New polyanhydrides made from a bile acid dimer and sebacic acid: Synthesis, characterization, and degradation

New degradable polyanhydrides have been prepared by polycondensation from a dimer of one of the natural bile acid, lithocholic acid, and by copolymerizing the bile acid dimer with different amounts of sebacic acid (50, 80, and 90 wt %). The homo- and copolymers have shown near zero-order kinetics in the degradation and release studies, carried out in a phosphate buffer environment (pH 7.4) at; room temperature. The results showed that; the degradation and release rates of the polymers could be adjusted by the copolymer composition. The duration of the samples in the pellet form ranged from several weeks to about 5 years (by extrapolation). No apparent toxicity was observed for the polymer when tested in vivo with cells from normal human and pig tissues. The study showed that these new degradable polymers can be potentially used as controlled release systems.