Isotope preparation method

Abstract

The present invention provides a method for the generation of 223 Ra of pharmaceutically tolerable purity comprising i) preparing a generator mixture comprising 227 Ac, 227 Th and 223 Ra; ii) loading said generator mixture onto a strong base anion exchange resin; iii) eluting said 223 Ra from said strong base anion exchange resin using a first mineral acid in an alcoholic aqueous solution to give a first eluted 223 Ra solution; iv) loading the 223 Ra of the first eluted 223 Ra solution onto a strong acid cation exchange resin; and v) eluting the 223 Ra from said strong acid cation exchange resin losing a second mineral acid in aqueous solution to provide a second eluted solution. The invention additionally provides products of corresponding purity and/or products obtained or obtainable by such a method.

1 - 24 . (canceled) 
     
     
         25 )  223 Ra comprising no more than 0.05 Bq  227 Ac per 1MBq  223 Ra. 
     
     
         26 )  223 Ra as claimed in  claim 25  formed or formable by a method comprising
 i) preparing a generator mixture comprising  227 Ac,  227 Th and  223 Ra; 
 ii) loading said generator mixture onto a strong base anion exchange resin; 
 iii) eluting said  223 Ra from said strong base anion exchange resin using a first mineral acid in an alcoholic aqueous solution to give a first eluted  223 Ra solution; 
 iv) loading the  223 Ra of the first eluted  223 Ra solution onto a strong acid cation exchange resin; and 
 v) eluting the  223 Ra from said strong acid cation exchange resin using a second mineral acid in aqueous solution to provide a second eluted solution. 
 
     
     
         27 )  223 Ra as claimed in  claim 26 , wherein said method additionally comprises the step of:
 x) eluting said  227 AC and  227 Th from said strong base anion exchange resin using a third mineral acid in aqueous solution, whereby to provide a mixture of  227 AC and  227 Th, wherein step x) occurs at any time following step ii).   
     
     
         28 )  223 Ra as claimed in  claim 27 , wherein at least 99.9% of the  227 AC and/or at least 98% of the  227 Th loaded onto the resin in step ii) is recovered in step x). 
     
     
         29 )  223 Ra as claimed in  claim 26 , wherein said method additionally comprises the step of:
 y) storing said mixture of  227 AC and  227 Th for a period sufficient to allow ingrowth of  223 Ra by radioactive decay, whereby to regenerate a generator mixture comprising 227Ac,  227 Th, and  223 Ra.   
     
     
         30 )  223 Ra as claimed in  claim 26 , wherein the method purifies sufficient  223 Ra for more than 10 typical doses. 
     
     
         31 )  223 Ra as claimed in  claim 26 , wherein a  227 Ac radioactivity of at least 500 MBq is employed in step i). 
     
     
         32 )  223 Ra as claimed in  claim 26 , wherein the strong base anion exchange resin is a polystyrene/divinyl benzene (DVB) copolymer based resin and/or is an R—N + Me 3  type (type I) resin or an R—N + Me 2 CH 2 CH 2 OH (Type II) resin. 
     
     
         33 )  223 Ra as claimed in  claim 26 , wherein the first mineral acid is an acid selected from the group consisting of H 2 SO 4  and HNO 3 . 
     
     
         34 )  223 Ra as claimed in  claim 26 , wherein the alcoholic aqueous solution comprises at least one alcohol selected from the group consisting of methanol, ethanol, and isopropanol. 
     
     
         35 )  223 Ra as claimed in  claim 26 , wherein the alcoholic aqueous solution comprises 20 to 99% methanol. 
     
     
         36 )  223 Ra as claimed in  claim 26 , wherein the first eluted solution has a contamination level of no more than 100 Bq  227 Ac per 1MBq  223 Ra. 
     
     
         37 )  223 Ra as claimed in  claim 26 , wherein the steps of loading the generator mixture onto the base anion exchange resin and eluting the first eluted  223 Ra solution provide a separation ratio of  223 Ra to  227 AC of at least 10,000:1. 
     
     
         38 )  223 Ra as claimed in  claim 26 , wherein the strong acid cation exchange resin is a polystyrene/divinyl benzene (DVB) copolymer based resin and/or is of SO 3 H type. 
     
     
         39 )  223 Ra as claimed in  claim 26 , wherein the second mineral acid is an acid selected from the group consisting of H 2 SO 4 , HNO 3 , and HCl. 
     
     
         40 )  223 Ra as claimed in  claim 26 , wherein the aqueous solution does not comprise any significant amount of an alcohol selected from the group consisting of methanol, ethanol, and isopropanol. 
     
     
         41 ) A pharmaceutical composition comprising the  223 Ra, wherein said radium comprises less than 45 Bq  227 AC per 1MBq  223 Ra. 
     
     
         42 )  223 Ra as claimed in  claim 32 , wherein said DVB copolymer based resin contains 1-95% DVB. 
     
     
         43 )  223 Ra as claimed in  claim 33 , wherein the first mineral acid is HNO 3 . 
     
     
         44 )  223 Ra as claimed in  claim 33 , wherein the first mineral acid is used at a concentration of 0.01 to 5 M 
     
     
         45 )  223 Ra as claimed in  claim 34 , wherein said alcohol is methanol. 
     
     
         46 )  223 Ra as claimed in  claim 38 , wherein said DVB copolymer based resin contains 1-95% DVB. 
     
     
         47 )  223 Ra as claimed in  claim 39 , wherein the second mineral acid is HNO 3 . 
     
     
         48 )  223 Ra as claimed in  claim 39 , wherein the second mineral acid is used at a concentration of 0.5 to 5 M. 
     
     
         49 )  223 Ra as claimed in  claim 26 , wherein the aqueous solution is substantially free of methanol. 
     
     
         50 ) The pharmaceutical composition of  claim 41 , wherein said pharmaceutical composition comprises at least one pharmaceutically acceptable diluent.