Defining the Range of Calibration Burden: From Full Calibration to Calibration-Free

The expansion of spectroscopic process analytical technology (PAT) within the pharmaceutical industry requires chemometric models to enable spectral interpretation. However, calibration of chemometric models often require an intense time, material, and financial burden which may discourage PAT deployment. The advancement of modeling strategies that reduce this calibration burden necessitates consistent terminology for describing model inputs and overall calibration burden throughout chemometric literature. The goal of this article is to define levels of calibration burden by clarifying dataset classifications and model inputs during PAT method development. The scope of this work is specific to calibration of chemometric models incorporated in PAT methods. Harmonizing the language used in the field of chemometrics to describe calibration burden benefits both pharmaceutical manufacturers and regulatory agencies.