Preparation and evaluation of abietic acid microcapsules by a solvent evaporation technique

Abietic acid was isolated from rosin N Grade (ISI) by a simple process and the product was further standardized. Sulphadiazine microcapsules were prepared by the solvent evaporation technique, using abietic acid as a wall-forming material. Discrete, spherical and free-flowing microcapsules were obtained by phase separation induced by solvent evaporation using bentonite as a solid emulsifier. The prepared microcapsules were evaluated for drug content, wall thickness, flow properties, size distribution, density and in vitro dissolution studies in gastric fluid. The effect of various process variables such as agitation speed, coat-core ratio, etc., on the micromeritic and release characteristics has been described.