SYNTHESIS OF C-14-LABELED COPOLYMERS FOR DRUG-DELIVERY STUDIES

C-14-labeled polyanhydride copolymers [(20:80/1,3-bis(p-carboxyphenoxy )-propane (CPP):sebacic acid (SA)I (7 and 13) were synthesized accordi ng to schemes I and II: C-14-labeled sebacic acid (2,9-C-14(2)) (5) an d C-14-labeled CPP 1,3-bis(p-carboxyphenoxy)-propane (labeled at C-l, C-3 of the propyl group) (11) were transformed to the corresponding mi xed anhydrides (6 and 12) as prepolymers respectively by reaction with acetic anhydride. The labeled mixed anhydride prepolymers (6 and 12) were condensed with unlabeled counter-prepolymers (12' and 6') to give the labeled polyanhydride copolymers (7 and 13). The labeled copolyme rs (7 and 13) were identified and characterized by gel permeation chro matography (GPC).