initiative. However, in most of the cases, the product quality is still controlled in open-loop, and pharmaceutical operation is carried out in the traditional batch mode, rather than continuously. In this work, we present a framework for closed-loop quality control of a novel continuous integrated filtration-drying unit. The unit addresses the current lack of technology for continuous drug substance isolation, which is the main bottleneck in end-to-end continuous pharmaceutical manufacturing. With the proposed closed-loop control framework, the product conformity is improved, showing how a Quality-by-Control (QbC) strategy can outperform earlier QbD approaches based on open-loop control.