Abstract
Self- emulsifying drug delivery systems (SEDDS) is the unique trend in the recent era in the novel drug delivery system. SEDDS are usually used to improve the bioavailability of hydrophobic drugs. Self micro emulsifying drug delivery system (SMEDDS) or self micro emulsifying oil formulation (SEOF) is defined as isotropic mixture of oil and surfactants or alternatively one or more hydrophilic solvents and co-solvents. Composition of SEDDS includes oils, surfactants, co solvent/co surfactant and other components. To get a clear picture of all these different systems and due to large number of possible excipients combinations that may be used to assemble SEDDS systems in particular classification system established called lipid formulation classification system (LFCS). According to ‘Reiss’, self emulsification occurs when change in entropy that favors dispersion greater than the energy required to increase the surface area of the dispersion. Pseudo ternary phase diagram is used to map the optimal composition range for three key excipients according to the resulting droplet size following self-emulsification, stability upon dilution and viscosity. SEDDS system is developed from many needs of the society and industry which forms many more advantages over the other drug delivery. Potential limitations to the application of self-emulsifying formulation include poor chemical stability of the drug substance due to excipients catalyzed degradation and precipitation of drug substance in excipients matrix. A greater understanding of chemical and physical mechanism surrounding this incompatibility is needed to resolve this issue and unlock the full potential of self emulsifying formulation.