| abstract |
A polymer with a hydrolytically la-bile backbone and having structure (VIII) wherein R9 is an alkyl, aryl or alkylaryl group with up to 18 carbon atoms having a pendent carboxylic acid group or the benzyl ester thereof; R12 is an alkyl, aryl or alkylaryl group with up to 18 carbon atoms having a pendent carboxylic acid ester group selected from straight and branched alkyl and alkylaryl esters con-taining up to 18 carbon atoms and ester derivatives of biologically and pharma-ceutically active compounds covalently bonded thereto, provided that the ester group is not a benzyl group or a group that is removed by hydrogenolysis; each R7 is independently an alkylene group containing up to four carbon atoms; A is selected from: (a) and (b) wherein R8 is selected from saturated and unsaturated, substituted and unsubstituted alkyl, aryl and alkylaryl groups containing up to 18 carbon atoms; k is between about 5 and about 3,000; and x and f independently range from zero to less than one. |