Enhancement of Oral Bioavailability of Tripterine Through Lipid Nanospheres: Preparation, Characterization, and Absorption Evaluation

Oral delivery of anticancer drugs remains challenging because of limited water-solubility and/or poor permeability. Here, we aimed to enhance the oral bioavailability of tripterine (TRI, a plant-derived anticancer compound) using lipid nanospheres (LNs) and to determine the mechanisms of oral absorption. TRI-loaded LNs (TRI-LNs) were prepared by rapid dispersion of an ethanol mixture of TRI, lecithin, sodium oleate, and soybean oil into water. The obtained LNs were 150 nm in size with a high value of entrapment efficiency (99.95%). TRI-LNs were fairly stable and the drug release was negligible (< 0.2%) in simulated physiological fluid. The pharmacokinetic results showed that LNs significantly enhanced the oral bioavailability of TRI with a relative bioavailability of 224.88% (TRI suspensions was used as a reference). The mechanistic studies demonstrated that improved intestinal permeability and post-enterocyte lymphatic transport were mainly responsible for the enhanced oral absorption. Our findings suggested that LNs may be a viable oral carrier for poorly bioavailable drugs. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 103:171 1-1719, 2014