Evaluation of heat-conduction microcalorimetry in pharmaceutical stability studies. VI. Continuous monitoring of the interaction of water vapour with powders and powder mixtures at various relative humidities

Characteristics and Significance of the Amorphous State in Pharmaceutical Systems

“…The plasticizing effects of water vapor on amorphous pharmaceutical materials have been described in some detail 33,36,83 and can potentially induce unwanted effects such as spontaneous phase transitions and lyophile collapse. 42,91 Isothermal microcalorimetric techniques can be used in conjunction with water vapor sorption methods to study such phase transitions from the amorphous state. 91 The influence of additives on the kinetics of amorphous to crystalline phase transition in lactose have been investigated, 92 as has the physical stability of amorphous drugs.…”

“…42,91 Isothermal microcalorimetric techniques can be used in conjunction with water vapor sorption methods to study such phase transitions from the amorphous state. 91 The influence of additives on the kinetics of amorphous to crystalline phase transition in lactose have been investigated, 92 as has the physical stability of amorphous drugs. 93 Typically the amorphous content of a partially crystalline material can be quantified and the enthalpies of sorption and crystallization determined.…”

Scaling Up the Spray Drying Process from Pilot to Production Scale Using an Atomized Droplet Size Criterion

“…A reference ampoule without any sample was prepared accordingly. The salt solutions were prepared as described by Angberg et al (24). The ampoules were immediately transferred to the calorimeter, equilibrated at 25°C and placed in the equilibrium position.…”

Effects of Ethanol to Water Ratio in Feed Solution on the Crystallinity of Spray-Dried Lactose

“…The miniature humidity chamber technique [11,12] was employed to detect the thermal response for the recrystallization of amorphous lactose. The heat flow curves were monitored as a function of time.…”