無水乳糖錠の吸湿と膨張

抄録

The moisture sorption and volume expansion of anhydrous α- and β-lactose tablets were examined under various conditions of relative humidity. In the case of anhydrous α-lactose tablets, the moisture sorption and expansion of tablets occurred even at a relatively low humidity, leading to the formation of the α-monohydrate. The rate of moisture sorption and expansion increased with an increase in water vapor pressure and with a lowering in temperature. The effect of tablet thickness and of compaction pressure in tablet making were also examined using anhydrous α-lactose tablets. β-Lactose was less hygroscopic at below 90% relative humidity (R.H.). Moisture uptake was small and the expansion of tablets was not observed. When the water vapor pressure rose to almost saturation, β-lactose absorbed a large amount of moisture to form the α-monohydrate gradually.