Solid-Self Emulsifying Drug Delivery System:Formulation Techniques and Dosage Forms

The drug substance administered by any route must possess some aqueous solubility for systemic absorption. For this purpose, solubility is one of the most important parameter to achieve desired concentration of drug in systemic circulation for therapeutic response. However, more than 40% of new chemical entities exhibit poor aqueous solubility and present a major challenge to modern drug delivery system, because of their low bioavailability. Self-emulsifying drug delivery systems (SEDDS) are usually used to improve the bioavailability of hydrophobic drugs. Conventional SEDDS, however, are mostly prepared in a liquid form, which can produce some disadvantages. Accordingly, solid SEDDS (S-SEDDS), prepared by solidification of liquid/semisolid self emulsifying (SE) ingredients into powders, have gained popularity. This article gives an overview of the recent advances in the study of S-SEDDS, especially the related solidification techniques and the development of solid SE dosage forms. Finally, the existing problems and the possible future research directions in this field are pointed out.