Although significant progress had been made in developing general scale-up rules for an aqueous pan-coating process, there are often scenarios where small-scale experiments are not found to be truly reflective of what may be observed at the large scale. This article reviews some of the methods traditionally used for scale-up, identifies the gaps associated with the traditional scale-up rules, and provides a perspective on a new real-time process monitoring tool that is capable of providing thermodynamic changes taking place in the microenvironment of the substrate being coated. This tool has been used to ensure increased success during scale-up by maintaining environmentally equivalent conditions between the processes, especially for systems that are sensitive to small thermodynamic changes.
Keywords: EEF factor; coating; microenvironment; process analytical technology (PAT); processing; quality by design (QbD); scale-up; solid dosage form; unit operations.
© 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.