This is a direct result of the porous
nature of the NaHCO3 containing beads. The
highly dense internal structure of the alginate
beads prepared without gas forming agents was
expected to retain the drug more effectively. Conversely,
increasing the CaCO3 weight ratio prolongs
the release rate of riboflavin from the
alginate matrix. The effect is observed in spite of
increased bead porosity and pore size and may be
due to the internal ionotropic gelation effect of
CaCO3