Self-emulsifying formulations to augment therapeutic efficacy of nutraceuticals: From concepts to clinic

Abstract

BackgroundNutraceuticals often referred as medicinally or nutritionally functional foods has drawn extensive attention in recent years because of their wide array of pharmacological activities. It has been well established that the consumption of nutraceuticals is consistently linked with protection from chronic diseases such as diabetes, heart disease, cancer and neurodegenerative diseases. However, these nutraceuticals are associated with therapeutic limitations because of their poor aqueous solubility, low permeability, short half-lives which ultimately leads to low bioavailability to humans. Therefore, to overcome these issues self-emulsifying formulation approach which compose of oils, surfactants and co-solvents have been demonstrated to be an encouraging approach for augmenting the bioavailability and therapeutic efficacy of the nutraceuticals. Scope and approachIn this review, we discuss various key constituents in self-emulsifying formulations and provide recent efforts to generate “solid self-emulsifying formulations” and “supersaturable self-emulsifying formulations” to overcome the problems related with liquid self-emulsifying formulations. We also covered the mechanisms by which self-emulsifying formulations can affect nutraceutical absorption, augment the bioavailability and consequently therapeutic efficacy of nutraceuticals after oral administration. Finally, the potential of this formulation approach for nutraceuticals delivery is critically discussed. Key findingsThe self-emulsifying formulations have potential to augment the oral bioavailability and consequently therapeutic efficacy of nutraceuticals by various mechanisms such as reduction in intra-enterocyte metabolism by cytochrome P450 enzymes, inhibiting P-glycoprotein (P-gp) efflux transporter and bypass hepatic first-pass metabolism through lymphatic pathway. ConclusionSelf-emulsifying formulations have emerged as preferable system for the formulation of nutraceuticals because of their ease of large-scale production, higher loading capacity, better dissolution behaviour of poorly water-soluble nutraceuticals, enhancement of oral bioavailability and their commercial potential.