Chakravarty Rubel, Pandey Usha, Manolkar Remani B, Dash Ashutosh, Venkatesh Meera, Pillai M R Ambikalmajan
Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Mumbai-400085, India.
Nucl Med Biol. 2008 Feb;35(2):245-53. doi: 10.1016/j.nucmedbio.2007.10.009.
90 Y of high specific activity and very high radionuclidic purity (>99.998%) is essential for targeted therapy. Since the current methods used for the preparation of 90 Y from 90 Sr are not adaptable for use in a central/hospital radiopharmacy, a simple 90 Sr-90 Y generator system based on electrochemical separation technique was developed.
Two-cycle electrolysis procedure was developed for separation of 90 Y from 90 Sr in nitrate solution. The first electrolysis was performed for 90 min in 90 Sr(NO3)2 feed solution at pH 2-3 at a potential of -2.5 V with 100-200 mA current using platinum electrodes. The second electrolysis was performed for 45 min in 3 mM HNO3 at a potential of -2.5 V with 100 mA current. In this step, the cathode from the first electrolysis containing 90 Y was used as anode along with a fresh circular platinum electrode as cathode. The 90 Y deposited on the circular cathode after the second electrolysis was dissolved in acetate buffer to obtain 90 Y acetate, suitable for radiolabeling.
96% recovery of 90 Y could be achieved in each cycle, with an overall decay corrected yield of >90%. The recovered 90 Y had high radionuclidic purity with barely 30.2+/-15.2 kBq (817+/-411 nCi) of 90 Sr per 37 GBq (1 Ci) of 90 Y (0.817+/-0.411 ppm). Consistent and repeated separation could be demonstrated using up to 1.85 GBq (50 mCi) of 90 Sr. The generator was named "Kamadhenu," the eternally milk-yielding Indian mythological cow.
A technique suitable for adaptation at central radiopharmacies for obtaining therapeutic quantities of pure 90 Y has been developed.
高比活度且放射性核素纯度极高（>99.998%）的钇-90对于靶向治疗至关重要。由于目前从锶-90制备钇-90所使用的方法不适用于中心/医院放射性药房，因此开发了一种基于电化学分离技术的简易锶-90 - 钇-90发生器系统。
开发了一种两循环电解程序，用于在硝酸盐溶液中从锶-90分离钇-90。第一次电解在pH值为2 - 3的锶-90（硝酸锶）进料溶液中进行90分钟，使用铂电极，电位为 - 2.5 V，电流为100 - 200 mA。第二次电解在3 mM硝酸中进行45分钟，电位为 - 2.5 V，电流为100 mA。在这一步骤中，将第一次电解含有钇-90的阴极用作阳极，同时使用一个新的圆形铂电极作为阴极。第二次电解后沉积在圆形阴极上的钇-90溶解在醋酸盐缓冲液中，以获得适用于放射性标记的醋酸钇-90。
每个循环中钇-90的回收率>96%，经衰变校正后的总产率>90%。回收的钇-90具有高放射性核素纯度，每37 GBq（1 Ci）钇-90中锶-90的含量仅为30.2±15.2 kBq（817±411 nCi）（0.817±0.411 ppm）。使用高达1.85 GBq（50 mCi）的锶-90可以证明能够进行一致且重复的分离。该发生器被命名为“Kamadhenu”，即印度神话中能永远产奶的母牛。
已开发出一种适用于中心放射性药房的技术，可用于获得治疗量的纯钇-90。
