title: A phospholipid complex to improve the oral bioavailability of flavonoids.
abstract: OBJECTIVE
  A phospholipid complex (TFH-PC) was prepared to increase the oral bioavailability of isorhamnetin, kaempferol, and quercetin from TFH (total flavones of Hippophae rhamnoides L.).
  
  
  METHODS
  Solvent evaporation was used to prepare TFH-PC. Relevant parameters were investigated based on the complexation rate of isorhamnetin, kaempferol, and quercetin. Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), X-ray power diffraction (X-RPD), and scanning electron microscopy (SEM) were used for characterization. Solubility, octanol-water partition coefficient (log P), dissolution rate, and in vivo pharmacokinetics were also investigated.
  
  
  RESULTS
  TFH-PC was successfully prepared in tetrahydrofuran with a drug to phospholipid ratio of 1:1, reaction temperature of 20 °C, and a reaction time of 1 h. The complexation rates of isorhamnetin, kaempferol, and quercetin were 97.7%, 95.97%, and 92.23%, respectively. FT-IR, DSC, X-RPD, and SEM confirmed the formation of TFH-PC. The aqueous solubilities of the three flavonoids in TFH-PC increased 22.0-26.8-fold compared with TFH. The dissolution of isorhamnetin, kaempferol, and quercetin in TFH-PC was 84.32%, 90.77%, and 100% within 10 min, respectively, greatly improved over TFH. After oral administration of TFH-PC in rats, the bioavailability of isorhamnetin, kaempferol, and quercetin in TFH-PC relative to TFH was 223%, 172%, and 242%, respectively.
  
  
  CONCLUSIONS
  The oral absorption of isorhamnetin, kaempferol, and quercetin was significantly improved in TFH-PC, mainly due to increased solubility and dissolution rate. This phospholipid complex shows potential for oral delivery of the flavonoids in TFH.
authors.affiliation: a Research Center for Health and Nutrition , Shanghai University of Traditional Chinese Medicine , Shanghai , China .|b Department of Pharmacy , Xiangshan Hospital of Traditional Chinese Medicine , Shanghai , China .
authors.forename: Huizhen
authors.initials: H
authors.lastname: Wang
authors.affiliation: a Research Center for Health and Nutrition , Shanghai University of Traditional Chinese Medicine , Shanghai , China .
authors.forename: Yuqing
authors.initials: Y
authors.lastname: Cui
authors.affiliation: c Institute of Chinese Materia Medica , Shanghai University of Traditional Chinese Medicine , Shanghai , China , and.
authors.forename: Qingxue
authors.initials: Q
authors.lastname: Fu
authors.affiliation: a Research Center for Health and Nutrition , Shanghai University of Traditional Chinese Medicine , Shanghai , China .
authors.forename: Bing
authors.initials: B
authors.lastname: Deng
authors.affiliation: d Department of Pharmacy , Shanghai TCM-integrated Hospital , Shanghai , China.
authors.forename: Guowen
authors.initials: G
authors.lastname: Li
authors.affiliation: b Department of Pharmacy , Xiangshan Hospital of Traditional Chinese Medicine , Shanghai , China .
authors.forename: Jun
authors.initials: J
authors.lastname: Yang
authors.affiliation: c Institute of Chinese Materia Medica , Shanghai University of Traditional Chinese Medicine , Shanghai , China , and.
authors.forename: Tao
authors.initials: T
authors.lastname: Wu
authors.affiliation: a Research Center for Health and Nutrition , Shanghai University of Traditional Chinese Medicine , Shanghai , China .
authors.forename: Yan
authors.initials: Y
authors.lastname: Xie
mesh_terms: D000818:Animals; D019540:Area Under Curve; D001682:Biological Availability; D002152:Calorimetry, Differential Scanning; D016503:Drug Delivery Systems / Q000379:methods*; D065546:Drug Liberation; D047309:Flavones / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D006207:Half-Life; D031281:Hippophae; D044949:Kaempferols / Q000008:administration & dosage / Q000493:pharmacokinetics; D008297:Male; D008657:Metabolic Clearance Rate; D008855:Microscopy, Electron, Scanning; D010743:Phospholipids / Q000737:chemistry*; D033362:Powder Diffraction; D011794:Quercetin / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000493:pharmacokinetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D013678:Technology, Pharmaceutical
chemical_list: D047309:Flavones; D044949:Kaempferols; D010743:Phospholipids; C047368:3-methylquercetin; C006552:kaempferol; D011794:Quercetin
keywords: Dissolution rate; flavonoids; oral absorption; phospholipid complex; solubility