High frequency controlled capsules with integrated gas producing cells.

In the present investigations, a new high frequency remote-controlled capsule has been developed in which the mechanical energy to empty a drug reservoir is generated by a miniature gas producing cell. If the poles of the gas producing cell are connected by an electric circuit, the gas production starts. The rate of gas production can be regulated by a resistor in the electric circuit and by the duration of activation of the system. To get a remote control, we developed a small receiver which is located inside the capsule. The receiver consists of an oscillating circuit, which is in resonance with an external 24 MHz high frequency transmitter. A MOSFET transistor acts as a switch in the electric circuit to start the gas production. Release experiments with oxprenolol show that different release patterns can be obtained.