Self-Emulsifying Oral Lipid Drug Delivery Systems: Advances and Challenges.

The attempts to oral delivery of lipids can be challenging. Self-emulsifying drug delivery system (SEDDS) plays a vital role to tackle this problem. SEDDS is composed of an oil phase, surfactants, co-surfactants, emulsifying agents, and co-solvents. SEDDS can be categorized into self-nano-emulsifying agents (SNEDDS) and self-micro-emulsifying agents (SMEDDS). The characterization of SEDDS includes size, zeta potential analysis, and surface morphology via electron microscopy and phase separation methods. SEDDS can be well characterized through different techniques for size and morphology. Supersaturation is the phenomenon applied in case of SEDDS, in which polymers and copolymers are used for SEDDS preparation. A supersaturated SEDDS formulation kinetically and thermodynamically inhibits the precipitation of drug molecules by retarding nucleation and crystal growth in the aqueous medium. Self-emulsification approach has been successful in the delivery of anti-cancer agents, anti-viral drugs, anti-bacterial, immunosuppressant, and natural products such as antioxidants as well as alkaloids. At present, more than four SEDDS drug products are available in the market. SEDDS have tremendous capabilities which are yet to be explored which would be beneficial in oral lipid delivery.