Self-Micro Emulsifying Drug Delivery System:An Approach for Enhancement of Bioavailability of Poorly Water Soluble Drugs

The improvement of oral bioavailability of poorly water soluble drug can be considered as one of the greatest challenges in drug formulation. In recent years today, up to 90% of all new chemical entities entering drug development programs possess insufficient aqueous solubility which leads to poor bioavailability, high intra and inter subject variability, lack of dose, gastric and enzymatic degradation of drug. To overcome these problems, various formulation strategies have been developed e.g. (use of surfactants, lipids, permeation enhancers, micronization, salt formulation, cyclodextrins, nanoparticles and solid dispersion) and different technologies of drug delivery system, but SMEDDS is gaining more attention for improving the solubility of lipophilic drug. The present review examine the advances in solid (S-SMEDDS) with regards to the selection of lipid system for current formulation and advantages of SMEDDS over emulsion, difference and similarities between SEDDS and SMEDDS, SMEDDS formulation, excipients and their characteristic, solidification techniques , dosage form of SMEDDS, evaluation of SMEDDS, example of some marketed product.