As a consequence of modern drug discovery techniques, there has been a
steady increase in the number of new pharmacologically active lipophilic
compounds that are poorly water-soluble. Approximately 40% of new drug
candidates have poor water solubility and oral delivery of such drugs is
frequently associated with implications of low bioavailability, high
intra and inter subject variability and therapeutic failure. It is a
great challenge to convert these molecules into orally administered
formulations with sufficient bioavailability. Among the approaches to
improve the oral bioavailability of these molecules, the use of
self-emulsified drug delivery systems (SEDDS) has been shown to be
reasonably successful.SEDDS is ideally an isotropic mixture of oils and
surfactants and sometimes co-solvents. Hydrophobic drugs can be
dissolved in these systems, enabling them to be administered as a unit
dosage form for per-oral administration. When such a system is released
in the lumen of the gastrointestinal tract, under conditions of gentle
agitation provided by digestive motility of stomach and intestine, it
spontaneously disperses to form a fine relatively stable o/w emulsion
(micro/nano).