Poly(D,L-lactide-ran-epsilon-caprolactone)-poly(ethylene glycol)-poly(D,L-lactide-ran-epsilon-caprolactone) as parenteral drug-delivery systems.

P(DLAX-ran-CLY)n-b-PEG-b-P(DLAX-ran-CLY)ns (P(DLAX-ran-CLY)m: Poly(d,l-lactide-ran-epsilon-caprolactone), PEG: Poly(ethylene glycol), X: d,l-lactyl unit ratio, Y: epsilon-caproyl unit ratio, m : molecular weight of P(DLAX-ran-CLY)), were investigated as the novel parenteral drug-delivery system. The thermal behavior in the DSC characterization and variable viscosity with temperature suggest their potential usuage as a injectable drug-delivery system. The variation of tri-block structure affects the drug release behavior by changing the morphology and also by changing the interaction between the polymer matrix and the hydrophilic drug.