Radiolabelling of polymer microspheres for scintigraphic investigations by neutron activation. 1

Eudragit RS: sulphasalazine microspheres containing 0.08 percent w/w samarium oxide (Sm2O3) have been produced using a conventional emulsification-solvent evaporation technique. Direct quantification of incorporated Sm2O3 was achieved using X-ray fluorescence spectroscopy. The efficiency of Sm2O3 incorporation increased with concentration but microsphere yield, appearance , drug content and drug release rate were unaffected by Sm2O3 content over the concentration range investigated. Incorporation of Sm2O3 by solvent evaporation would appear to offer a convenient method for producing microspheres to be radiolabelled by neutron activation for use in scintigraphic studies. (author). 8 refs.; 1 fig.; 2 tabs