The oral route is one of the most preferred ways for chronic drug therapy; but the drug dissolution is usually a rate determining step of the absorption processes for poorly water soluble drugs. Approximately 40% of marketing products are poorly soluble or lipophilic compound that lead to restricted oral bioavailability. To solve this problem, numerous methods such as solid dispersions, liposomes, use of cyclodextrins, nanoparticles, salt formation are utilized. Lipid based formulation is a useful route for enhancing oral bioavailability of biopharmaceutics classification system, Class-2 drugs. Various types of lipid based formulation exist such as emulsion, self-emulsifying drug delivery systems, self-microemulsifying drug delivery systems, and solutions of the drug in lipid medium. Self-emulsifying drug delivery system is one type of lipid based formulation that is defined as isotropic mixtures of natural or synthetic oils, non-ionic surfactants or one/more hydrophilic solvent and co-solvents/surfactant. Selfemulsifying drug delivery systems are stable systems that increase the drug dissolution, provided by a large interfacial area of dispersion in oral administration. These systems form fine emulsions in the gastrointestinal tract with mild agitation, provided by gastric mobility and provide a large interfacial area for drug partitioning between oil and water phases, which increases in solubility and expand absorption. Potential advantages of these systems include the increased oral bioavailability, reduced in needed dose, controlled drug delivery, selective drug targeting, and advanced intestinal lymphatic transport of drugs that would be useful in reducing first pass of the drugs.