Ngineering of HBsAg Antigen Containing Poly (e- Caprolactone) Microspheres to Tailor Particle Size

The aim of this work was to optimize particle size of Hepatitis B Surface (HBsAg) antigen containing poly(ε-caprolactone) (PCL) microspheres using the water-in-oil-in water solvent evaporation technique. Effects of manufacturing and formulation variables on particle size were investigated. It was observed that microsphere size could be controlled by modification of PCL concentration in the organic phase, polyvinyl alcohol (PVA) concentration in the outer aqueous phase, HBsAg concentration in inner aqueous phase, organic phase volume, and sonication time for primary w/o emulsion preparation. The optimized conditions yielded microspheres with an average particle size of 7.34 μm. Such biodegradable PCL microspheres appear suitable for the use as vaccine adjuvant. Keywords: Microspheres; HBsAg; Poly(ε-caprolactone); Polyvinyl alcohol