A REVIEW ON SELF-MICRO EMULSIFYING DRUG DELIVERY SYSTEM

Oral route has always been preferred route for formulators and has dominated over other routes of administrations. However this preferred route is limited to those drugs molecule that are permeable across the gastric mucosa and are at least sparingly soluble. 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. Also nowadays much attention has been paid to the lipid based formulations. Some examples of marketed lipid based formulations are Sandimmune Neoral (Cyclosporine A), and Fortovase (Saquinavir), with much attention focused on self micro-emulsifying drug delivery systems (SMEDDS). SMEDDS 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. This article gives a complete overview of SMEDDS as a promising approach to effectively tackle the problem of poorly soluble molecules.