Abstract

Sodium alginate (SA) and tragacanth gum (TG) blend membranes were prepared by solvent casting method for
the controlled release of verapamil an antihypertensive drug. The prepared membranes were crosslinked with
glutaraldehyde (GA) and were characterized by Fourier transform infrared spectroscopy (FTIR), differential
scanning calorimetry (DSC), X-ray diffraction (X-RD), and scanning electron microscopy (SEM). FTIR was used
to understand the formation of hydrogen bonding due to interaction between SA, TG polymer blend and GA.
The DSC and X-RD studies were performed to understand the crystalline nature of drug after encapsulation into
hydrogel membranes. SEM was used to study the surface morphology of the membranes. In vitro release studies
indicated a dependence of release rate on the extent of crosslinking, amount of drug loading and the amount
of blend composition. The results revealed the slow release rates which were extended up to 12 h. Cumulative
release data were fitted onto to an empirical equation to compute diffusional exponent (n) which indicates the
non-fickian diffusion.