title: The formation of a host-guest inclusion complex system between β-cyclodextrin and baicalin and its dissolution characteristics.
abstract: OBJECTIVE
  Baicalin (BCL) has potential therapeutic benefits, but its clinical outcomes are restricted mainly because of low water solubility. This study sought to improve the water solubility of BCL by the formation of inclusion complex with β-cyclodextrin (β-CD).
  
  
  METHODS
  The inclusion complex was studied by solubility test, differential scanning calorimeter (DSC), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD),1H Nuclear magnetic resonance (1HNMR) and scanning electron microscopy (SEM). Molecular docking was conducted to verify the experimental findings. The dissolution rate was determined by dialysis membrane method. In vivo absorption studies in rats were conducted and high-performance liquid chromatography (HPLC) was used to analyse the plasma level of BCL after oral administration.
  
  
  RESULTS
  The DSC, FTIR, XRD,1HNMR and SEM findings suggested the formation of inclusion complex between BCL and β-CD in 1 : 1 stoichiometry. Molecular docking demonstrated the insertion of benzene ring of BCL into β-CD cavity by hydrophobic interactions and possible H-bond formation. Moreover, β-CD markedly improved the solubility of BCL and displayed AL-type phase diagrams. The improvement in dissolution rate of the inclusion complex was reflected in the earlier Tmax, higher Cmaxand larger AUC0-tthan that of BCL after oral administration.
  
  
  CONCLUSIONS
  β-cyclodextrin complex can be used as an effective formulation strategy for development of BCL-loaded delivery system with better therapeutic outcomes.
authors.affiliation: Department of Medicinal Chemistry, School of Pharmacy, Chongqing Medical University, Chongqing, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Medicinal Chemistry, School of Pharmacy, Chongqing Medical University, Chongqing, China.
authors.forename: Qihua
authors.initials: Q
authors.lastname: Jiang
authors.affiliation: Department of Medicinal Chemistry, School of Pharmacy, Chongqing Medical University, Chongqing, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Deng
authors.affiliation: Department of Medicinal Chemistry, School of Pharmacy, Chongqing Medical University, Chongqing, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Department of Medicinal Chemistry, School of Pharmacy, Chongqing Medical University, Chongqing, China.
authors.forename: Mingan
authors.initials: M
authors.lastname: Yu
authors.affiliation: Department of Pharmaceutical Analysis, School of Pharmacy, Chongqing Medical University, Chongqing, China.|Chongqing Key Laboratory of Biochemistry and Molecular Pharmacology, Chongqing Medical University, Chongqing, China.
authors.forename: Jingchuan
authors.initials: J
authors.lastname: Shang
authors.affiliation: Department of Medicinal Chemistry, School of Pharmacy, Chongqing Medical University, Chongqing, China.|Chongqing Key Laboratory of Biochemistry and Molecular Pharmacology, Chongqing Medical University, Chongqing, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Li
mesh_terms: D000818:Animals; D001682:Biological Availability; D002152:Calorimetry, Differential Scanning / Q000379:methods; D002626:Chemistry, Pharmaceutical / Q000379:methods; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005419:Flavonoids / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D008297:Male; D062105:Molecular Docking Simulation / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D014961:X-Ray Diffraction / Q000379:methods; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D005419:Flavonoids; D047392:beta-Cyclodextrins; C038044:baicalin
keywords: baicalin; bioavailability; inclusion complex; molecular docking; β-cyclodextrin