New unsaturated polyesters as injectable drug carriers

Abstract

New unsaturated polyesters of poly(fumaric acid–glycol–sebacic acid) copolymers and poly(maleic anhydride–glycol–sebacic acid) copolymers were prepared by melt polycondensation of the corresponding mixed monomers: sebacic anhydride, fumaric acid or maleic anhydride and glycol. Methyl-methacrylate (MMA) was used as crosslinker and dimer acid was used as thinner. In vitro studies showed that those copolymers are degradable in phosphate buffer at 37 °C and poly(fumaric acid–glycol–sebacic acid) has proper drug release rate as drug carriers. The biocompatibility of poly(fumaric acid–glycol–sebacic acid) copolymers under mice skin was also evaluated; macroscopic observation and microscopic analysis demonstrated that the copolymer is biocompatible and well tolerated in vivo. The injected poly(fumaric acid–glycol–sebacic acid) [molar ratio M fumaric acid: M glycol: M sebacic acid = 1.75:2.20:0.25] containing 5% adriamycin hydrochloride (ADM) in the mice bearing Sarcoma-180 tumor exhibited a good antitumor efficacy. The volume doubling time (VDT) (18 ± 2.5 days) of the tumor growth by this treatment was longer than that (7 ± 0.9 days) by the subcutaneous injection of ADM.