SELF EMULSIFYING DRUG DELIVERY SYSTEM (SEDDS): A TECHNIQUE TO IMPROVE ORAL BIOAVAILABILITY OF HYDROPHOBIC DRUGS

The oral delivery of hydrophobic drugs presents a major challenge because of the low aqueous solubility of such compounds. Self emulsifying drug delivery systems (SEDDS), which are isotropic mixtures of oils, surfactants, solvents and co-solvents/surfactants, can be used for the design of formulations in order to improve the oral absorption of highly lipophilic drug compounds. SEDDS can be orally administered in soft or hard gelatin capsules and form fine relatively stable oil−in−water (o/w) emulsions upon aqueous dilution owing to the gentle agitation of the gastrointestinal fluids. The efficiency of oral absorption of the drug compound from the SEDDS depends on many formulation−related parameters, such as surfactant concentration, oil/surfactant ratio, polarity of the emulsion, droplet size and charge, all of which in essence determine the self-emulsification ability. Thus, only very specific pharmaceutical excipients combinations will lead to efficient self-emulsifying systems. Although many studies have been carried out, there are few drug products on the pharmaceutical market formulated as SEDDS confirming the difficulty of formulating hydrophobic drug compounds into such formulations. This article gives an overview of various advantages and disadvantages, composition, mechanism, characterization, biopharmaceutical aspects, application, developments of SEDDS and recent advancement in SEDDS