Studies on the syntheses and properties of phosphorus-containing polyanhydrides for DDS

Phosphorus-containing polyanhydrides(2a, 2b) and copolyanhydrides (la-CPP, Ib-CPP) were synthesized by melt polycondensation using monomers bis(p-carboxyphenyloxyethyl); ethyl phosphate and his (p-carboxyphenyloxyethyl), phenyl phosphate, Their chemical structures were confirmed by H-1 NMR, FTIR, UV and elementary analysis, The average molecular weight and store stability as well as thermostability of these polyanhydries and copolyanhydrides were investigated, The degradation of polyanhydrides in vitro in phosphate buffer solution at 37 degrees C was monitored by HPLC, The experimental data revealed that fission of phosphate bond took place after that of the anhydride bond, Enzymatic degradation showed that ribonuclease and alkaline phosphatase can catalyze and accelerate the degradation of these phosphorus-cotaning polyanhydrides. Drug release profile of ciprofloxacin was also studied.