How are unknown or foreign particles identified in pharmaceutical products?

Unknown or foreign particles are identified by analysing their size, shape, and chemical composition using microscopy, SEM-EDX, and FTIR to determine what the particle is and where it came from.

When a particle is found in a batch, identification follows a sequence: optical and electron microscopy describe size and morphology; SEM-EDX gives the elemental composition, identifying metals, glass, and other inorganics; and FTIR (and Raman) identify organics such as fibres, rubber, and polymers. Matching the result against the facility's contact and non-contact materials pinpoints the source --- for example, distinguishing stopper rubber from glove material, or vial glass from delaminated lamellae. This evidence supports the root-cause investigation, CAPA, and regulatory response.

FTI's particle characterization service performs this identification, and its plant-specific material library kits give investigators a pre-characterized reference set of every material in the facility, turning a slow investigation into a direct comparison. This post links to the contamination-source post (#9) and the particle-defects post (#1).