Background: PCL has a long history as an industrialized biomaterial for preparing microspheres,
but its hydrophobic property and slow degradation rate often cause drug degeneration, quite
slow drug release rate and undesirable tri-phasic release profile.
Materials and Methods: In this study, we used the blending material of PLGA-PEG-PLGA and PCL
to prepare microspheres. The microspheres degradation and drug release behaviors were evaluated
through their molecular weight reduction rate, mass loss rate, morphology erosion and drug release
profile. The hydrophilic PLGA-PEG-PLGA is expected to improve the degradation and drug release
behaviors of PCL microspheres.
Results: Microspheres in blending materials exhibited faster erosion rates than pure PCL microspheres,
forming holes much quickly on the particle’s surface for the drug to diffuse out. A higher proportion
of PLGA-PEG-PLGA caused faster degradation and erosion rates. The blending microspheres
showed much faster drug release rates than pure PCL microspheres.
Conclusion: With blending of 25wt% PLGA-PEG-PLGA, the release rate of microspheres speeded up
significantly, while, with a further increase of PLGA-PEG-PLGA proportion (50%, 75%, 100%), it accelerated
a little. The microspheres with PCL/PLGA-PEG-PLGA of 1/1 exhibited a linear-like drug
release profile. The results could be a guideline for preparing microspheres based on blending materials
to obtain a desirable release.