Evaluation and comparison of physicomechanical characteristics of gelatin and hypromellose capsules

The aim of this study is evaluation and comparison of physical and mechanical properties of hypromellose and gelatin capsules. For this purpose, the empty and filled capsules of hypromellose and gelatin (size 4) were examined in regard with their physical and mechanical characteristics, employing textural analysis, and disintegration properties in various immersion fluids, utilizing a USP 28 disintegration apparatus. The results demonstrated that owing to their greater water permeability, gelatin capsules disintegrate much faster than hypromellose shells in all tested media. However, hypromellose capsules showed a more uniform pattern of dispersion in the disintegration fluids. As for mechanical properties, at ambient conditions, gelatin capsules appeared to be harder and stronger with less elasticity as compared with hypromellose shells. On the contrary, at an elevated temperature, gelatin capsules demonstrated lower resilience. This study shows that hypromellose capsules have excellent properties and are promising as far as regulatory, manufacturing, religious, and dietary issues are concerned.