(33b) Process Development and Scale-up of an Enzyme Removal Strategy for Drug Substance Manufacturing

Biocatalytic transformations have become increasingly prevalent in the pharmaceutical industry enabling the highly selective and sustainable synthesis of active pharmaceutical ingredient (API) intermediates. However, the removal of these enzymes in downstream processing to ensure the isolation of high quality intermediates not only poses a challenge during development at benchtop scale but also can often be a bottleneck in the long term manufacturing process. Therefore, to ensure successful tech transfer to manufacturing, an in-depth understanding of process sensitivities and appropriate scale-up parameters is critical when evaluating the various methods of enzyme removal during process development.

This presentation will discuss the various enzyme removal strategies that were explored during the development and optimization of an enzymatic hydroxylation process to isolate a drug substance intermediate. The intermediate is typically recovered by extraction with an organic solvent from the aqueous system; however, the presence of denatured enzymes can often obscure the liquid-liquid interface. The enzymes can alternatively be filtered off with the addition of a filter aid but enzyme filtration can often be inefficient and difficult to predict upon scale-up without proper development. Benchtop experiments were performed to explore liquid-liquid extraction and depth filter cartridges as well as the filtration (with the addition of filter aid) of not only the enzyme itself but also both the enzyme and drug substance intermediate. After assessing a variety of metrics including process efficiency and isolated intermediate quality, filtration of the enzyme with the addition of a filter aid was found to be optimal for our system. This process was optimized at benchtop scale before it was transferred initially to the kilo-scale lab and then to the pilot plant. Additionally, a process fingerprint was collected with a fiber optic scale in the pilot plant to demonstrate the robustness of the enzyme removal approach developed.