Preparation and characterization of protein-loaded poly(ε-caprolactone) microparticles for oral vaccine delivery

This paper describes the conditions of preparation of poly(epsilon-caprolactone) (PCL) microparticles with a mean size between 5 and 10 mu m, obtained by a double emulsion-solvent evaporation technique, suitable for oral vaccine delivery. Bovine serum albumin (BSA) was used as water-soluble model antigen for encapsulation. Different parameters influencing the microparticle size, the BSA loading and entrapment efficiency were investigated. Spherical, smooth and homogeneously distributed microparticles were produced with a BSA loading and entrapment efficiency reaching, respectively, 5% (w/w) and 30%. Polyacrylamide gel electrophoresis (PAGE) and isoelectric focusing (IEF) analyses of BSA released from these particles confirmed that the entrapped protein seemed to remain unaltered by the protein encapsulation process. (C) 1999 Elsevier Science B.V. All rights reserved.