In modern drug discovery techniques, there has been a consistent increase in the number of poor water soluble drug candidate compounds, and currently more than 50% of new pharmacologically active chemical entities are lipophilic and exhibit poor water solubility. Self-emulsifying drug delivery (SEDDS) is the one of the method for the improvement of oral bioavailability. SEDDS are the isotropic mixtures of oils, surfactants, solvents and co-solvents. Self-emulsifying drug delivery systems (SEDDS) possess unparalleled potential in improving oral bioavailability of poorly water-soluble drugs.
Following their oral administration, these systems rapidly disperse in gastrointestinal fluids, yielding micro- or nanoemulsions containing the solubilized drug. Owing to its miniscule globule size, the micro/nanoemulsifed drug can easily be absorbed through lymphatic pathways, bypassing the hepatic first-pass effect. We present an exhaustive and updated account of numerous literature reports and patents on diverse types of self-emulsifying drug formulations, with emphasis on their formulation, characterization, and systematic optimization strategies. This review article tries to describe the formulation of SEDDS and also talks about the construction of the phase diagram for SEDDS. It describes the mechanism involved in self-emulsification and the bio-pharmaceutical aspects involved. The advantages of SMEDDS over conventional emulsions are listed. Some of the marketed preparations of SEDDS are listed.
Key words: Nanoemulsified drugs, Self-emulsifying drug delivery, SEDDS, SMEDDS