Abstract
It is necessary to control of absorption time of drug capsule made of bio-absorbable material in drug delivery system (DDS), in order to release the drug concentrated at an affected part. Drug capsule with non-uniform thickness is useful to control the absorption time because capsule break and drug release occur at a thinnest part of the capsule. Mechanical stress occurred in bio-absorbable material also affect to its absorption ratio, so it is possible to control the absorption time by varying residual stress value if residual stress is given for the drug capsule of DDS. We investigated effect of the non-uniform shape and residual stress to the absorption time in two-dimensional ring made of bio-absorbable material. Variable cross-sectional ring with residual stress was made of PLLA, and absorption examination was carried out in HCOOH solution. From the results, possibility of control absorption time of drug capsule in DDS was considered.
