Supersaturable self-emulsifying drug delivery system: A strategy for improving the loading and oral bioavailability of quercetin

Abstract

Supersaturable Lipid based drug delivery systems have gained much attention as bio-enabling formulation approach for oral delivery of drugs with high dose. Hence, the present investigation involves the preparation of quercetin (QT) loaded supersaturable self-emulsifying drug delivery system (QT-sSEDDS). Capmul® MCM EP, Tween® 20 and ethanol were used as chief components of preconcentrate which were selected based on solubility studies. Precipitation inhibitors (PI) were screened based on apparent drug concentration profile with respect to time where, HPMC E5 at 2.5% w/w was found suitable for the desired purpose. The QT-sSEDDS were characterised for their size, stability, functional stability and precipitate characterization, which revealed promising results. Further, solubilisation potential of QT-sSEDDS was evaluated using pH-stat lipolysis method which revealed ∼1.25 fold higher %QT content in aqueous state in comparison to QT-sSEDDS without PI. The cell uptake studies on Caco-2 cells (qualitative and quantitative) revealed significantly higher uptake in case of sSEDDS (Coumarin-6 or QT loaded) over free groups. These in vitro results were corroborated by in vivo pharmacokinetic data where, QT-sSEDDS revealed ∼2.2 and 2-fold increase in Cmax (at 4 h) and AUC respectively in comparison to conventional QT-SEDDS. Hence, it can be suggested that sSEDDS can potentially be used in delivering poorly soluble drug, QT which shows dose dependent bioavailability.