Self-Emulsifying Drug Delivery System – a New Approach to Enhance Oral Delivery

Self-emulsifying drug delivery systems (SEDDS) have emerged as a promising solution to overcome the limitations of oral drug delivery for hydrophobic drugs. These systems create fine oil droplets or micelle dispersions in gastrointestinal fluids, enhancing drug absorption and bioavailability. SEDDS are composed of natural or synthetic oils, surfactants, and co-solvents, which form a stable emulsion when diluted in water. The mechanism of self-emulsification is not fully understood, but it is influenced by the entropy of the system and the formation of a liquid crystal phase at the droplet surface. SEDDS offer several advantages, including improved solubility, enhanced absorption, ease of manufacture, and consistent results. However, they also have limitations, such as the need for high surfactant concentrations, potential gastrointestinal irritation, and chemical instability of drugs. The development of SEDDS involves a systematic approach, including the preparation of the lipid phase, mixing with surfactants, and optimization using phase diagrams. Characterization of SEDDS involves visual observation, droplet size analysis, zeta potential measurement, emulsification time, cloud point determination, viscosity measurements, liquefaction time, and nuclear magnetic resonance studies. SEDDS have a wide range of applications in the pharmaceutical field, including improved bioavailability, oral drug delivery, reduction of gastric irritation, targeted drug delivery, and versatility in dosage forms. This review provides an overview of the principles, components, advantages, limitations, and applications of SEDDS, highlighting their potential to overcome challenges associated with poorly soluble drugs.