Polycaprolactone-poly(ethylene-glycol) block copolymer. IV: Biodegradation behaviorin vitro andin vivo

The biodegration behavior of polycaprolactone–poly(ethylene glycol) block copolymer (PCL–b–PEG) was identified by degradation tests in vitro and in vivo. The tests in vitro and in vivo were carried out by immersing samples in pH 5.0, 7.2 and 9.0 buffer solutions with or without lipase at 25.0, 37.0 and 50.0±°C, and implanting samples in the back or small intestine of rats. It was found that the degradation rate of the PCL–b–PEG was increased with increasing PEG content, temperature, acidity or alkalinity, and it was accelerated by the presence of enzyme. The fastest degradation rate was observed in the physiological condition of the sample being implanted in the body of animals. It has been shown that the PCL–b–PEG copolymer is a possible biodegradable polymer. © 1997 John Wiley & Sons, Ltd.