Controlled release of sodium dicofenac from chitosan/carrageenan beads

Abstract

This work aims to study polyelectrolyte complex (PEC) hydrogel beads based on chitosan (CS) and carrageenan (CR) as a sodium diclofenac (DFNa) controlled release device in the simulated gastrointestinal condition. Various factors potentially influencing the drug release, i.e. CS/CR proportion, DFNa content, and types and amount of crosslinking agent, were also investigated. The optimal formulation was obtained with CS/CR proportion of 2/1 and 5% (w/v) DFNa. The controlled release of the drug from this formulation was superior to the other formulations and was able to maintain the release for approximately 8 hours. Upon crosslinking with glutaric acid and glutaraldehyde, the resulting beads were found to be more efficient in the drug prolonged release than their non-crosslinking counterparts. The bead crosslinked with glutaraldehyde was able to control the release of the drug over 24 hours. The difference in the drug release behavior can be contributed to the differences of ionic interaction between the oppositely charged and concentrations of the drug within the beads which depended on the compositions of formulation and pH of dissolution medium. The release of drug was controlled by the mechanism of the dissolution of DFNa in the dissolution medium and the diffusion of DFNa through the hydrogel bead.