Self-microemulsifying drug-delivery system: Ongoing challenges and future ahead

Abstract

Self-microemulsifying drug-delivery system (SMEDDS) can be defined as an isotropic system containing lipid and surfactant as well as cosurfactant that develop an emulsion in the aqueous fluid after slight agitation. Nearly half of the newly synthesized chemical molecules show less solubility in the aqueous phase, which is the major concern to the efficient delivery of drug molecules and hence decrease the bioavailability of these entities. In addition, SMEDDSs are considered as a prominent platform in resolving poor bioavailability of hydrophobic drugs through oral delivery. However, traditional self-emulsifying systems that are being developed using a liquid phase may exhibit few disadvantages such as in vivo precipitation of bioactive molecules, product handling problems, and restricted lymphatic transport. Moreover, these limitations restrict their prominent applications. In this context the addition of distinct polymeric precipitation inhibitors may facilitate the keeping of the drug in supersaturation state. Furthermore, solid-SMEDDS assist in combating both handling of liquid as well as stability-related issues. In addition the incorporation of medium-chain triglycerides along with antioxidants may also reduce oxidation-related issues of some unsaturated fatty acids. This chapter details in-depth report on distinct kinds of SMEDDS-based formulations via various route, dosage forms, composition, characterization, and their applications. © 2020 Elsevier Inc. All rights reserved..