Preparation of ethyl cellulose microcapsules using the complex emulsion method.

In the present work, an investigation was designed to encapsulate a drug with ethyl cellulose using the complex emulsion method. The technique involved the dispersion of the drug in chloroformic solution of ethyl cellulose, followed by emulsification of the polymer solution in water using sodium lauryl sulfate. After continuous stirring for 5 h at room temperature, the solvent evaporates and a rigid polymer film was formed. The optimum surfactant concentration was determined and the effect of different polymer concentrations and core/coat ratios on the quality of the microcapsules produced was investigated. Drug dissolution was retarded as a result of microencapsulation and was controlled by changing core/coat ratios. The dissolution pattern was indicative of the suitability of this technique for the preparation of prolonged action medication.