In the presence of pancreatin (Fig. 4A), the blg/Lyso microspheres
offered little protection to D3 due to the rapid release of
the vitamin. Indeed, after the first hour of digestion over 75% of
the vitamin was released from the blg/Lyso microspheres. This
result confirms that the formation of the blg/Lyso microspheres
concomitantly leads to a substantial modification of the structure
of blg and/or Lyso (Howell & LiChan, 1996). Accordingly, the target
amino acids become accessible to trypsin and chymotrypsin, which
consequently affects the binding of D3 to the blg/Lyso complex. In
that context, the higher stability of the D3-loaded blg/Lyso microspheres
in the absence of pancreatin during the first four hours
in SIF can be understood