Real-time control using process analytical technology (PAT) tools is required for the implementation of continuous crystallization within integrated continuous manufacturing (ICM) of pharmaceuticals. However, appropriate selection of PAT tools is challenging, and the design and operation of automated control loops for continuous crystallization within a continuous pharmaceutical process brings forward important questions. This paper discusses the process design and operation of a continuous reactive crystallization of aliskiren hemifumarate as part of an ICM pilot plant. Several PAT tools were used within automated control loops to satisfy specifications on the critical materials attributes of the crystallization process. The operational performance of the process was maintained for periods of time over 100 h. The purity of the targeted product exceeded 99%, and the process yield reached 91.4%.

A novel continuous heterogeneous crystallization process is developed in which the active pharmaceutical ingredient (API) is crystallized directly on the surface of an excipient within the crystallizer. The product is subsequently dried and formed into tablets without the need for complex downstream processing steps, such as milling, sieving, granulation, and blending. The aim is to eliminate many steps of the particle processing in drug product manufacturing. The APIs and excipients systems were selected by investigating heteroepitaxial mechanisms. The effects of various process parameters, such as temperature, residence time, and mode of operation, on drug loading were studied. Three different process designsmixed suspension mixed product removal with a traditional impeller, Viscojet mixing, and a fluidized bed crystallizerwere utilized for direct crystallization of the API on the surface of the crystalline excipient. The excipient selection and process design parameters have a significant impact on drug loading, avoidance of bulk nucleation and crystallization, control of API crystal shape and size, and process control. The maximum drug loading of the excipient with API in this study was 47%. Also, it was demonstrated that increasing the supersaturation ratio and residence time increased the drug loading. The products were collected from the crystallizer and directly compressed into tablet form. The tablet hardness and dissolution profile were also studied. The fully continuous process eliminates the downstream steps, resulting in the production of crystalline compounds and the final form (tablets) in a significantly faster, more efficient, and more economical manner with a smaller footprint. mentioned steps. 6−10 The precise final dosage, content uniformity, composition, mechanical properties, and critical quality attribute of every single tablet, which are highly regulated, 2,11−13 highly depend on the performance of the involved stages, for instance, component segregation, which can be caused by differences in particle size, density, or shape, and segregation in blending, hoppers, transfer lines, or feeders, and results in heterogeneity in tablet compositions. 14−17 Significant academic research and industrial development have been invested to overcome drug product line challenges and enable consistent manufacturing of high-quality tablets. 18−22 These challenges, and subsequent effects, are more problematic in the continuous manufacturing arena, 23,24 where the continuous flow of material, continuous workload of the drug product line, residence time distribution, and validation of "batches" of the final product enter into the design of already complicated processes. 17,20,21,23,24 Recent endeavors in shifting from the traditional batch pharmaceutical processes to the modern and emerging

Modular assembly line: a promising approach to reduce drug shortages, assure quality, and improve affordability.

Continuous manufacturing offers potential opportunities for the improved manufacturing of pharmaceutical products. A key challenge is the development of an appropriate control strategy.The experimental application of an automated control strategy is presented for an end-to-end continuous pharmaceutical pilot plant. The process starts from an advanced intermediate compound and finishes with the tablet formation steps. The focus of the experimental results is on the design and performance of the control loops needed to produce a slurry of an active pharmaceutical ingredient and a solvent with specified material properties. The results demonstrate that automated control can successfully keep critical material attributes close to desired set points for a sustained period of operation. This work aims to contribute to the

The pharmaceutical industry faces multiple challenges (e.g., inefficient manufacturing techniques, quality control issues, and supply chain vulnerabilities) because of its current batch-wise approach to manufacturing. Recent regulatory support for continuous manufacturing and advances in continuous process technologies have caused an increase in interest from some drug manufacturers to modernize their production processes. However, many of these companies have focused on hybrid processes, where only certain steps are continuous, while others remain batch. Herein, the quality by design (QbD)-based design strategy and operation of an end-to-end integrated continuous manufacturing (ICM) pilot plant that produces both small-molecule active pharmaceutical ingredient (API) and oral solid dosages (OSDs) are discussed. Additionally, important quality and economic matters pertaining to scale-up and commercialization are addressed. ICM has significant benefits, including better quality control, increased supply chain flexibility, a lower capital investment (in the example provided, a ∼ 90% reduction), and lower operating costs (in the example provided, a 33.6% reduction for API and 29.4% reduction for tablets).

The continuous reactive crystallization of an active pharmaceutical ingredient (API) in a plug flow reactor (PFR)-continuous stirred tank reactor (CSTR) cascade system with in-line PATs was developed and investigated. Residence...

Lower E-factor was obtained in an automated multi-stage continuous reactive-crystallization system.

Much less waste was generated by the end-to-end Integrated Continuous Manufacturing (ICM) process compared to the batch process.