How integrated capabilities accelerate flow chemistry scale-up
Dr Jean-François Carniaux, VP and global API technical lead, and Dr Narendra Ambhaikar, regional head of R & D for India, at Piramal Pharma Solutions, weigh up some of the benefits of flow chemistry against batch
Flow chemistry has proven benefits. Compared to batch processing, it is faster, safer and more sustainable— advantages that have made the technique an established part of drug development. However, few companies are equipped to fully realise the benefits. To maximise the impact of flow chemistry, companies need the infrastructure and expertise to scale-up production seamlessly as a programme moves out of the lab and into production.
The emergence of flow chemistry as a preferred option for some synthesis projects makes it critical that drug innovators understand the keys to success, both at the start of a programme and as they scale up production. In this paper, we look at the factors to consider when evaluating whether to use a batch or flow reaction and discuss a case study that shows the value of integrated capabilities.
Where flow beats batch
Batch processing entails mixing known amounts of reagents and solvents, exposing the entire lot to the reaction conditions for a set amount of time and then terminating the synthesis. While it is a well-established approach to chemical synthesis, scale-up and instability can be points of concern. Batch reactors are the best choice for very slow reactions that are hard to accelerate through heating, but flow chemistry has advantages in other situations, such as where reaction mixtures are unstable.
Flow chemistry entails continuously pumping reactants through flow channels to the reactor to create a stream of product. Since the reagents are allowed to react stoichiometrically, flow can handle
46 SPECIALITY CHEMICALS MAGAZINE ESTABLISHED 1981