Starch-colloidal silicon dioxide mixtures (Era-Tab SP® ) was prepared by co-spray drying and dry mixing methods and the flow ability and tablet properties of both methods were compared in particular with spray dried rice starch (SNR) alone. In co-spray drying, various percentages of rice starch and colloidal silicon dioxide blends were suspended in distilled water and subjected to spray dryer. The dry mixing method was obtained by blending of the colloidal silicon dioxide and spray dried rice starch at various percentages. It was found that co-spray drying of starch-colloidal silicon dioxide mixtures improved flow ability by reducing of the frictional forces between the granules greater than the dry mixing method. SEM micrographs presented the depositions of colloidal silicon dioxide on the surface of agglomerated starch granules obtained from both methods. The addition of colloidal silicon dioxide increased the tensile strength of the compressed tablet especially via the co-spray drying method by increasing the interaction of hydrogen bonding inside the tablet. Moreover, the co-spray drying method also reduced the friability and the disintegration time of the tablets better than the dry mixing method.