Synthesis and characterisation of poly(D,L-lactic acid) idoxuridine conjugate

A new polymeric prodrug was prepared coupling 5-iodo-2'-deoxyuridine (IDU) to poly(D,L-lactic acid) (PLA) via a succinic acid spacer. The PLA-IDU conjugate was characterised by thermal analysis, IR and H-1 and C-13 NMR spectroscopy. The IDU content (0.024 mequiv. g(-1) of PLA) was consistent with the carboxylic acid endgroup present in the polymer sample (0.025 mequiv. g(-1) of polymer). The PLA-IDU conjugate was susceptible to degradation in biological environments containing esterase, whereas IDU was not detected by chemical hydrolysis in pH 7.4 phosphate buffer. The conjugate should be used to prepare injectable microspheres and nanospheres containing IDU chemically coupled to the polymer carrier. (C) 1999 Elsevier Science B.V. All rights reserved.