decanedioic acid-4,4'-(1,3-propanediylbis(oxy))bis(benzoic acid) copolymer [ DCA-PDB,Gliadel,PCPP-SA,p(CPP-SA),poly(bis(4-carboxyphenoxy)propane) anhydride sebacic acid polymer ] biodegradable polymeric matrix that can be surgically implanted for the interstitial delivery of drugs, such as BCNU, in the brain