Self-Micro Emulsifying Drug Delivery Systems (SMEDDS) for Phytopharmaceuticals

Phyto-pharmaceuticals have gained increasing attention due to their therapeutic potential and natural origin. However, their clinical utility is often compromised by poor aqueous solubility, low permeability, chemical instability in the gastrointestinal tract, and extensive first-
pass metabolism, leading to poor oral bioavailability. Self-Micro- emulsifying Drug Delivery Systems (SMEDDS) have emerged as a promising lipid-based delivery approach to overcome these challenges. SMEDDS are isotropic mixtures of oils, surfactants, and co-surfactants that spontaneously form fine oil-in-water micro- emulsions upon mild agitation in gastrointestinal fluids. These systems significantly enhance drug solubilization, protect labile constituents, and improve intestinal absorption and lymphatic
transport. This chapter provides a comprehensive overview of the formulation, characterization, and evaluation of SMEDDS, with special emphasis on their application in enhancing the bioavailability of key herbal drugs such as curcumin, silymarin, boswellic acids, and quercetin. Moreover, the chapter explores existing hurdles, regulatory considerations, and the evolving clinical potential of SMEDDS in the advancement of phyto-pharmaceutical drug delivery.