MULTIPARTICULATE DELIVERY OF DICLOFENAC SODIUM BY COMPLEX COACERVATION USING A BINARY MIXTURE OF IRVINGIA/GELATIN GUMS
This study was aimed at preparing and evaluating sustained release multiparticulate drug delivery systems containing diclofenac sodium encapsulated through the complex coacervation of irvingia and gelatin gums in comparison with coacervates formed from acacia/ gelatin gum complex. Irvingia gum was extracted from Irvingia gabonensis seeds by cold maceration in acetone after defatting with chloroform/methanol mixture in a 2:1 ratio. The viscosities of 1 and 3 %w/v aqueous dispersions of the gelatin, acacia and irvingia gums were determined. The coacervates were made by dispersing a solution of diclofenac sodium in ethanol in the gelatin mucilage and then incorporating the gum mucilage with continuous stirring using a magnetic stirrer. This was done at different ratios strengths, pH and temperatures. The coacervates were evaluated for angle of repose, Hausner ratio, Carr`s compressibility index and degree of drug entrapment before filling them into hard gelatin capsule for drug release studies. The same was done for acacia/ gelatin coacervates and the physical mixtures of the two compositions. The irvingia gum dispersions had higher viscosities than acacia and gelatin gum dispersions. The optimally generated coacervates had fair to good flow. The coacervates prepared from 1:2 ratio of irvingia/ gelatin gum complex at 25 oC and pH of 4.6 gave the best yield, fair to good flow properties and sustained drug release profile as compared with the coacervates prepared from acacia/ gelatin complex. Therefore, irvingia/ gelatin gum complex coacervate could be a better substitute for the sustained delivery of diclofenac sodium