Albumin-loaded PLA and PLGA microspheres: in vitro evaluation

Polylactide (PLA) and poly(lactide-co-glycolide) (PLGA) microspheres containing bovine serum albumin (BSA) as a model protein were prepared by an solvent extraction procedure using water-in oil-in water complex emulsion system. The effects of process parameters on morphology, particle size, protein loading and in vitro release properties of microspheres were studied. The encapsulation efficiency was very high ranging from 75% to 99%. The in vitro release profile was described as bi-phasic process with an initial burst effect and the second sustained release phase and it was dependent on the type of polymer used, and BSA loading of microspheres.