Formulation and optimization of nanostructured lipid carriers to enhance oral bioavailability of telmisartan using Box–Behnken design

Abstract

The aim of the present study was to formulate and optimize nanostructured lipid carriers (NLC) to enhance oral bioavailability of telmisartan. “Box-Behnken design (3-factor, 3-level)” was utilized for the optimization of formulation. The independent variables were total lipid concentration (A), surfactant concentration (B), and sonication time (C) while particle size (R1), polydispersity index (PDI, R2), and entrapment efficiency (R3) were the dependent variables. The in vitro drug release, tissue uptake, and in vivo pharmacokinetic study of the optimized formulation were investigated. The particle size, PDI, entrapment efficiency, and zeta potential values of the optimized formulation were 172.50 ± 8.47 nm, 0.272 ± 0.029, 83.72 ± 3.85%, and −35 mV, respectively. The tissue uptake study confirmed that the rhodamine B loaded NLC was efficiently absorbed into the rat small intestine compared to the control formulation. The pharmacokinetic study revealed that the relative bioavailability of the telmisartan loaded NLC was increased by 2.17 and 3.46 fold compared to that of the marketed formulation and pure drug suspension, respectively. We concluded that the telmisartan loaded NLC was successfully optimized using the “Box–Behnken design”, which enhanced the oral bioavailability of telmisartan in Wistar rats and merits further investigations.