International Journal of Nanomedicine (Feb 2017)
Fabrication and in vitro/in vivo evaluation of amorphous andrographolide nanosuspensions stabilized by D-α-tocopheryl polyethylene glycol 1000 succinate/sodium lauryl sulfate
Abstract
Hongzhi Qiao,1,2,* Lihua Chen,3,* Tianqi Rui,1,2 Jingxian Wang,1,2 Ting Chen,1,2 Tingming Fu,1,2 Junsong Li,1,2 Liuqing Di1,2 1College of Pharmacy, Nanjing University of Chinese Medicine, 2Jiangsu Engineering Research Center for Efficient Delivery System of TCM, Nanjing, 3Key Laboratory of Modern Preparation of Traditional Chinese Medicine, Ministry of Education, Jiangxi University of Traditional Chinese Medicine, Nanchang, China *These authors contributed equally to this work Abstract: Andrographolide (ADG) is a diterpenoid isolated from Andrographis paniculata with a wide spectrum of biological activities, including anti-inflammatory, anticancer and hepatoprotective effects. However, its poor water solubility and efflux by P-glycoprotein have resulted in lower bioavailability. In this study, ADG nanosuspensions (ADG-NS) were prepared using a wet media milling technique followed by freeze drying. D-α-Tocopheryl polyethylene glycol 1000 succinate (TPGS), a surfactant that inhibits P-glycoprotein function, and sodium lauryl sulfate were used as surface stabilizers. A Box–Behnken design was used to optimize the nanosuspension preparation. The products of these optimal preparation conditions were amorphous and possessed much faster dissolution in vitro than a coarse powder of ADG. The particle size and redispersibility index of the freeze-dried ADG-NS were 244.6±3.0 nm and 113%±1.14% (n=3), respectively. A short-term stability study indicated that the freeze-dried ADG-NS could remain highly stable as nanosuspensions during the testing period. A test of transport across a Caco-2 cell monolayer revealed that the membrane permeability (Papp) of ADG-NS was significantly higher than the permeability of the ADG coarse powder or ADG-NS without TPGS (P<0.01). Compared to the ADG coarse powder, a physical mixture, commercial dripping pills and ADG-NS without TPGS, ADG-NS exhibited significantly higher plasma exposure with significant enhancements in Cmax and area under the curve of plasma concentration versus time from zero to the last sampling time (AUC0–t) (P<0.01). An evaluation of the anti-inflammatory effect on Carr-induced paw edema demonstrated that the ADG-NS were more effective in reducing the rate of paw swelling, producing a greater increase in the serum levels of nitric oxide (NO), Interleukin-1 (IL-1) and tumor necrosis factor-α (TNF-α) (P<0.01) and an increase in superoxide dismutase activity (P<0.05) compared to the ADG coarse powder. This study indicated that nanosuspensions could act as an effective delivery device for ADG to enhance its oral bioavailability and biological efficacy. Keywords: andrographolide, nanosuspensions, Box–Behnken design, D-α-tocopheryl polyethylene glycol 1000 succinate, dissolution rate, oral bioavailability
