Efavirenz Self-Nano-Emulsifying Drug Delivery System: In Vitro and In Vivo Evaluation

Self-emulsifying drug delivery system (SEDDS) is the isotropic and thermodynamically stable mixture of oil, surfactant, co-solvent/surfactant, and drug. It emulsifies spontaneously when introduced into an aqueous phase under a mild agitation. The current study was aimed to prepare SNEDDS to augment solubility, release rate, and oral bioavailability of BCS class II drug, efavirenz (EFV). A series of oil, surfactant, and co-surfactant was screened out by a ternary phase diagram to locate a better homogenous mixture. The prepared SNEDDS was evaluated regarding its appearance, mean droplet size, phase separation, in vitro drug release, and oral bioavailability. Among the screened oil, surfactant, and co-surfactant, Labrafil M 2125 CS, Tween 80, and Transcutol®P mixture exhibited superior solubilizing capacity, respectively. Optimized SNEDDS exhibits 98.39% drug release. SNEDDS dissolution behavior was attributed to oil/surfactant ratios and properties of the surfactant phase. It also demonstrates threefold increments in the area under curve (AUC) in comparison to neat EFV. Furthermore, the optimized SNEDDS does not show any vitrification during its 3-month storage. In the present study, better performance of SNEDDS is explained by various factors like (i) improved surface area of droplets, (ii) superior solubilization potential for hydrophobic drugs due to Labrafil M 2125 CS, and (iii) result of surfactant on mucosal permeability. This study demonstrated that SNEDDS may be an alternative approach for the poorly soluble drugs to improve their solubility and oral bioavailability.