"Label and go"--a fast and easy radiolabelling method for pellets.

For the development and process optimization of pharmaceutical equipment, it is important to investigate the underlying processes. Taking the fluidized bed technology as an example, the study of particle flow pattern and convection of the particles within the functional unity is essential for construction and process improvement. With positron emission particle tracking (PEPT) it is possible to study the real-time particle motion with radiolabelled particles. We established a fast and simple labelling technique with [(18)F]fluoride for pellets composed of Avicel and anion exchange resin. The uptake of activity ranged from 1.3% to 1.7% per mg and 8.6% to 16.3% per pellet. A specific binding of [(18)F]fluoride with increasing degree of anion exchange resin in the pellets could be observed.