Studies on Moisture Protection for Powder Preparations : Effect of Heating Plate Temperature in Automatic Packaging Processes on Moisture Permeation

Abstract

The effect of heating plate temperature for automatic sealing of wrapping paper on moisture protection of powder preparations was investigated. Powder preparations used were pulverized sodium valproate tablet, lactose monohydrate, potato starch, D-glucose, sodium chloride, fructose and potassium iodide, and these had different critical relative humidities. Five wrapping papers having various moisture permeabilities were also used. It was revealed that (1) heating plate temperature played an important role for moisture protection of pharmaceuticals ; (2) moisture permeation may be derived through sealed area due to incomplete sealing at low temperatures (<100°C) and also through sealed edge due to melting of laminated polyethylene at high temperatures (150°C<); (3) suitable selection of the temperature is necessary to minimize moisture permeation and to protect powder preparation from hygroscopicity.