title: [Studies on O/W partition coefficient and absorption kinetics of geniposide in fructus gardeniae extract in rat intestine].
abstract: OBJECTIVE
  To determine the O/W partition coefficient of geniposide in fructus gardeniae extract and investigate the absortion kinetics of geniposide in whole small intestine and different intestinal segments of rats.
  
  
  METHODS
  The shake-flask method was employed to determine the O/W partition coefficient of geniposide; an in situ intestinal perfusion model was employed to investigate the absorptive kinetics of geniposide.
  
  
  RESULTS
  The partition coefficient (P) of geniposide was 0.1077, logP was -0.9678; the absorptive rate constants (K) of geniposide at the concentration of 0.078, 0.311, 0.780 g x L(-1) were (0.130 +/- 0.007), (0.056 +/- 0.003), (0.031 +/- 0.006) h, respectively. The K of geniposide were (0.019 +/- 0.003), (0.015 +/- 0.002), (0.012 +/- 0.002) h at duodenum, jejunum, ileum, respectively.
  
  
  CONCLUSIONS
  According to the P and the logP, it could be indicated that the absorption of geniposide at small intestine was poor absorption; The absorption rate was increased with the decrease of the extract concentration; Their absorption was first-order process besides the passive diffusion mechanism, and facilitated diffusion and active transport may also take part in the transport process. Geniposide was absorbed at all smallintestinal segments of rats, but the duodenal absorption ratewas higher more than other section.
authors.affiliation: School of Chinese Pharmacy, Beijing University of Traditional Chinese Medicine, Beijing 100102, China.
authors.forename: Qianyi
authors.initials: Q
authors.lastname: Zhang
authors.forename: Shouying
authors.initials: S
authors.lastname: Du
authors.forename: Yang
authors.initials: Y
authors.lastname: Lu
authors.forename: Xiuli
authors.initials: X
authors.lastname: Rao
mesh_terms: D000818:Animals; D004365:Drugs, Chinese Herbal / Q000737:chemistry / Q000493:pharmacokinetics*; D032062:Gardenia / Q000737:chemistry*; D007408:Intestinal Absorption / Q000187:drug effects; D007422:Intestines / Q000187:drug effects / Q000502:physiology; D039823:Iridoids / Q000737:chemistry / Q000493:pharmacokinetics*; D007700:Kinetics; D008297:Male; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D004365:Drugs, Chinese Herbal; D039823:Iridoids; C007835:geniposide