Provoking an end-to-end continuous direct compression line with raw materials prone to segregation

Continuous manufacturing of solid oral dosage forms is promising for increasing the efficiency and quality of pharmaceutical production and products. In this study a whole train continuous direct compression (CDC) line has been provoked using challenging formulations typically prone to segregation in batch powder processing. Industrial compositions including components with variable size, bulk density and cohesive nature were selected. An experimental design, including variables such as API/mannitol particle size, API amount, powder feed rate and mixer speed, enabled the output quality of the provoked process to be assessed. Contrary to previous studies, a broader range of finished tablet quality attributes were probed, including content, uniformity of content, tensile strength as well as release performance. Overall, the continuous direct compression line was found to be a capable and efficient manufacturing process for the challenging compositions studied and surprisingly tolerable to handle the materials susceptible to segregation in typical batch settings. As expected, and given the 'fixed' apparatus configuration used in this study, the particulate material properties were found to have the most significant impact on the finished tablet quality attributes. The results emphasize the importance for taking a holistic approach when developing the operational windows and the strategy for control, e.g. by integrating the appropriate material properties, the actual apparatus design, and the relevant formulation design. The CDC line's ability to handle cohesive materials also seem to be one of the key advantages, thus confirming the recent promising results from other continuous direct compression studies.