Self-Nanoemulsifying Drug Delivery System: Formulation, Characterization and Solidification Approaches

Self-nanoemulsifying drug delivery systems (SNEDDS) represent a transformative approach to overcoming the challenges of poor aqueous solubility and low oral bioavailability, which affect approximately 40% to 70% of new therapeutic moieties. These lipophilic drugs, often categorized as BCS Class II or IV, typically suffer from incomplete dissolution and precipitation in the gastrointestinal tract. SNEDDS are isotropic mixtures of drugs, oils, surfactants, and co-surfactants that spontaneously form fine oil-in-water nanoemulsions with droplet sizes of 200 nm or less when exposed to aqueous media and gentle agitation. This small particle size provides a massive interfacial area, significantly accelerating drug dissolution and enhancing absorption rates. The formulation process involves optimizing components through pseudo-ternary phase diagrams to identify ideal self-emulsification regions. While traditional SNEDDS are liquid-based, modern research focuses on converting them into solid forms (S-SNEDDS) using techniques like spray-drying, physical adsorption, and hot-melt extrusion. These solid dosage forms improve physical stability, reduce manufacturing costs, and prevent issues such as drug leakage or capsule shell interactions. Beyond oral delivery, SNEDDS show immense potential for ocular, transdermal, and parenteral applications. By protecting drugs from enzymatic degradation and providing consistent plasma profiles, SNEDDS stand as a commercially viable and scientifically robust strategy for enhancing the delivery of challenging lipophilic compounds in modern medicine. Therefore, the preparation, components, self nano emulsification process, biopharmaceutical features, characterization techniques, and applications of self-nanoemulsifying delivery systems (SNEDDS) are described in this study.