Characterization of Protein Loaded Poly(E-Caprolactone) Microparticles Based on a Factorial Design

This study was designed to systemically investigate the characteristics of bovine serum albumin (BSA) loaded poly(e- caprolactone) (PCL) microparticles based on a 24 factorial experiment. The influences of polyvinyl pyrrolidone (PVP) concentration, BSA/PCL ratio, w/o/o/o ratio, and PEG/PCL ratio on the surface morphology, particle size as well as the yield of microparticles, encapsulation efficiency of BSA , and in vitro release property were evaluated. The microparticles were prepared by w/o/o /o solvent evaporation method. The structure of BSA remained its integrity via this technique. The mean particle sizes of BSA-loaded microparticles were in the range of 20 ~ 50 mm, and highly porous morphology existed in these microparticles irrespective of the formulations. The production yields of microparticles were in the range of 52.1 ~ 89.0%, and the encapsulation efficiencies were in the range of 13.8 ~ 68.3% . The burst release of BSA was in the range of 6.9% ~ 69.0%. The volume ratio of multi -phases significantly affected the encapsulation efficiency of BSA in PCL microparticles, and the initial amount of BSA encapsulated by PCL in terms of BSA/PCL ratio significantly affected the amount of BSA released at the end of 14 days (p < 0.05)