Calcium pectinate gel beads for controlled release drug delivery:: I. Preparation and in vitro release studies

Calcium pectinate gel (CPG) beads of indomethacin, a poorly soluble drug, were prepared by dispersing indomethacin in a solution of pectin and then dropping the dispersion into calcium chloride solution. The droplets instantaneously formed gelled spheres by ionotropic gelation. The effect of several factors such as pectin type, the presence of a hardening agent and the drug loading were investigated on the percentage of drug entrapped, size distribution and drug release from the CPG beads. The release characteristics were studied using the rotating basket dissolution method. Strong spherical beads with narrow size distributions, high yields and good entrapment efficiencies could be prepared. All factors investigated have significantly affected the release of indomethacin from CPG beads. The mechanism of drug release from CPG beads followed the diffusion controlled model for an inert porous matrix. Therefore, calcium pectinate gel could be a useful carrier for controlled release drug delivery of poorly soluble drugs.