EFFECT OF AQUEOUS POLYMER DISPERSIONS ON PROPERTIES OF DICLOFENAC ALGINATE BEADS AND IN-VIVO EVALUATION IN RATS/

Alginates, which are natural biopolymers, were used to prepare control led-release beads of diclofenac sodium in an entirely aqueous medium. Their morphology was evaluated by scanning electron microscopy. Calciu m alginate beads with and without Aquacoat and Eudragit NE30D were tes ted for drug release rate in vitro and in vivo in Wistar rats for the inhibition of carrageenin-induced paw edema. Beads containing Eudragit NE30D provided a zero-order diclofenac sodium release rate. The beads released diclofenac sodium by diffusion and matrix erosion. Drug rele ase was faster in pH 7.4 buffer than in distilled water: By the gradua l pH change method, drug release was negligible in an acidic medium an d gradually increased by the increasing pH. No statistically significa nt differences were observed between Eudragit and Aquacoat containing systems in the rat model for reducing carrageenin-induced paw edema. I t was shown that the alginate-based beads with the added dispersions o f water-insoluble polymers can sustain low molecular weight drugs more successfully. Working in an environment free of organic solvent is al so art additional advantage.