Issue link: https://www.e-digitaleditions.com/i/1499609
26 Pharmaceutical Technology ® Trends in Manufacturing eBook May 2023 PharmTech.com continuous manufacturing uous manufacturing, it is important to make sure that the feed tanks (F T) never r un out of feed ma- terials. As a result, timely refilling of the material to the feed tank becomes necessary. The developed model has been used to design and demonstrate the feed tank refill strategy. A refill response is shown in Figure 5. As shown in the figure, the feed tank has been refilled three times. It was obser ved that the fluid flow-rate entering the FT was active only during the refilling of the f luid as assigned by the control logic. The model was developed with the objective that the time taken for refilling of the feed tank is minimum, and the operational time of the feed tank rema i ns ma x imum. W hen t h is model was simu- lated for different inlet and outlet f low-rates, it was observed that the difference in both the f low rates should be at least 10 times to achieve the above-men- tioned objective. Once the inlet and outlet f low-rate are decided, the time taken for the refilling of the FT is fixed for every refill. The model is used to study the effects of through- put and material properties on the refill strategy. In Figure 6(a), the impact of change in the throughput on refill strategy is shown. At lower throughput, the refill frequency decreases. The mass holdup of the f luid inside the FT remains for a longer period be- tween two refills as the outlet fluid flowrate decreases. The impact of change in material property (bulk den- sit y) of the f luid on the refill strateg y is shown in Figure 6(b). As shown in the figure, as the density of the f luid increases, the refill frequency decreases. Also, on increasing the density of the f luid, the mass of the f luid inside the feed tank increases. Conclusion A model librar y has been developed t hat can be adapted for a variety of continuous API manufacturing processes to generate the different process configura- tions. The application of the model for scenario, sen- sitivity analysis, dynamic optimization, and design of suitable control architecture has been demonstrated. The model can be used for several other applications. Acknowledgements T his work is supported by FDA under contract number 75F40121C00106. References 1. Yu, L. Continuous Manufacturing Has a Strong Impact on Drug Quality. Pharmaceutical Processing World, April 13, 2016. 2. Reinhardt, I.C.; Oliveira, J.C.; Ring, D.T. Current Perspec t ives on t he Development of I ndu st r y 4.0 in the Pharmaceutical Sector. J. Ind. Inf. Integr. 2020, 18, 100131. 3. Singh, R.; Sahay, A.; Karry, K.M.; et al. Implemen- tation of a Hybrid MPC-PID Control Strategy Using PAT Tools into a Direct Compaction Continuous Pharmaceutical Tablet Manufacturing Pilot-Plant. Int. J. Pharm. 2014, 473 (1–2), 38–54.■ Advancements in the Implementation of Continuous Manufacturing In this episode of the Drug Digest Video Series, industry experts discuss the advantages and savings that continuous manufacturing may offer as well as the very real obstacles hindering full implementation. Drug Digest is a tech talk video series with the Pharmaceutical Technology ® editors, who interview industry experts to discuss the emerging opportunities, obstacles, and advances in the pharmaceutical and biopharmaceutical industry for the research, development, formulation, analysis, upstream and downstream processing, manufacturing, supply chain, and packaging of drug products. For more episodes, visit our website! Mauricio Futran, owner of Pharmaceutical Engineering Solutions Ravendra Singh, PhD, faculty, Department of Chemical and Biochemical Engineering, Rutgers University