Preparation and quality control of 32P-labeled albumin particles for internal radiotherapy

Resumo

The paper deals with the preparation and quality control of ³²P-labeled albumin particles used in therapy of inoperable solid tumors with remarkable vascularization. A process was developed for preparing ³²P-labeled albumin particles by combining biocompatible human serum albumin and [³²P]phosphoric acid salt. Factors affecting the process were investigated, and labeling conditions were optimized. The size distribution, shape, and radiochemical stability of particles were determined. The biodistribution of the particles was examined after intravenous injection in Wistar rats. The in vivo stability and distribution of the radioactive particles in mice were studied with different administration methods. Optical microscopic examinations revealed that the particles had a narrow size distribution (20–50 μm) after sterilization and dispersion in a mixture of normal saline and human serum albumin or in Tween 80 solution. The particles prepared had high radiochemical stability and 99% purity. Experiments on the distribution in animals showed that high radioactivity was accumulated in the lungs as a vascular tumor model.