Abstract
A biodegradable PLA rod device (1mm in diameter x 3-4mm in length) has been developed for implantable drug delivery systems. Indometacin, an NSAID, incorporated in the PLA rod was released in a bi-phasic manner: the initial bursting due to surface drug dissolution and the second bursting caused by the polymer bulk erosion. The ultrasound (2W/cm2, 1MHz) was applied for 30 minutes following the onset of the drug release experiment. The ultrasonic energy significantly enhanced the drug release rate during the application period. After the removal of the ultrasonic energy, however, the enhanced drug release was not appeared and returned to the level under passive transport. This finding may suggest that the drug release rate from the PLA rod implant can be dynamically controlled by the ultrasound application.
