Formulation, Characterization and In Vivo Evaluation of Self-Nanoemulsifying Drug Delivery System for Oral Delivery of Valsartan

Abstract

Valsartan is an effective, highly selective and orally active antihypertensive exhibiting low aqueous solubility and poor dissolution that limit its absorption resulting in low bioavailability. The objective of the present study was to prepare and characterize selfnanoemulsifying drug delivery system (SNEDDS) of Valsartan and evaluate their performance in animal models. SNEDDS was prepared by the spontaneous emulsification method. Saturation solubility of the drug was studied in various oils, surfactants and co-surfactants. The formulations were characterized for droplet size, shape, DSC, FTIR, in vitro drug release and for pharmacokinetic studies in Wistar rats. SNEDDS were prepared using triacetin and castor oil as oil phase, Tween 80 as surfactant and PEG 600 as co-surfactant. The globule size was 139.29 ± 10.5 nm for triacetin SNEDDS and 142.6 ± 18.6 nm for castor oil SNEDDS when diluted with 500-fold volume of the Milli-Q water. TEM images confirmed the uniform shape and nano size of the system. The formulations were stable on storage at accelerated conditions. The SNEDDS significantly increased the Cmax and area under the curve (AUC) compared to that of the pure Valsartan. Thus SNEDDS can be effectively used to improve the oral bioavailability of Valsartan.