AN001-2021 Analysis of Polymeric Particles via SPES Technology
ABSTRACT: Submicron and micrometric polymeric particle dispersions are common in a multitude of applications and products such as pharmaceutical, personal care, food, ceramics, pigments, inks, and cements. A proper dispersion of the particles is necessary to avoid sedimentation, instability, or product failure due to aggregation, oversize, and aging. Bottom-up Quality-by-Design formulation, top-down Safe-by-Design approaches and product manufacturing require a reliable method to analyse the different particulate populations in all the intermediate formulation steps and in the final product. This operation must be achieved regardless of the complexity and heterogeneity of the sample. These complexities are due to the presence of particles with different optical properties, such as different refractive index, different internal structure (e.g., core-shell, mesoporous), different shape (e.g., rods, plates), and, finally, the presence of impurities or synthesis residues. The same considerations must be adopted when the formulation’s behaviour is studied, and thus optimised while analysing the particles directly in target fluids. In this case, the presence of other particles typically prevents a reliable and repeatable analysis via traditional approaches. The capabilities of Classizer™ ONE and SPES patented method of discriminating single particle basing on their optical properties is of capital importance with heterogeneous systems and when particle behaviour must be investigated in complex-but-real target media to tailor the product formulation and improve its effectiveness. SPES data provides physical and statistical information, as particle size distribution and numerical concentration, as well as insight on the particle structure and stability. Applications ranges from the estimation of the number of aggregates per mL respect to the choice of the surfactant, e.g. for the improvement of the wetting of a powder or of the shelf life of a product, to the study of the behaviour of particles in target heterogeneous media to tailor the their formulation. Oversize analysis can be performed also in presence of impurities. Scraps and out-of-specifics can be monitored in intermediates and final formulation.
