PTB News 1/2005 (135 kB) PTB News 1/2005, English edition, Issue May 2005In order to optimize the delivery of the active substances of a tablet you should know where and when the tablet dissolves. At PTB a new method has been developed to monitor the path of a tablet during dissolution in the gastrointestinal tract without subjecting the patient to additional stress. In cooperation with the international pharmaceutical company AstraZenecea various types of medication have now been tested for the first time.
The basic concept of the procedure is to mix magnetic powder particles in the tablet. These particles are readily used as colour pigments in foods. The tablet is subjected to a strong magnetic field to create a permanent magnetization of the particles in the pill. After the tablet is taken the state of dissolution of the pill is given by the strength of the permanent magnetic moment.
This process is monitored by the 63-channel SQUID-array that PTB operates for medical diagnostics in its laboratory at the Charité medical clinic in Berlin. The two-dimensional flat array is held at –269 °C in a helium Dewar in close distance above the abdomen of the volunteer. Position and strength of the magnetic moments are calculated from the measurement data with high precision and good time resolution. The method is contactless and without any health hazard. It is therefore suitable for mass surveys to obtain statistical statements on the dissolution behaviour of drugs in the human body.