Self micro emulsifying drug delivery system (SMEDDS): An approach to enhance an oral bioavailability

Abstract

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. The oral bioavailability of poorly water soluble drugs may be enhanced when co administered with meal rich in fat has led to increasing recent interest in the formulation of poorly water soluble drugs in lipids. One of the most new way for such a mentioned problem is the Self microemulsifying drug delivery system (SMEDDS). Self micro emulsifying drug delivery systems are isotropic mixtures of oil, surfactant, co-surfactant and drug with a unique ability to form fine oil in water microemulsion upon mild agitation following dilution with aqueous phase. The hypothesis behind dissolution rate enhancement with SMEDDS is the spontaneous formation of the emulsion in the gastrointestinal tract which presents the drug in solubilized form and the small size of the formed droplet provides a large interfacial surface area for drug absorption. This article gives a complete overview of SMEDDS as a promising approach to effectively tackle the problem of poorly soluble molecules.