Self-Emulsifying Delivery Systems for Poorly Absorbed Drugs

Self-emulsifying drug delivery systems (SEDDS) are a type of emulsion that have received particular attention in recent years as a means of enhancing oral bioavailability of poorly absorbed drugs. These systems are ideally isotropic mixture of oil and surfactant (sometimes co-surfactant are added) that form emulsions on mixing with water with little or no energy input. Hydrophobic drugs are dissolved in SEDDS. After administering the drug by this system, emulsion is formed in the GIT by selfemulsification. Generally by this process bioavailability of the drug is increased and quantity required to exert desired effect is decreased. Oil surfactant ratio, amount of surfactant, type of surfactant, nature of oil affect the process of emulsification. In the emulsification process water penetrates into the oil water interface, leading to the formation of liquid crystalline phase, resulting in swelling at the interface. Generally, SEDDS are formed with triglyceride oils and nonionic surfactant. In the GIT, during the digestion of fat, drugs are getting released and lead to increase the absorption of drug by dissolution or by particle charges which increase the bioavailability. Some latest related to SEDDS is described in this review.