Mixed surfactant based (SNEDDS) self-nanoemulsifying drug delivery system presenting efavirenz for enhancement of oral bioavailability.

Abstract This study aims to develop a self-nanoemulsifying drug delivery system (SNEDDS) based on non-ionic surfactant mixtures to improve the oral bioavailability of efavirenz (EFZ) categorized as a class II according to the BCS, for HIV- therapy. The result of solubility studies of EFZ in various excipients utilized for construction of the pseudo ternary phase diagram containing surfactant mixtures. Surfactants in 1:1 combination are used with different co-surfactants in different ratio to delineate the area of monophasic region of the pseudo ternary phase diagram. Different accelerated physical stability studies and self-emulsification assessment were performed on the formulations. The formulations clearing the above studies are considered for percentage transmittance and turbidity analysis. The globule size distributions of post diluted SNEDDS having percentage transmittance above 90 were estimated. The TEM analysis of two optimized post diluted SNEDDS formulations further confirm the size in nanometric range (below 50 nm). FT-IR studies showed the retention of the characteristic peaks of EFZ in the preconcentrate. The in vitro dissolution profile of SNEDDS established advantages of SNEDDS over plain drug as more than 80% drug was released within 30 min in case of optimized SNEDDS while it was approximately 18.3% in the case of plain drug powder. Pharmacokinetic parameters were calculated after performing the in vivo studies of best optimized formulation in rats. The Pharmacokinetic data reveal a 2.63 fold increase in AUC (0-∞) in comparison to plain EFZ suspension. The designed delivery system showed the faith in generating an effective formulation of EFZ for HIV treatment.