The research and development of various nanotechnology platforms have received notable attention in the field of drug delivery, including diagnostics and therapy. However, there are numerous hurdles hindering their clinical translation and one, among them, is related to instability under storage. When selection of components or process conditions cannot mitigate this issue, the removal of water is unavoidable. Two are the most common and popular techniques for the stabilization of nanocarriers: spray drying and lyophilization. The first is based on the evaporation of water from droplets created by an atomizer. The contact time between droplets and hot air is very short (a few seconds), which makes it possible to dehydrate thermosensitive materials. The second includes three steps: freezing of colloidal system, primary drying (sublimation) and secondary drying (desorption). Freezing is a key step determining the ice nucleation process and the morphology of the frozen materials. Primary drying removes most free water by sublimation, whereas secondary drying gets rid of the bound water and results in a low residual water content of the freeze-dried cakes. Nevertheless, due to the complexity of both techniques and thermal and mechanical stresses occurring upon drying, nanocarriers can be damaged. Hence, the choice of less-than-optimal composition of materials to be dried and critical process parameters, can result in failure in the final dried product.
In this context, the talk will analyze the impact on spray-drying and lyophilization of the stability of polymeric nanoparticles and liposomes keeping in mind that only the rational cooperation between the right operative parameters and optimal formulation needs to be built in attempt to preserve features of nanocarriers. In particular, the discussion of case studies will introduce possible solutions which could help the audience to solve some challenges in the design of a final dried dosage form.