METHOD FOR PURIFICATION OF 225AC FROM IRRADIATED 226RA-TARGETS

摘要

A method for purifying 225>Ac (I) from irradiated 226>Ra (II) targets involves eluting all the (I) and (II) with acid, separating (I) from (II) and other radium isotopes by extraction chromatography using a solid support coated with N,N-dialkylamidomethyl-diorganophosphine oxide in a trialkyl phosphate, and then separating (I) from 210>Po and 210>Pb by extraction chromatography on a solid support coated with optionally substituted bis-cyclohexano-18-crown-6 in a 4-12C alkanol.. A method (M1) for purifying 225>Ac from irradiated 226>Ra targets (made on a support) involves (a) eluting the target with nitric or hydrochloric acid under reflux to remove all the 225>Ac and 226>Ra, (b) removing the HCl (if used) and redissolving the material in nitric acid, (c) concentrating the extract, (d) separating the 225>Ac from 226>Ra and other radium isotopes by extraction chromatography using a solid support coated with an extraction system comprising compound(s) of formula (I) in compound(s) of formula (II), (e) eluting the retained 225>Ac from the stationary phase with dilute nitric or hydrochloric acid ( 226>Ra is eluted in stage (d)), (f) separating the 225>Ac from 210>Po and 210>Pb by extraction chromatography using a solid support coated with an extraction system comprising compound(s) of formula (III) in compound(s) of formula R 10>-OH (IV), (g) using 2M-HCl as mobile phase and (h) recovering 225>Ac from the eluate, the 210>Po and 210>Pb being retained on the solid support. R1, R2 : octyl, n-octyl, phenyl or (1-3C alkyl)-substituted phenyl; R3, R4 : n- or iso-propyl, or n- or iso-butyl; R5-R7 : 2-5C alkyl, preferably n- or iso-butyl; R8, R9 : H, 1-5C alkyl or tert.-butyl; R10 : 4-12C alkyl. Independent claims are included for (1) a method (M2) for purifying 225>Ac as above, in which the solid support in stage (d) is coated with compound(s) of formula (IA) and stage (e) involves elution with 0.3-0.01M nitric acid or 1-0.05M hydrochloric acid (2) a method (M3) as above in which the support in (d) is coated with compound(s) of formula (IB) and stage (e) involves elution with 0.02-0.1M nitric acid (3) pharmaceutically-acceptable radionuclide compositions containing 225>Ac and obtained by the above methods. R1a-R4a : octyl or 2-ethylhexyl. ACTIVITY : Cytostatic. No biological data given. MECHANISM OF ACTION : None given.