The modern drug delivery system of hydrophobic drugs presents a main challenge because of the poor aqueous solubility of such compounds. Self emulsifying drug delivery systems (SEDDS) are usually used to enhance the bioavailability of hydrophobic drugs. SEDDS can be administered orally in soft or hard gelatin capsules and form fine relatively stable oil in water (o/w) emulsions upon aqueous dilution due to the gentle agitation of the gastrointestinal fluids. From time to time so many workers have claimed different rational applications of Self-emulsifying formulation for increcing bioavailability and site-specific targeting of highly lipophilic drugs. Significant improvement in the oral bioavailability of these drug compounds has been demonstrated for each case. The fact that almost 40% of the new drug compounds are hydrophobic in nature implies that studies with SEDDS will continue, and more drug compounds formulated as SEDDS will reach the pharmaceutical market in the future. The present article gives an overview of the Composition, mechanism, advantages, disadvantages, characterization, recent advancements, patents related information of SEEDS and commercial products approved for oral transmucosal administration.