Abstract:

The currently available yellow fever vaccines are thermally unstable and involve huge costs during preservation and administration. Microencapsulation with thermally stable coating materials is considered as a means of protecting yellow fever vaccines from thermal degradation. Silica nanoparticles have thermal stabilizing abilities but do not possess film forming properties. It is proposed that polymer-silica blends might be a good coating material for microencapsulation. This study is aimed at investigating the compatibility and efficiency of blends of selected polymers with silicon obtained from rice husk ash (RHA) in microencapsulating yellow fever virus vaccine. The encapsulated yellow fever vaccine was characterised by FTIR and SEM-EDX spectroscopy, and the vaccine encapsulation efficiency was determined. FTIR spectra of the individual components and final encapsulated vaccine showed good chemical compatibility of all the ingredients. SEM studies of the products revealed uneven and rough surfaces with shrinkages. The vaccine encapsulation efficiency was 66.7%. Altogether, these results suggest that polymer-RHA silica blend can be used in microencapsulating yellow fever virus vaccine.