Improving intestinal absorption and oral bioavailability of curcumin via taurocholic acid-modified nanostructured lipid carriers

Abstract

Cihui Tian,1 Sajid Asghar,2 Yifan Wu,1 Zhipeng Chen,3 Xin Jin,1 Lining Yin,1 Lin Huang,1 Qineng Ping,1 Yanyu Xiao1 1Department of Pharmaceutics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China; 2Faculty of Pharmaceutical Sciences, Government College University Faisalabad, Faisalabad, Pakistan; 3Department of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, China Abstract: The expression of multiple receptors on intestinal epithelial cells enables an actively targeted carrier to significantly enhance the oral delivery of payloads. Conjugating the receptors’ ligands on the surfaces of a particulate-delivery system allows site-specific targeting. Here, we used taurocholic acid (TCA) as a ligand for uptake of nanostructured lipid carriers (NLCs) mediated by a bile-acid transporter to improve oral bioavailability of curcumin (Cur). First, synthesis of TCA–polyethylene glycol 100–monostearate (S100-TCA) was carried out. Then, the physical and chemical properties of S100-TCA-modified Cur-loaded NLCs (Cur-TCA NLCs) with varying levels of S100-TCA modifications were investigated. Small particle size (<150 nm), high drug encapsulation (>90%), drug loading (about 3%), negative ζ-potential (–7 to –3 mV), and sustained release were obtained. In situ intestinal perfusion studies demonstrated improved absorption rate and permeability coefficient of Cur-TCA NLCs. Depending on the degree of modification, Cur-TCA NLCs displayed about a five- to 15-fold higher area under the curve in rats after oral administration than unmodified Cur NLCs, which established that the addition of S100-TCA to the NLCs boosted absorption of Cur. Further investigations of TCA NLCs might reveal a bright future for effective oral delivery of poorly bioavailable drugs. Keywords: curcumin, nanostructured lipid carriers, taurocholic acid, oral administration, pharmacokinetics, bioavailability

Keywords

• Curcumin
• Nanostructured lipid carriers
• Taurocholic acid
• Oral administration
• Pharmacokinetics
• Bioavailability