Development of 177Lu-chitosan for radio-synovectomy

Introduction Chitosan (CHITO), is a natural, non-allergic and biodegradable polysaccharide with wide range applications in biopharmaceutics, agriculture and water treatment purposes and also RSV. In tis research the 177Lu-chitosan complex (177Lu-CHITO) was prepared successfully with high radiochemical purity (>99%) in diluted acetic acid solution. Methods: Lu-177 chloride was obtained by thermal neutron flux. 177Lu-CHITO complex was prepared and Radiochemical purity was determined using ITLC. Stability of 177Lu-CHITO was determined in presence of freshly prepared human serum (300 μl) and kept at 37 C for 2 days. The prepared complex solution (300 μCi/100 μl) was injected intra-articularly to rabbit knee joint. Leakage of injected dose from injection site and its distribution in the rabbit organs was investigated using SPECT imaging up to 2 days. Results: The 177Lu-CHITO complex was prepared with high radiochemical yield (>95 %) in the optimized condition; 35mg/3ml of chitosan concentration in diluted acetic acid solution (pH=3). The prepared complex was stable in the final solution at room temperature, 37oC and presence of human serum, and can be used even 24 hours after preparation. The retention in the injected rabbit knee joint was observed even after 48 hours post injection. Conclusion: A kit formulation was developed for the in-situ preparation of the radiopharmaceutical in remote clinical centers.