Moisture Protection for Powder Preparations ; Effect of Storage Conditions and the Quality of Wrapping Paper

The effect of storage condition and the quality of wrapping paper on the moisture protection of pharmaceutical preparations were investigated using a couple of pulverized hygroscopic pharmaceuticals and a few powder preparations having different critical relative humidity. Sodium valproate or potassium L-aspartate tablet was pulverized. Powder preparations used were potato starch, lactose, sodium chloride and fructose. 9 different wrapping papers having various grades of moisture permeability were adopted. The results of the study were as follows:1) The moisture permeation of wrapped powder preparations is affected by storage conditions. 2) Amount of absorbed moisture decreased when wrapping papers, with low moisture permeability were used; therefore, it became clear that the selection of suitable wrapping papers is important to protect powder preparations against the moisture permeation.