[A water-soluble synthetic polymer, alpha,beta-poly(hydroxyalkyl)-DL-asparamide, and conjugating drug]

A water-soluble polymer alpha,beta-poly (hydroxyalkyl)-DL-asparamide was synthesized by polysuccinimide(PSI) and different lengths of hydroxyalkyls, including alpha,beta-poly(hydroxyethyl)-DL-asparamide(PHEA), alpha,beta-poly(hydroxypropyl)-DL-asparamide(PHPA), and alpha,beta-poly(hydroxybutyl)-DL-asparamide(PHBA). These polymers were characterized by differential scanning calorimetry(DSC) and infrared spectrophotometry(IR). Stability and acutetoxicity of these polymers were studied. The experiment indicated that these materials were of low-toxicity and high stability. Acetylsalicylic acid, as a model drug, was conjugated into polymers; the drug loadings were 38.63%, 37.68% and 38.70% respectively. Polymer drugs were made into cylinder, and in-vivo release in rabbits was set out. It showed that the longer the spacer was linked into the polymer, the faster the drug was released.