The conversion of colloidal drug carriers/polymeric nanoparticles into dry microparticulate powders (e.g. by spray-drying) is a prominent approach to overcome the aerodynamic limitations of these formulations for delivery via inhalation. However, to what extent such nano-embedded microparticles disintegrate into individual/intact nanoparticles after contacting relevant physiological media has so far not been addressed. 

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