Subvisible/submicron particles are considered the new frontier in the pharmaceutical and cosmetic fields as delivery system for active principle. Their size distribution, composition, internal structure and shape are fundamental physical characteristics required for the technological optimization of the final product. In fact, these properties can affect a lot of parameters, including bulk properties, product performance, processability, stability and appearance of the end product, dissolution, absorption rates, and content uniformity.

CLASSIZER™ ONE empowers the developments and quality controls of simple and mixes of subvisible/submicron devices for controlled drug release, where particle monodispersion, stability, and constant drug loading are required. EOS technology provides the chance to fully characterize biocompatible systems such as liposomes and polymeric particles in terms of

Concentration (particle number)
Particle composition
Particle structure (i.e. solid or core-shell)

The case of poly(lactic-co-glycolic acid) (PLGA) particles for drug delivery purpose

(in figure) Poly Lactic-co-glycolic acid (PLGA) is widely used in research and clinics thanks to its biodegrability and biocompatibility properties.
EOS technology was proven to be able to discriminate between PLGA NPs with different payloads and different structures. Quantitative information has been obtained also in terms of particles degradation which is fundamental when developing controlled release systems.






(in figure) CLASSIZER™ is able to discriminate size and refractive index distribution for PLGA nanoparticles with different internal structures and payloads. In fact, it discriminates between PLGA compact nanospheres, PLGA spheres loaded homogenously with curcumin and PLGA nanocapsules, with a core-shell structure, internally loaded with a model fluorescent protein. Thanks to EOS proprietary algorithms and specific data analysis, the sensibility of CLASSIZER™ allows to detect and discriminate minute changes both in the nanoparticle structure and composition. To note, the analysis can be run even if the refractive index is not precisely known a priori


(in figure) Degradation, aging and release kinetics studies can also be performed, in a more comprehensive way with respect to traditional techniques. In fact, SPES patented scattering scheme provides a better sensibility than traditional particle sizing method, such as dynamic and static light scattering. Moreover, the peculiar ability of CLASSIZER™ to collect two variables at the same time allows the study of particle degradation from a new point of view. As in the figure, after 24 hours of incubation in phosphate saline buffer, PLGA particles did not show differences in particle size distribution, but change in their refractive index distribution indicated that degradation process was actually started. This information was completely precluded for traditional light scattering methods of analysis.