A polyblend of poly(ortho esters)-poly(ethylene glycol) (POE-PEG) was prepared. The release behavior of the acetanilide-loaded film of the POE-PEG poly blend was studied. Blending POE with water-soluble PEG can promote the release of drug in pH 7.4 PBS buffer at 37 degrees C, while POE has plasticizing effect on PEG. Infrared and X-ray diffraction studies reveal that there is some interaction between POE and acetanilide. The SEM micrographs disclose that the porosity of the drug-loaded film enhances with an increase immersing time.