It is intended to provide sustained theophylline-release particles that are sustained theophylline-release particles comprising a polyglycerol fatty acid ester as a matrix base, having a uniform cored particle structure, being able to effectively masking the unpleasant taste of the drug and having excellent properties of controlling the release (elution) of the drug and a high storage stability. More specifically speaking, a process for producing sustained theophylline-release particles characterized by comprising heating a matrix base containing a polyglycerol fatty acid ester, theophylline and ethyl cellulose to give a liquid mixture, spray-cooling the liquid mixture to give spherical cored particles having an average particle size of 250 mum or less and then melt-coating the cored particles with a fine powder, etc.
