As a result, it seemed that these dispersions were physically stable under the storage conditions. However, with regard to the observations from rheological, morphological, and DSC analyses, one cannot connect those results with the obtained particle size and zeta potential data in order to predict the physical stability of the loaded-SLNs (Lippacher et al., 2004). It is worth to note that the determination of hydrodynamic diameter and zeta potential of the SLN dispersions were performed in the dilute state where the interparticle interaction between particles is negligible; therefore, it cannot represent the real condition of the prepared semi-solid dispersions.