title: Design and optimization of self-nanoemulsifying drug delivery systems for improved bioavailability of cyclovirobuxine D.
abstract: BACKGROUND
  The main purpose of this research was to design a self-nanoemulsifying drug delivery system (SNEDDS) for improving the bioavailability of cyclovirobuxine D as a poorly water-soluble drug.
  
  
  METHODS
  Solubility trials, emulsifying studies, and pseudo-ternary phase diagrams were used to screen the SNEDDS formulations. The optimized drug-loaded SNEDDS was prepared at a mass ratio of 3:24:38:38 for cyclovirobuxine D, oleic acid, Solutol SH15, and propylene glycol, respectively. The optimized formulation was characterized in terms of physicochemical and pharmacokinetic parameters compared with marketed cyclovirobuxine D tablets.
  
  
  RESULTS
  The optimized cyclovirobuxine-D-loaded SNEDDS was spontaneously dispersed to form a nanoemulsion with a globule size of 64.80±3.58 nm, which exhibited significant improvement of drug solubility, rapid absorption rate, and enhanced area under the curve, together with increased permeation and decreased efflux. Fortunately, there was a nonsignificant cytotoxic effect toward Caco-2 cells. The relative bioavailability of SNEDDS was 200.22% in comparison with market tablets, in rabbits.
  
  
  CONCLUSIONS
  SNEDDS could be a potential candidate for an oral dosage form of cyclovirobuxine D with improved bioavailability.
authors.affiliation: Nanjing University of Chinese Medicine, Nanjing, Jiangsu; Huangshan University, Huangshan, Anhui; Third Clinical Medical College, Nanjing University of Chinese Medicine, Nanjing, Jiangsu.
authors.forename: Zhongcheng
authors.initials: Z
authors.lastname: Ke
authors.affiliation: Anhui University of Chinese Medicine, Hefei, Anhui, People's Republic of China.
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Hou
authors.affiliation: Third Clinical Medical College, Nanjing University of Chinese Medicine, Nanjing, Jiangsu.
authors.forename: Xiao-Bin
authors.initials: XB
authors.lastname: Jia
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001682:Biological Availability; D018938:Caco-2 Cells; D004337:Drug Carriers / Q000737:chemistry*; D016503:Drug Delivery Systems / Q000379:methods*; D004365:Drugs, Chinese Herbal / Q000008:administration & dosage / Q000737:chemistry* / Q000494:pharmacology*; D004655:Emulsions / Q000737:chemistry*; D006801:Humans; D053758:Nanoparticles / Q000737:chemistry*; D019301:Oleic Acid / Q000737:chemistry* / Q000494:pharmacology*; D011817:Rabbits; D017208:Rats, Wistar; D013607:Tablets
chemical_list: D004337:Drug Carriers; D004365:Drugs, Chinese Herbal; D004655:Emulsions; D013607:Tablets; D019301:Oleic Acid; C032939:cyclovirobuxine D
keywords: bioavailability; cyclovirobuxine D; self-nanoemulsifying drug delivery