title: Intestinal fluid volumes and transit of dosage forms as assessed by magnetic resonance imaging.
abstract: OBJECTIVE
  The gastrointestinal transit of sequentially administered capsules was investigated in relation to the availability of fluid along the intestinal lumen by magnetic resonance imaging.
  
  
  METHODS
  Water-sensitive magnetic resonance imaging was performed on 12 healthy subjects during fasting and 1 h after a meal. Specifiable non-disintegrating capsules were administered at 7, 4 and 1 h prior to imaging.
  
  
  RESULTS
  While food intake reduced the mean fluid volumes in the small intestine (105 +/- 72 mL vs. 54 +/- 41 mL, P < 0.01) it had no significant effect on the mean fluid volumes in the colon (13 +/- 12 mL vs. 18 +/- 26 mL). The mean number of separated fluid pockets increased in both organs after meal (small intestine: 4 vs. 6, P < 0.05; large intestine: 4 vs. 6, P < 0.05). The distribution of capsules between the small and large intestine was strongly influenced by food (colon: 3 vs. 17 capsules, P < 0.01).
  
  
  CONCLUSIONS
  The results show that fluid is not homogeneously distributed along the gut, which likely contributes to the individual variability of drug absorption. Furthermore, transport of fluid and solids through the ileocaecal valve is obviously initiated by a meal-induced gastro-ileocaecal reflex.
authors.affiliation: Department of Biopharmaceutics and Pharmaceutical Technology, University of Greifswald, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Schiller
authors.forename: C-P
authors.initials: CP
authors.lastname: Fröhlich
authors.forename: T
authors.initials: T
authors.lastname: Giessmann
authors.forename: W
authors.initials: W
authors.lastname: Siegmund
authors.forename: H
authors.initials: H
authors.lastname: Mönnikes
authors.forename: N
authors.initials: N
authors.lastname: Hosten
authors.forename: W
authors.initials: W
authors.lastname: Weitschies
mesh_terms: D000328:Adult; D001834:Body Water / Q000502:physiology*; D002214:Capsules; D003106:Colon / Q000378:metabolism; D005260:Female; D005772:Gastrointestinal Transit / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged
chemical_list: D002214:Capsules