Human insulin-DEAE (diethyl amino ethyl) dextran complex and human insulin DEAE-dextran complex in liposomes were encapsulated in cellulose acetate butyrate (CAB) microcapsules by the emulsion non-solvent addition method. The ratio of core-to-coat used was 1:1. The average diameters of the complex microcapsules and the complex liposome microcapsules were 239.5 +/- 77.5 and 182.9 +/- 52.2 mu m respectively. In vitro dissolution studies of both types of microcapsules in simulated intestinal fluid at pH 7.2 showed a sustained release of the complex and the complex liposome microcapsules with t(50) = 1.5 h and 4 h respectively. This study can be applied to the further development of oral formulations of human insulin liposomes for diabetic treatment.