Effects of reaction condition and feed composition on thermo_gelling behavior of PLGA_PEG_PLGA

Intelligent thermosensitivc formulations based on PLGA-PEG-PLGA triblock copolymer have great potential in biomedical applications, due to their good biocompatibiJity, biodegradability and injectability. The gelation behavior of the synthesized PLGA-PEG-PLGA triblocks was investigated in this study and the effect of PEG molecular weight and lactide to glycolide molar ratio, as well as the reaction time was investigated. Triblocks with PEGI OOO have shown inappropriate gelation; while t hose with higher molecular weight formed gel at body temperature. The insulin release profiles showed an approximately linear release profile without a non-desirable burst effect. Mo:re than 80% of the insulin was released during 4 weeks.