The aim of this study was to evaluate the influence of the qualitative composition of excipients on formulation technology of hard gelatin capsules containing high amount of dry extract from Aesculus hippocastanum L. (ESAH). The rheological and technological characteristics of ESAH were determined and the influence of pharmaceutical excipients on the properties of mixtures was studied by a 22 factorial design. The dissolution profiles of the capsules containing the best mixtures were obtained using sodium lauryl sulfate aqueous solution 1% (w/v) as medium. The ESAH showed high cohesivity and therefore low flow. Moreover, the ESAH showed lower level of residual moisture and was stable under controlled atmosphere. When considering pre-formulation, the filler/binder materials (microcrystalline cellulose or lactose) and glidant (colloidal silicon dioxide) increased the technological properties of the mixtures in comparison to pure ESAH. In conclusion, the dissolution profiles showed that there was no significant difference between the formulations and the ESAH, which demonstrated totally release after 30 minutes.