Relative humidity and qualities of hygroscopic medications stored in different one-dose packaging papers

The one-dose package is useful for patients who are prescribed multiple medications. However, the one-dose packaging of hygroscopic medications is difficult because the quality of the medication is reduced by moisture absorption. Cellophane polyethylene laminating paper at 20 μm or 30 μm thickness and glassine papers are widely used for one-dose packaging. The basic characteristics, such as water permeability, of these packaging papers have been demonstrated by companies; however, the quality changes of hygroscopic medications stored in these packaging papers are poorly understood. In this study, we compared the relative humidity in packaging papers and the qualities of the stored hygroscopic medications among 20 μm and 30 μm thick cellophane polyethylene laminating paper and glassine paper. Glucobay® 50 mg, Magmitt® 330 mg, and Phosblock® 250 mg tablets were used as hygroscopic medications to be packaged and the relative humidity, weight change, and hardness of tablets were measured. The relative humidity decreased in the order of glassine paper, 20 μm thick cellophane polyethylene laminating paper, and 30 μm thick cellophane polyethylene laminating paper. Additionally, tablets inside the 30 μm thick cellophane polyethylene laminating paper gained the least weight. Therefore, tablets in a 30 μm thick polyethylene laminating paper absorb less moisture than those in other papers. However, the effect was less pronounced at high temperature, even if the relative humidity remained the same. We expect that the results will be used by hospitals and clinical pharmacies to understand the characteristics of packaging papers and ensure appropriate usage.