Impact of oil type on the development and oral bioavailability of self-nanoemulsifying drug delivery systems containing simvastatin

Abstract

The aim of this work is to develop and evaluate self-nanoemulsifying drug delivery systems (SNEDDS) containing simvastatin to increase its oral bioavailability. Formulation EO 5 (Ethyl oleate 9.3% w/w: Tween 80 49.4% w/w: Propylene glycol 39.3% w/w) and Formulation CL 14 (Clove oil 54.3% w/w: Tween 80 34.4% w/w: Transcutol-P 9.3% w/w) were thoroughly studied. They showed emulsification time less than 1 min, droplet size in the nanometric range, and almost a complete drug release after 2 h. The in-vitro dissolution profile of both formulations was found to be significant in comparison to the pure drug in pH 1.2 and 7.4 buffers (P < 0.0001). Furthermore, they demonstrated superior anti-hyperlipidemic activity in comparison to simvastatin suspension (10 mg/kg/day). In order to investigate the impact of oil type on oral bioavailability, the selected formulations have been examined in terms of the in-vivo pharmacokinetic study, and formulation EO 5 was found to have higher bioavailability. After oral administration of a single dose (40 mg/kg) of simvastatin-loaded SNEDDS (CL14 and EO 5), a 1.5-fold and 1.95-fold increase in bioavailability were observed, respectively, as compared to simvastatin suspension. Hence, the results indicated that the developed SNEDDS could enhance the therapeutic efficacy and oral bioavailability of simvastatin.