LIPID BASED SELF-MICROEMULSIFYING DRUG DELIVERY SYSTEM (SMEDDS) FOR LIPOPHILIC DRUGS: AN ACQUAINTED REVIEW

Abstract

The solubility issue presents serious challenges to the successful development and commercialization of new drugs in the Pharmaceutical industry. By many estimates, approximately 40% of newly discovered drug candidates have little or no water solubility and therefore have low and erratic bioavailability profile. This may lead to high inter and intra subject variability, lack of dose proportionality and therapeutic failure. Various strategies are reported in the literature including micronization, solid dispersions, cyclodextrin complex formation and self-dispersing delivery systems for enhancement of bioavailability of lipophilic therapeutic agents. Among the various approaches, Self micro emulsifying drug delivery system has gained more attention due to enhanced oral bioavailability enabling reduction in dose, more consistent temporal profiles of drug absorption, selective targeting of drugs towards specific absorption window in Gastro intestinal tract and protection from the hostile environment in gut. Self micro emulsifying drug delivery system is an isotropic (one phase system) mixture of oil or modified oils, surfactants, co-surfactants which form fine oil-in-water microemulsion when introduced into aqueous phase under conditions of gentle agitation. The digestive motility of the stomach and intestine provide the agitation necessary for self emulsification in vivo. This review describes about the formulation methodology, evaluation parameters and the future aspects of Self micro emulsifying drug delivery system.