2026 Volume 52 Issue 8 Pages 587-594
We investigated the impact of temperature and humidity on the convenience of handling over-the-counter (OTC) soft capsule drugs. Following a report of capsule rupture and liquid leakage in Product A, we performed controlled experiments using five products, including Product A. Capsules in the press-through packaging were stored under various conditions (20℃ or 35℃; high or low humidity) and evaluated for elongation rate under pressure, rupture rate, moisture absorption, and ease of removal from press-through packaging.
Product A was significantly susceptible to high temperature and humidity conditions; all capsules ruptured after 14 days at 35℃ and high humidity. Moisture absorption was 2.40％, which was significantly higher than that of all other products (0.53％ – 1.26％), except for Product D (3.23％). Deformation under 10 N pressure increased markedly for Product A (1.575-fold), whereas the other products showed minimal change. Sensory testing revealed a substantial decline in the ease of removal of Product A (0.75 points vs. 5.0 at baseline): 17 of 24 capsules leaked during handling.
In conclusion, a certain commercially available product is suggested to exhibit changes in physical properties and handling convenience. Because purchasers may store OTC drugs for a long time, establishing information that enables pharmacists or registered sellers of OTC drugs to provide appropriate advice is necessary.
