U.S. Food and Drug Administration Issues NIR Guidance
On August 6, 2021, the U.S. Food and Drug Administration (FDA) released final guidance regarding near-infrared (NIR) analytical procedures. The guidance applies to new drug applications (NDAs), abbreviated new drug applications (ANDAs), and supplemental NDAs and ANDAs for small-molecule drugs. The FDA will address recommendations for NIR methods used in biologics under a future revision of the guidance.
The new guidance provides the agency’s recommendations for the development, validation, and use of NIR-based analytical procedures in evaluating a drug product’s identity, strength, quality, purity, and potency. The recommendations address the application of concepts described in FDA and International Council for Harmonization guidelines to NIR analytical procedures that use chemometric models. It also discusses submitting NIR documentation in applications.
The guidance does not discuss the development and validation of NIR analytical procedures or the setup, qualification, maintenance, or calibration of NIR instruments. The concepts of the guidance can be applied to other analytical technologies.
Scientists Unveil Better Mixing Rule for Absorption Spectroscopy of Aerosols and Colloids
June 16th 2025Researchers have introduced a simple yet powerful new rule based on Rayleigh scattering theory that accurately links the absorption behavior of composite media, like aerosols or colloids, to the properties of their nanoparticle constituents.
Short Tutorial: Complex-Valued Chemometrics for Composition Analysis
June 16th 2025In this tutorial, Thomas G. Mayerhöfer and Jürgen Popp introduce complex-valued chemometrics as a more physically grounded alternative to traditional intensity-based spectroscopy measurement methods. By incorporating both the real and imaginary parts of the complex refractive index of a sample, this approach preserves phase information and improves linearity with sample analyte concentration. The result is more robust and interpretable multivariate models, especially in systems affected by nonlinear effects or strong solvent and analyte interactions.
