Defining Excipient Criticality

All excipients are indispensable in a formulation, but not all of them are crucial to the design or performance of the finished product. The current approach used by pharmaceutical manufacturers to classify process parameters and quality attributes as being critical or non-critical is too simplistic to adequately reflect current science- and risk-based approaches to product quality, noted Brian Carlin, director, Open Innovation at FMC, and a CPhI expert panel, in the 2016 CPhI Annual Industry Report.

In the report, Carlin explained that all excipients are potentially critical, especially when subject to cumulative changes throughout the product lifecycle. Simply classifying excipients as critical and non-critical can lead to inconsistencies. According to him, continuous monitoring of the impact from all excipients throughout the product lifecycle is more important than this one-off arbitrary binary classification during development.

Carlin pointed out that excipient risk cannot be fully assessed during development, as product and process changes, for example during scale-up, have the propensity to change the risk profile. It is, therefore, crucial to assess all attributes and parameters for impact, and to re-evaluate them again as new information becomes available.

Source: CPhI Annual Industry Report 2016