The application of Process Analytical Technology (PAT) in pharmaceutical manufacture has gathered momentum over the last decade. Partly, driven by the advent of continuous manufacturing (CM). In this regard, good signal acquisition is of paramount importance when determining the capability and effectiveness of the PAT. This this is of particular importance when utilizing fiber optic probes for spectral collection. The analytical measurements for solid dosage manufacturing are typically more challenging due to the inhomogeneity associated with the pharmaceutical powder blends.
Different physical and chemical properties of powder such as size, shape, density, compressibility, moisture and API content, can be characterized in continuous mode via spectroscopic techniques using fiber optic probes. Despite the wide applicability of these techniques depends on appropriate design of the probe/sample interface for effective analysis. In the case of very dispersed powders, for example the particulate cloud seen in the picture above at the end of a milling step, or in a fluidized bed during granulation or drying operations, mechanical sampling becomes essential for diffuse reflectance probes to function correctly.