Development and optimization of self-nanoemulsifying drug delivery system with enhanced bioavailability by Box-Behnken design and desirability function.

The aim of our study was to characterize and optimize a self-nanoemulsifying drug delivery system (SNEDDS) formulation by a three-factor, three-level Box-Behnken design (BBD) combined with a desirability function. The independent factors were the amounts of Capryol PGMC (X(1)), Tween 20 (X(2)), and Transcutol HP (X(3)). The dependent variables were droplet size (Y(1)), equilibrium solubility (Y(2)), and cumulative percentage of drug released in 15 min (Y(3)) from the SNEDDS formulation. The responses were fitted to a second-order quadratic model and statistical validation of the fitted models was carried out by analysis of variance. Various response surface graphs and contour plots were constructed to understand the effects of different factor level combinations on the responses. The optimized SNEDDS formulation consisting of Capryol PGMC-Tween 20-Transcutol HP at proportions of 5:58.4:40 (w/w) was prepared and a comparison of the predicted values and experimental values was found to be in close agreement. Furthermore, an in vivo pharmacokinetic study of the optimized SNEDDS formulation showed a 2.2-fold increase in relative oral bioavailability compared with that of the suspension. In conclusion, the BBD demonstrated its effectiveness in optimizing the SNEDDS formulation and in understanding the effects of formulation variables on the performance of SNEDDS.