Chloroquine diphosphate, a highly water-soluble drug, was encapsulated by using a non-solvent addition coarcevation method. The coating material employed was Eudragit RS100. The liquid manufacturing vehicle was tetrahydrofuran (THF) while the non-solvent liquid was cyclohexane. Polyisobutylene (PIE) was used as an anti-aggregating agent. Particle size as well as shape evaluation was performed. Total drug content, in vitro drug release (from the microcapsules) as well as tasting test experiments were performed. The release studies on the microcapsules revealed an in vitro prolonged release effect while at the same time the bitter taste of the drug appeared to have been considerably masked by this method.