SELF-MICRO EMULSIFYING DRUG DELIVERY SYSTEM (SMDDS): A NOVEL AP- PROACH FOR ENHANCEMENT OF BIOAVAILABILITY

ABSTRACT The oral delivery of lipophillic drugs presents a major challenge because of the low aqueous solubility of such compounds. Self-micro emulsifying drug delivery systems (SMEDDS) have gained exposure for their ability to increase solubility and bioavailability of poorly soluble drugs. SMEDDS are isotropic mixtures of oils, surfactants, solvents and co-solvents and drugs with a unique ability to form fine oil in water microemulsiom upon mild agitation following dilution with aqueous phase. The efficiency of oral absorption of the drug compound from the SMEDDS depends on many formulations related parameters, such as surfactant concentration, oil/surfactant ratio, polarity of the emulsion, droplet size all of which in essence determine the self-micro emulsifying ability. Approximately 40%of new chemical entities exhibit poor aqueous solubility and present a major challenge to modern drug delivery system, because of their low bioavailability