| abstract |
High molecular weight, water-soluble prodrugs of the formula: <IMAGE> (I) wherein: D is a biologically active moiety; M is X or Q; X is an electron withdrawing group; Q is a moiety containing a free electron pair positioned five or six atoms from Y'; Y and Y' are oxygen or sulfur; R is a polyalkylene oxide; and Z is OH, C1-4 all moieties or <IMAGE> are disclosed. In preferred embodiments, the prodrugs contain a polyethylene glycol having a molecular weight of at least about 20,000. |