Development of Sm-153 chitosan for radiosynovectomy

  Introduction: 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. Methods: 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. Results: 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. Conclusion: 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.