Self-emulsifying Drug Delivery Systems as a Paradigm for Enhancing Bioavailability of Phytoconstituents

Abstract

The major limitations associated with phytoconstituents are their poor solubility and bioavailability in gastric fluid, which limit their further exploration to their full potential. To overcome these challenges, self-emulsifying formulations have emerged as a promising strategy to enhance the solubility and bioavailability of herbal molecules and phytoconstituents with poor aqueous solubility. SEDDS formulations typically comprise an isotropic mixture of oil, surfactant, and co-surfactants. The concentration of these excipients is chosen based on pre-formulation studies, such as phase equilibrium studies, the oil’s solvent capacity for the drug, and the mutual miscibility of the excipients. This review primarily discusses the development of SEDDS and the role of different excipients in tailoring the oral bioavailability and aqueous solubility of lipophilic phytoconstituents. The various ratios of primary excipients used by different researchers, along with their effects on drug solubility and bioavailability, are presented in a tabular format. Relevant research databases, including PubMed, Google Scholar, Google Patents, Scopus, and Web of Science, were used to review the research data for various self-emulsifying herbal formulations using the keywords “Self-emulsifying, SEDDS, SMEDDS, SNEDDS, Lipid formulation, LFCS”. The manuscript further explores the potential applications of SMEDDS and SNEDDS in the treatment of various ailments using different herbal extracts and phytoconstituents. In conclusion, the review effectively presents the role of SEDDS in improving the oral bioavailability of lipophilic compounds.