Abstract
This paper describes the development of microcapsules with high disintegration rate efficiency for drug delivery systems (DDS) using shock waves and the design of the microcapsules. The microcapsules, which include a gas bubble, are made by a micro-manipulation system, and it was found that the production possibility depends on the chemical composition of the microcapsule. To obtain the design index of the capsule structure and configuration, a bubble deformation process near a curved elastic wall, which was an experimental model of the microcapsule membrane, was observed and analyzed. The results show that disintegration efficiency depends on the capsule size and Young's modulus of the membrane. As for Young's modulus, the disintegration efficiency peak value was around 100 kPa under several conditions. The Young's modulus of the microcapsule membrane changed with chemical composition, and was determined by comparing the aspirating process of the capsule membrane with the results of finite element analysis. When the apparent Young's modulus of the membrane considering visco-elasticity is more than 250 kPa, microcapsules including gas bubbles can be produced. In this case, the capsule membrane's optimum elasticity for easy disintegration is 250 kPa when considering the above results. Therefore, it is necessary to design a microcapsule with a gas bubble to optimize elasticity for production and ensure high disintegration rate efficiency.
