title: Pharmacokinetics of four 5-FU preparations administered rectally to rats and rabbits.
abstract: OBJECTIVE
  To compare the pharmacokinetic characteristics of four preparations of fluorouracil (5-FU) administered rectally using a rat model.
  
  
  METHODS
  Concentrations of 5-FU were measured in plasma, the rectal wall and mesentery lymph tissues of rats and rabbits by high performance liquid chromatography. Differences between the main pharmacokinetic parameters were compared by statistical analysis.
  
  
  RESULTS
  The 5-FU concentrations in the rectal wall and mesenteric lymph tissues were significantly higher than the concentration in blood following rectal administration for all four of the preparations (P < 0.01). The drug level in the rectal wall was higher in the animals received delivery of an emulsion, compared to those who received delivery as a suppository (P < 0.05). Moreover, the animals who received a lipophil-based suppository had lower plasma level of drug than those who received a hydrophil-based suppository, and the animals who received the simple (o/w) emulsion had lower plasma level than those who received the complex (w/o/w) emulsion. The differences found in the rat model were confirmed in rabbits (P < 0.01).
  
  
  CONCLUSIONS
  The lipophil-based suppository and the simple emulsion of 5-FU might be more suitable for rectal administration for treatment of rectal cancers.
authors.affiliation: Xiang Zhang, Bao-Dong Ling, Department of Pharmacology, North Sichuan Medical College, Nanchong 637007, Sichuan Province, China.
authors.forename: X
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Xiang Zhang, Bao-Dong Ling, Department of Pharmacology, North Sichuan Medical College, Nanchong 637007, Sichuan Province, China.
authors.forename: C S
authors.initials: CS
authors.lastname: Wang
authors.affiliation: Xiang Zhang, Bao-Dong Ling, Department of Pharmacology, North Sichuan Medical College, Nanchong 637007, Sichuan Province, China.
authors.forename: G Z
authors.initials: GZ
authors.lastname: Wu
authors.affiliation: Xiang Zhang, Bao-Dong Ling, Department of Pharmacology, North Sichuan Medical College, Nanchong 637007, Sichuan Province, China.
authors.forename: B D
authors.initials: BD
authors.lastname: Ling
authors.affiliation: Xiang Zhang, Bao-Dong Ling, Department of Pharmacology, North Sichuan Medical College, Nanchong 637007, Sichuan Province, China.
authors.forename: R H
authors.initials: RH
authors.lastname: Liang
authors.affiliation: Xiang Zhang, Bao-Dong Ling, Department of Pharmacology, North Sichuan Medical College, Nanchong 637007, Sichuan Province, China.
authors.forename: X S
authors.initials: XS
authors.lastname: Fang
authors.affiliation: Xiang Zhang, Bao-Dong Ling, Department of Pharmacology, North Sichuan Medical College, Nanchong 637007, Sichuan Province, China.
authors.forename: T Y
authors.initials: TY
authors.lastname: Xin
keywords: Fluorouracil/phamarcokinetics; Rectal administration; Rectal neoplasms/drug therapy