Self-micro emulsifying drug delivery systems: State-of-art a technology to enhance the solubility of poorly water-soluble drug

Abstract

As new technologies are invented, research in the discovery of new active pharmaceutical moieties is reverberating now a day. Drug solubility is an extensive challenge for formulation scientists as approximately 35-40% of newly discovered drugs show lipophilicity. Low solubility is a rate limiting step for drug dissolution and extends of drug absorption to the systemic circulation. Poor dissolution results in low bioavailability, leading to difficulty to achieve desired therapeutic effect. Drug solubility can be increased by different methods like micronization, solid dispersion, salt formation, complexation etc. Self-micro emulsifying Drug Delivery System (SMEDDS) is in fame for enhancing solubility of poorly aqueous soluble drugs. Self-emulsifying drug delivery system, Self-micro emulsifying drug delivery system (SMEDDS) are isotropic mixers of oil, surfactant, drug and co-solvent which spontaneously form transparent micro-emulsions. When SMEDDS formulation administered orally, the solution disperses in GI fluid and instantly forms a fine emulsion by which drug gets a larger surface area which leads to quick dissolution of the drug. Objective of the present review is to update about advancements associated with SMEDDS preparation. It elaborates the evaluation tests required to analyse selfmicro emulsifying drug delivery systems. This review article also highlights on recent patents on SEDDS, SMEDDS and SNEDDS formulations.