Development of Sm-153 Chitosan for Radiosynovectomy

Developing new radiosynovectomy agents is of great importance due to the aging of human populations around the world and increasing the incidence of inflammatory diseases. In this work, Sm-153 chitosan agent was developed for the first time in our country and preparation and quality control of the compound is described. Sm-153 chloride was obtained by thermal neutron flux (4-5 × 1013 n.cm-2.s-1) of natural Sm2O3 sample, dissolved in acidic media. 153Sm-samarium chloride (370 MBq) was used in preparation of 153Sm-chitosan complex followed by quality control using MeOH: H2O: acetic acid (4: 4: 2) as mobile phase. The complex stability and viscosity were checked in the final solution up to 2 days. The complex solution and 153Sm3+ (80 µCi/100 µl) were injected intra-articularly into male rat knee joint followed by scarification studies 6 d post injection. Sm-153 chitosan was prepared successfully with high radiochemical purity (>99%, ITLC) at room temperature after 10-30 min followed by autoclave sterilization. The complex was stable at room temperature and 37ºC up to 2 days. No significant leakage of dose from injection site and its distribution in organs were observed up to 6 days for 153Sm-chitosan. Approximately, more than 90% of injected dose remained in injection site after 6d. The complex is a dedicated agent for radiosynovectomy. The experience from this study would lead to the development of more sophisticated radiosynovectomy radiopharmaceutcals for human use in the country.