The SeDeM system is a useful tool for the galenic characterization of excipients with respect to their suitability for direct compression. It provide an index of good compressibility (ICG) of material indicating its aptitude to be compressed by direct compression Different excipients were analysed by experimental studies of SeDeM parameters and graphical expression (SeDeM Diagram) to determine whether they were suitable for direct compression. Mathematical equation and properties of excipients were used to identify the best excipient and the optimum amount to be used in the formulation. The results confirm that the SeDeM method is effective tool for development of tablets by direct compression. The application of SeDeM expert system enables selecting excipients with in order to optimize the formula in the preformulation and formulation studies.