Impacts of Compression on Crystallization Behavior of Freeze‐Dried Amorphous Sucrose

Influence of compression on water sorption, glass transition, and enthalpy relaxation behavior of freeze-dried amorphous sugar matrices

“…Namely, a freeze-dried sugar sample contains a large number of cylindrical pores that had been occupied by ice crystals and the pores serve as channels for the water vapor permeation. Compression substantially decreases the number of pores present in a sample (Imamura et al, 2010) and thus lowers the water diffusivity relative to that for an uncompressed sample. However, the remaining pores in the compressed sample results in the water diffusivity being higher than that for a nonporous sugar paste.…”

“…Our previous study demonstrated that the compression at hundreds of MPa markedly decreased the surface area of freezedried sugar samples (Imamura et al, 2010). Taking into account the fact that water sorption involves "adsorption" on the surface as well as "absorption" into the bulk, the decrease in water content as the result of the compression (Fig.…”

“…The T g values for the compressed and uncompressed amorphous sugar samples were determined using a Perkin-Elmer Pyris differential scanning calorimeter by the same procedure as used in our previous study (Imamura et al, 2010). In an typical experiment, 3-10 mg of a sample that had been hermetically sealed in 20 L aluminum pans was scanned at a rate of 10 • C/min from a temperature at least 50 • C lower than the T g to 180 • C, using an empty aluminum pan as a reference.…”

“…The physicochemical properties of an amorphous sugar matrix would also be expected to change, more or less, as the result of compression. In actual fact, the tendency for an amorphous sugar matrix to crystallize was reported to be increased by compression (Kawakami et al, 2006;Imamura et al, 2010) while the glass transition temperature (T g ) remained unchanged in the absolutely dried state (Imamura et al, 2010). However, substantially less information is available concerning the impact of compression on some of the physicochemical properties of amorphous sugar matrices.…”

Overcoming Poor Tabletability of Pharmaceutical Crystals by Surface Modification

“…Processes, such as milling, spray-drying, and compaction, may lead to phase change of organic solids (25)(26)(27)(28)(29). We therefore examine materials after both jetmilling and spray-drying to ensure phase stability of ACM.…”