Objective: In this study, an attempt has been made to modify k-Carrageenan properties by
grafting acrylamide chain and use to develop a pH sensitive hydrogel beads composed of grafted kcarrageenan
and sodium alginate for the controlled delivery of diltiazem hydrochloride.
Material: The hydrogel beads were prepared by the ionotropic gelation method using aluminium chloride
(AlCl₃) as a cross-linking agent. The characterization of diltiazem HCl loaded beads was done by
scanning electron microscopic, Fourier transform infrared spectroscopic, differential scanning calorimetry
and X-ray powder diffraction analysis.
Result: The surface morphology revealed that the prepared beads were spherical, having rough with microscopic
cracks in the surface. The X-ray diffraction study indicates that the drug was dispersed molecularly
in the polymer matrix and amorphous in nature in the bead. The beads were evaluated for bead
size, drug entrapment efficiency, swelling ratio and in-vitro drug release study. The size of beads was in
decreasing trend with increasing the AlCl3 concentration. The drug entrapment efficiency of the beads
was decreased with the increase in AlCl3 concentration. The swelling of the beads decreased in both
acidic and basic medium with increasing AlCl3 concentration. The drug release rate of beads was decreased
when AlCl3 concentration increased.
Conclusion: The preliminary investigation of the beads developed in this study showed a promising
sustained release profile of the drug. Therefore, the cross-linked hydrogel beads are promising carriers
for oral controlled release of water soluble drug diltiazem HCl.