[Preparation and physicochemical study of the preservation of nanoparticles]

The importance of nanoparticle formulation is increasingly recognized in supporting pharmaceutical development. Thus, maintaining nanoparticles in a constant state is a major issue. A method involving lyophilization with the addition of saccharides can be used to maintain the steady state of nanoparticles. In this study, trisaccharides, tetrasaccharides, and pentasaccharides were added to nanoparticle suspensions, followed by rehydration of the samples, which had been either dried normally or freeze-dried. The particle size after rehydration was measured. In addition, each powder was measured using a powder X-ray diffractometer and thermal analysis device to investigate the correlation between the nanoparticles' aggregation and the crystal form of saccharides. The diameter of the nanoparticles was maintained when it was freeze-dried, while particle aggregation occurred when normally dried samples were used. In addition, crystalline saccharide was not observed in the freeze-dried group, but did appear in the normally dried group.