Formulation And Evaluation Of Ethyl Cellulose-Coated Diclofenac Sodium Microcapsules : Influence Of Solvents

The influence of three solvents for the polymer (chloroform, dichloromethane and ethyl acetate) employed in the preparation on the drug release from ethyl cellulose microcapsules was studied. Diclofenac sodium was used as core and microcapsules were prepared by an emulsion solvent evaporation method. All the three solvents gave discrete, large sized, free flowing spherical microcapsules. The microcapsules were evaluated for size analysis, drug content, microencapsulation efficiency, wall thickness, drug release characteristics, influence of solvent employed on diclofenac sodium release from microcapsules, surface characteristics. Diclofenac release from the microcapsules was, followed first order kinetics and influenced by the size of the microcapsules and the solvent employed in their preparation. Among the solvents employed chloroform was found to be more suitable for slow release of diclofenac from ethyl cellulose microcapsules.