Formulation and evaluation of controlled-release of steroidal saponins-loaded collagen microspheres

The purpose of this study was to develop a collagen (COL) microspheres-based steroidal saponin (SS) formulation which was expected to sustain release of SS with high encapsulation efficiency. The microspheres were prepared by water-in-oil-in water double-emulsion solvent evaporation technique with different formulation variables such as concentration of COL and emulsification time. The optimised SS microspheres were prepared successfully with average diameter of 8.68 +/- 0.34 m, encapsulation efficiency up to 67.63 +/- 1.31%, and integrated spherical shape with no drug crystal and porous on its surface. The in-vitro drug release studies showed marked retardation of SS release and higher percentage of COL gave longer drug release profile. Higuchi model was found to be the best fitted for drug release from COL microspheres of all formulations. This may suggest the potential use of SS microspheres for treatment of bone tissue engineering over long periods.