Crystallizing amino acids as bulking agents in freeze-drying.

Bulking agents as mannitol (Man) and glycine (Gly) require high bulking agent to stabilizer ratios to ensure their crystallization during the freeze-drying process. The aim of this study was to investigate several amino acids (AA) as potential alternative bulking agents in low AA to sucrose (Suc) ratios. A fast freeze-drying process was performed above the collapse temperature (Tc) of the amorphous phase challenging the crystalline AA scaffold.