title: Molecular complexation of curcumin with pH sensitive cationic copolymer enhances the aqueous solubility, stability and bioavailability of curcumin.
abstract: Curcumin is a natural dietary compound with demonstrated potential in preventing/treating several chronic diseases in animal models. However, this success is yet to be translated to humans mainly because of its poor oral bioavailability caused by extremely low water solubility. This manuscript demonstrates that water insoluble curcumin (~1μg/ml) forms highly aqueous soluble complexes (>2mg/ml) with a safe pH sensitive polymer, poly(butyl-methacrylate-co-(2-dimethylaminoethyl) methacrylate-co-methyl-methacrylate) when precipitated together in water. The complexation process was optimized to enhance curcumin loading by varying several formulation factors. Acetone as a solvent and polyvinyl alcohol as a stabilizer with 1:2 ratio of drug to polymer yielded complexes with relatively high loading (~280μg/ml) and enhanced solubility (>2mg/ml). The complexes were amorphous in solid and were soluble only in buffers with pHs less than 5.0. Hydrogen bond formation and hydrophobic interactions between curcumin and the polymer were recorded by infrared spectroscopy and nuclear magnetic resonance spectroscopy, respectively. Molecular complexes of curcumin were more stable at various pHs compared to unformulated curcumin. In mice, these complexes increased peak plasma concentration of curcumin by 6 times and oral bioavailability by ~20 times. This is a simple, economic and safer strategy of enhancing the oral bioavailability of curcumin.
authors.affiliation: Department of Pharmaceutical Sciences, College of Pharmacy, South Dakota State University, SAV # 255, Box 2202C, Brookings, SD 57007, United States.
authors.forename: Sunny
authors.initials: S
authors.lastname: Kumar
authors.affiliation: Department of Pharmaceutical Sciences, College of Pharmacy, South Dakota State University, SAV # 255, Box 2202C, Brookings, SD 57007, United States.
authors.forename: Siddharth S
authors.initials: SS
authors.lastname: Kesharwani
authors.affiliation: Department of Pharmaceutical Sciences, College of Pharmacy, South Dakota State University, SAV # 255, Box 2202C, Brookings, SD 57007, United States.
authors.forename: Himanshi
authors.initials: H
authors.lastname: Mathur
authors.affiliation: Department of Pharmaceutical Sciences, College of Pharmacy, South Dakota State University, SAV # 255, Box 2202C, Brookings, SD 57007, United States.
authors.forename: Mohit
authors.initials: M
authors.lastname: Tyagi
authors.affiliation: Department of Pharmaceutical Sciences, College of Pharmacy, South Dakota State University, SAV # 255, Box 2202C, Brookings, SD 57007, United States.
authors.forename: G Jayarama
authors.initials: GJ
authors.lastname: Bhat
authors.affiliation: Department of Pharmaceutical Sciences, College of Pharmacy, South Dakota State University, SAV # 255, Box 2202C, Brookings, SD 57007, United States. Electronic address: hemachand.tummala@sdstate.edu.
authors.forename: Hemachand
authors.initials: H
authors.lastname: Tummala
mesh_terms: D000818:Animals; D001682:Biological Availability; D003474:Curcumin / Q000737:chemistry* / Q000493:pharmacokinetics*; D004355:Drug Stability; D006860:Hydrogen Bonding; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D008807:Mice, Inbred BALB C; D011109:Polymethacrylic Acids / Q000737:chemistry* / Q000493:pharmacokinetics*; D012995:Solubility
chemical_list: D011109:Polymethacrylic Acids; C518398:Eudragit E PO; D003474:Curcumin
keywords: Bioavailability; Curcumin; Eudragit® EPO; Molecular complexation; Oral delivery; Solubility; Stability