Abstract
Microneedle patches, which are attracting attention as a new administration route for drugs, are required to have reliable insertion properties in order to control the dosage. Therefore, research on dedicated applicator that uses a spring force to hit the application body site with a microneedle patch is also active. One of the major problems is that there is no test method to evaluate insertion property of microneedle patches simulating clinical conditions. In this study, we developed a test prototype applicator and dedicated measurement system in order to measure the compressive load transition generated when it hits an artificial material or a living body. In addition, we measured the mechanical properties of the skin and examined the relationship with the compressive load transition. As a result, it was found that the compressive load transition differs greatly depending on the applied body part. The tendency did not match the mechanical properties of the skin surface, suggesting that the structure of the subcutaneous tissue is also an important factor. In addition, by using a highly flexible material, it was possible to reproduce the compressive load transition similar to the case of hitting the living body. The results of this study will lead to the development of a test method to evaluate the insertion property of microneedle patches.
