Self-Emulsifying Drug Delivery Systems: An Attempt to Improve Oral Absorption of Poorly Soluble Drugs

Self emulsifying drug delivery systems (SEDDS) have emerged as a promising strategy for the efficient delivery of hydrophobic drugs because of their versatile features and unique advantages. The oral route of drug delivery is typically considered the preferred and most patient convenient means of drug administration. However, more than 40% of new chemical entities exhibit poor aqueous solubility. SEDDS have gained exposure for their ability to increase solubility and bioavailability of poorly soluble drugs. SEDDS are isotropic mixtures of oils and surfactants, sometimes containing cosolvents, and can be used for the design of formulations in order to improve the oral absorption of highly lipophilic compounds. In SEDDS mixture of hydrophobic drug, surfactant with or without cosurfactant is mixed and then formulated either in soft gelatin capsule or in hard gelatin capsule. After administering the drug by this system, emulsion is formed in the GIT with aqueous GI fluied due to peristaltic movement of GIT. SEDDSs typically produce emulsions with a droplet size between 100–300 nm while self-microemulsifying drug delivery systems (SMEDDS) form transparent microemulsions with a droplet size of less than 50 nm. When compared with emulsions, which are sensitive and metastable dispersed forms.