Solid phase extraction : An alternative to the use of rotary evaporators for solvent removal in the rapid formulation of PET radiopharmaceuticals

Solid phase extraction (SPE) was used for the formulation of several radiopharmaceuticals. The method involves dilution of the previously purified HPLC compound with water, trapping of the activity on an SPE bed, washing off the support, elution of the radiopharmaceutical with a small volume of ethanol (<1 mL) and dilution with sterile isotonic saline solution. Recovery of the radiopharmaceuticals was always higher than 97%. Two different methods of automation were developed for the formulation of [11C] and [18F]radiopharmaceuticals. In all cases, organic solvent levels in the injectable solution were below the recommended limits. This fast (3–6 min.) and easy to automate process can be considered as an alternative to the conventional methods (rotary evaporators). Copyright © 1999 John Wiley & Sons, Ltd.