[Remote controlled drug release in the alimentary tract by local power deposition in alternating magnetic fields]

Remote controlled release of agents in the alimentary tract is an important task of gastroenterology and pharmacy. We investigated two different methods of drug release by heating locally restricted parts in medical capsules: hysteresis losses of magnetite powder and eddy current losses of metals in alternating magnetic fields. The comparison of our experimental results with theoretically derived expectations show that both methods are suitable techniques if special technical conditions are met. In order to demonstrate the feasibility of simple constructions, we used a gelatin capsule, consisting of two parts which were kept together by a belt of wax and a small copper coil. This capsule was placed in water and the belt was heated in an alternating magnetic field until melting and releasing a test fluid after about 60 s.