Implantable small device enabled with magnetic actuation for on-demand and pulsatile drug delivery.

We prepared an implantable device of small volume (SID) that is enabled with on-demand, pulsatile drug release. The device was designed to be actuated via a magnetic field; hence, there was no need for a battery. The device was actuated when the magnet was applied from the outside and infused the drug solution outward via the outlet ports in the device. When there was no external magnetic field, no drug was released. In this work, we varied the amount of delivered drug by varying the number of outlet ports. Thus, as the number of outlet ports increased from one to three, the average amount of drug release per actuation increased from 60.7 ± 1.79 μg to 122.6 ± 1.27 μg. In addition, when the SID with three outlet ports (SID3) was actuated once and thrice, the amount of drug release increased from 123.0 ± 6.99 μg to 357.3 ± 9.70 μg, respectively, which was reproducible over 30 days. When the SID3 was implanted in living animals for 30 days, plasma drug concentration was measured to be 92-146 ng ml-1 or 210-363 ng ml-1 when the device was actuated once or three consecutive times, respectively.