Source:
RHEOLOGICA ACTA, Volume 45, Number 5, p.611-620 (2006)
Abstract:
Previous work carried out in our laboratories has focused on the
formation and investigation of a dextran and concanavalin A (con A)
based gel, which has the ability to alter its conformational structure
in the presence and absence of free and terminal glucoses such that a
gel-sol phase transition occurs. Here we report the diffusion and
rheological investigations in to the effects of the addition of insulin
and varyingconcentrations of magnesium chloride hexahydrate
(Mg(2)Cl(2)6H(2)O) at 20 and 37 degrees C. Rheological examination of
glucose-sensitive (dextran-con A) gels were conducted using a cone and
plate viscometer used in continual rotation and oscillatory modes. The
results are interpreted in terms of the structure of the gel network
and suggest rheological assessment provides an effective method of
assessing the properties of gel systems. The subsequent testing of such
formulations in in-vitro diffusion experiments revealed a reduction in
the rate of diffusivity in the insulin marker, poly R-478 dye. The
performance of this self-regulating drug delivery system has been
examined and the addition of insulin and magnesium chloride may alter
the way in which the gel operates as a drug delivery device and in the
delivery of insulin. This may have implications for other ligands.
