SELF–MICROEMULSIFYING DRUG DELIVERY SYSTEM: SPECIAL EMPHASIS ON VARIOUS SURFACTANTS USED IN SMEDDS

The majority of novel chemical entities getting discovered are having low water solubility and it must be addressed to distribute the drug more effectively. SMEDDS, a lipid-based drug delivery approach, is thought to boost oral absorption of less hydrophilic drugs. Surfactants are the major excipients used in SMEDDS as they are responsible for the emulsification process. The two main criteria while choosing a surfactant should be HLB and safety. A high emulsifying property is what the emulsifier employed in SMEDDS formulation is ought to have. The high hydrophilicity and HLB value of a surfactant guarantees instant oil-in-water droplet production and fast dispersion of formulation in aqueous fluids. The most frequently advised and preferred surfactant type used in SMEDDS are non-ionic surfactants with a rather high HLB value. A high concentration of surfactant is required for a stable self – micro-emulsifying drug delivery systems and they usually contain surfactant concentrations in the range of 30% to 60% w/w. Surfactants that are suitable for use in pharmaceuticals include kolliphor RH40, Cremophor® RH40, Polysorbate 80, different grades of glaciers, labrasol, etc. This article reviews SMEDDS and their medicinal usage in drug delivery with a focus on numerous surfactants used in SMEDDS.